The Living Environment (A2); Conservation Of Biodiversity (Complete) Flashcards
What is global diversity?
The variety and abundance of life on Earth
What does our survival depend on as humans?
Other species which we sheere planet Earth; provide wide range of ecological life-support services & resources we exploit
What is required to maintain the resources we exploit?
Sustainable development & conservation
What are the different resources collected from plants and animals and for what uses?
-Wood; used in manufacture of buildings, tools, furniture
-Fibres; cotton, wool, paper, silk, rayon
-Oils; vegetable & animal oils used in foods, lubricants, soaps
-Fuels; wood, charcoal, alcohol, vegetable oils
Food; plants, animals, fungi, algae
What are examples of plant species that have the potential for commercial cultivation?
-Potato bean of North America has a↑ protein content
-Morama Bean from dry areas of S Africa has protein content similar to soya, is drought resistant
-Yeheb Tree from Somalia makes edible nuts, is drought resistant, can grow in poor soils
-Many species in spinach family can grow in soil w/ high salt content—> may be used in crop breeding programmes to increase salt tolerance of crops grown in areas where irrigation has causes soil salinisation
-Perennial (grows all year round so no need to buy new seeds each year) variety of maize was discovered in Mexico. Reduces need for ploughing & so soil erosion
-Kernza= perennial cereal w/ similar advantages to perennial maize
Which animal species been investigated for domestication and what are they better adapted for?
-American Bison, Common Ostrich, Cane Rats, Emu, Giant Land Snails
-Often better adapted to local conditions than traditional livestock species
What is biomimetics and what does it involve?
-Use of knowledge of adaptations of other species to improve designs of manufactured items
-All species have evolved over long periods of time, developing adaptations that increase their chance of survival
-Some include structural features that help us design improved engineering structures & equipment
Biomimetics- vehicle design; why and how have bird wings been utilised for vehicle design?
-Splayed wingtip feathers of soaring birds ↓ wind turbulence & drag
-Copying feather structures has improved aircraft wing designs to help ↑ fuel efficiency
Biomimetics- vehicle design; why and how have humpback whale flippers been utilised in vehicle design?
-Have tubercles (bumps) on flippers that channel water flow, ↑ hydrodynamic efficiency & allowing them to turn in tight circles when swimming around shoals of fish
-Has been applied to designs of ship rudders & aerogenerator blades
-New rudder design allows ships to turn in tighter circles. Aerogenerator blades can start to rotate at lower wind speeds than other designs so can generate more electricity
Biomimetics- vehicle design; why and how has shark skin been utilised in vehicle design?
-Has scales that reduce friction while swimming
-Ridges made by scales have been copied in new designs for aircraft & ship surface coatings to ↓ fuel consumption
Biomimetics- infection control; why and how has shark skin been used for infection control?
-Bacteria don’t easily stick to shark skin
-Coating material imitating shark skin is used in hospital operating theatres to help control bacterial infections
Biomimetics- architecture; why and how have the mounds that termites create above the ground been used in architecture design?
-Mounds that termites construct above ground absorb sunlight & become hot
-Hot air inside rises creating a convection current → draws state air out of lower parts of nest, creating a natural solar-driven ventilation system
-Air blowing over mound has a lower air pressure, draws air out of mound
-System has been copied in shopping complexes & office blocks to make natural ventilation & cooling w/out need for air conditioning
Biomimetics- architecture; why and how have birds and animals inspired architectural designs?
-Have structural features that give strength but are light
-Bird wing bones must be light & strong; are hollow, have internal struts preventing banes from bending too much/breaking
-This lightweight, strong structure has been copied in design of lightweight bridges & roofs
Biomimetics- adhesion; why and how have gecko lizards been used in designs for adhesion?
-Toes have pads providing strong adhesion
-Attempts are being made to copy this to provide adhesion w/out need for glue
Biomimetics- adhesion; why and how have the seeds of some plants been used in adhesion designs?
-Have burrs w/ hooks that can stick to fur of passing animals & aid seed dispersal
-Was copied in development of Velcro?
Biomimetics- adhesion; why and how have lotus flowers been used for adhesion designs?
-Have water-repelling properties
-Has been copied to make self-cleaning glass
Biomimetics- materials; why and how have some natural materials been used for synthetic material production?
-Have properties that can be applied to manufacture of synthetic materials
-The lightweight, flexible, strong silk made by spiders is being copied to make better car airbags & body armour
Medicines; how do some plants protect themselves from herbivores?
-Use thorns, spikes & bad tastes
-Produce chemicals toxic to animals that may eat them; many are alkaloids, can have beneficial medical effects in humans
Medicines- plant chemicals; how have chemicals produced by poppies been used to help humans?
Ave cultivated to make the painkillers morphine & codeine
Medicines- plant chemicals; how have chemicals produced by South American rainforest cinchona trees been used to help humans?
To produce quinine for malaria protection
Medicines- plant chemicals; how have the chemicals produced by willow trees been used to help humans?
Aspirin was extracted from willow trees; now manufactured synthetically
Medicines- plant chemicals; how have the chemicals produced by yew trees been used to help humans?
Taxol is extracted from them, used to treat a range of cancers, including breast, suarian, lung, bladder and prostate
Medicines- plant chemicals; how have the chemicals produced by Mexican yams from Central American rainforests been used to help humans?
Was the source of diosgenin, has been used to make steroid medicine including contraceptive pill & cortisone to ↓ inflammation & allergic reactions
Medicines- plant chemicals; how have the chemicals produced by tropical marine sponges in the Caribbean been used to help humans?
Drug AZT was discovered in them, is used to treat HIV/aids
Medicines- plant chemicals; how have the chemicals produced by shark liver lipids been used to help humans?
Alkylglycerols & polyunsaturated fatty acids are found in them, can suppress growth of cancer tumours
Medicines- plant chemicals; how have shark blood antibodies been used to help humans?
-Drug AD 114 is being tested as a cure for fibrosis of lungs
-Its based on an antibody extracted from shark blood
Medicines- plant chemicals; why are chemical substances with medicinal properties found in species a powerful argument to conserve other species?
-Only a very small proportion of species exist that have been studied for medicinal substances they may contain
-Species, or preferably entire habitats, should be conserved for the medicinal substances they may contain
Physiological research; how has studying marsupial young allowed better understanding of health problems in babies?
-Marsupials give birth to their young at a very early stage of development; they then develop in their mother’s pouch
-Studying a developing kangaroo/wallaby in pouch is easier than studying a human baby of the same age inside its mother’s womb
-This has helped in understanding developmental problems in unborn babies
Physiological research; how has studying hippopotamus skin helped improve health treatment?
-Secretes hipposudoric acid; a natural sunscreen & antimicrobial agent
-This is being studied to help improve treatment of burns victims
Physiological research; how have marine sponges been used for surgical developments?
-Produce proteins that prevent the rejection of grafts from other individuals
-These proteins are being developed to prevent rejection of human organs after transplant surgery
Physiological research; how have the embryos of Purple Sea Urchins been used to further medical developments?
-Used to test whether new medicines are teratogenic & could cause abnormal embryo development in humans
-Doesn’t threaten sea urchin populations as they’re a common species & a single female can produce 1/2 million eggs
-It’s not ethically acceptable to carry out tests directly on humans
Physiological research; how has studying dolphins and bats helped the development of medical diagnosis?
-Use high frequency sound to echo-locate their food
-Has enabled development of new ultrasound scanners that give better 3-D images for medical diagnosis
Physiological research; why and how has the study of squid nerves enabled a better understanding of diseases?
-Human nerve cells → very small & difficult to study, particularly the sodium/potassium pump across cell membranes
-Squid nerves = much larger & so easier to study
-Has provided better understanding of human heart disease, strokes, cancer, Alzheimer’s disease & kidney disease
Physiological research; why and how has the study of armadillos helped develop medical research?
-Are among the few animals that can catch the bacterial disease leprosy
-They’re used in the study of disease & vaccine production
Pest control species; what kind of natural predators’ populations can be increased and how?
-Ladybugs & ground beetles
-Can be ↑ by providing suitable habitats like hedgerows & beetle banks
Pest control species; what can be introduced to control weeds and especially which ones? + example
-Herbivores
-Especially if weed species is non-indigenous & isn’t eaten by indigenous herbivores
-Prickly pear cactus became a weed after its introduction to Australia from South America. Cactoblastis moth was successfully introduced from South America to control it
Pest control species; what can be introduced to control whitefly pests on crops like tomatoes?
Encarsia Formosa, a parasitic wasp which is released in greenhouses
Pest control species; what can be used to control insect crop pests and how?
Bacillus thuringiensis (Bt), a pathogenic bacterium
Produces proteins toxic to insects
Genetic resources- crop breeding programmes; what are Crop Wild Relative species (CWR) and why are they used?
-Domesticated crops often lack genetic diversity as have been produced from a limited number of original plants
-Search for new characteristics that can be bred into commercial crops focuses on wild plants of the same species/close relatives; often called Crop Wild Relative species (CWR)
Genetic resources- crop breeding programmes; where are many CWR species found and why?
-Areas where environmental degradation threatens their survival, eg Middle East, Central America, SE Asia
-Traditional varieties, grown in subsistence farming areas are also likely to have desirable characteristics not found in commercial varieties
Genetic resources- CWR species characteristics; what are examples of disease resistance being introduced from CWR species?
-Sugar cane has been protected from sugar cane mosaic virus by cross-breeding w/ a wild sugar cane variety from Indonesia
-A single wild species of tomato has provided genetic characteristics for resistance to 9 major diseases of commercially grown tomato varieties
Genetic resources- CWR species characteristics; what are examples of salt-tolerance being introduced from CWR species?
-Introduction of salt-tolerant characteristics from wild varieties of rice & barley has led to breeding of commercially cultivated varieties that can be grown in saline soil
-Sea kale= salt tolerant & has been studies for possible use in breeding programmes w/ closely related crop species
Genetic resources- CWR species characteristics; what is an example of drought resistance being introduced from CWR species?
Varieties of cacao, the source of chocolate, that are more drought-tolerant have been developed by cross-breeding w/ wild plants from Amazon rainforest
Genetic resources- CWR species characteristics; what is an example of high yields being introduced from CWR species?
Oil palm yields have been increased by 25% by cross-breeding w/ wild varieties found in central Africa
Genetic resources- CWR species characteristics; what are examples of improved taste/appearance being introduced from CWR species?
-Selective breeding from characteristics like post-harvest shelf life/improved appearance may result in loss of other desirable qualities like good taste. These characteristics can be re-introduced by further selective breeding
-More attractive, sweeter pineapples w/ yellower flesh have been produced by selective breeding since 1990s
Genetic resources- CWR species characteristics; what is an example of nutrient uptake being introduced from CWR species?
Many recently developed wheat varieties don’t form a strong link w/ mycorrhizal fungi in soil, reducing their ability to absorb nutrients like phosphate from soil
-Breeding programmes w/ wild wheat are increasing nutrient uptake efficiency by forming better associations betw wheat plants & mycorrhizal fungi
Genetic resources; what are Centres of Diversity and what are they also called?
Russian biologist Nikolai Vavilov studied crop genetics in early 1900s & realised some areas of the world had high conc of close relatives of important crop species
-These were named Centres of Diversity/Centres of Origin/Vavilov Centres
Genetic resources; what are the different Centres of Diversity?
-Mediterranean Centre; wheat, oats, pea, clover, olive
-Middle Eastern centre; wheat, barley, lentil, apple, pear
-Central Asian centre; wheat, peas, lentils, cotton, onion, spinach, carrot, grape, apple, pear
-Chinese centre; millet, soya, onion, cucumber, pear, peach, apricot, sugarcane, opium poppy
-Siam, Malaysia, Javan Centre; sugarcane, banana, breadfruit
-Indian centre; rice,beans, cucumber, radish, orange, sugarcane, banana
-Ethiopian centre; wheat, barley, sorghum, millet, coffee, okra
-S American centres; potato, maize, tomato, peanut, rubber tree, pepper, Brazil nut
-Central America centre; potato, maize, tomato, peanut, rubber tree, pepper, Brazil nut
Genetic resources; what is the disadvantage of Centres of Diversity?
Many of them in parts of the world where environmental degradation threatens survival of remaining wild plants
Genetic resources; what is a gene-pool and why may large populations not always have a large one?
-Total number of diff genes present in all individuals in a population of a particular species
-As they may all be descendants of closely related individuals so are all genetically similar
Genetic resources- gene-pool problems; why are domestic species often being produced from a very small number of original ancestors an issue?
-Lack wide variety of characteristics found in wild/traditional subsistence cultivars (varieties)
-If they’re genetically similar they’ll have similar adaptations & may all be susceptible to same environmental changes
-There’s also a greater risk of inbreeding where disadvantageous recessive genes could cause issues
Genetic resources- gene-pool problems; what does the desirability of a large gene-pool mean?
-Conserving few representatives of each species isn’t enough
-A wide range of genetically different, comparatively distantly-related individuals must be protected
Genetic resources- gene-pool problems; how and why do gene-pools differ due to geographical reasons + how can they be protected?
-Each region, within geographical range of particular species, is likely to have some genes unique to that area
-These will exist due to need to be adapted to the specific local conditions in each region
-So, to protect all genes in the gene pool, each species should be protected over its entire range, not just few convenient areas
Genetic resources- Ecosystem services; how is atmospheric composition influenced by ecosystem services?
-Composition of atmosphere is regulated by many abiotic & biotic processes that act to cancel each other out, creating a ‘dynamic equilibrium’
-As the processes may be balanced, w/ no overall change, their actions & importance often go unnoticed
-Eg, conc of CO² & O² are largely regulated by photosynthesis & aerobic respiration
Genetic resources- Ecosystem services; how is the hydrological cycle influenced by ecosystem services?
Evapotranspiration from vegetation produces large amount of water vapour that forms clouds, controls surface temp, ↑ precipitation
Genetic resources- Ecosystem services; how are biogeochemical cycles influenced by ecosystem services?
-Living organisms are involved in many processes in biogeochemical cycles like carbon, nitrogen, phosphorus cycles
-Many of these are done by microbes like bacteria & fungi
-W/out these processes, waste products would build up & important nutrient resources would become depleted
Genetic resources- Ecosystem services; how is soil maintenance influenced by ecosystem services?
-Soil= vital for growth & survival of almost all plants, providing support, water & nutrients. Also regulates water cycle, producing even more river flow &↓ flooding
-Processes involved in breakdown & decomposition of dead organic matter involves invertebrate animals, fungi & bacteria
-Organic matter & humus produced help hold soil together, while decomposition produces organic acids; aid weathering + breakdown of rocks, helping to produce more soil, release more nutrients
Genetic resources- Ecosystem services; how are interspecies relationships influenced by ecosystem services?
No species can live in ecological isolation as survival relies on other species for a range of resources & ecological services
Genetic resources- Ecosystem services; how is food influenced by ecosystem services?
All heterotrophs rely on other organisms as source of energy & nutrients
Genetic resources- Ecosystem services; how is pollination of flowers by insects influenced by ecosystem services?
-Allows plants to have dispersed populations as insects search over long distances for flowers
-Insect pollination is more successful than wind pollination; very unreliable over long distances
-Plants w/ insect-pollinated flowers save energy as they don’t need to produce as much pollen as wind-pollinated plants
-Many plants have evolved flowers that attract particular insects & many insects have evolved to be able to feed from flowers of particular species. -These specialisations give pollinating insects exclusive source of food, ↓ risk of pollen being carried to other plant species, eg Darwin’s Orchid in Madagascar w/ Sphinx Moth
Genetic resources- Ecosystem services; how is pollination of flowers by animals influenced by ecosystem services?
-Especially important in habitats like forests where trees ↓ wind velocity so wind pollination wouldn’t be effective
-Most animal species pollinating flowers are insects, especially bees but butterflies, moths, beetles & wasps are also important
-Other pollinators include some bird species, bats & monkeys. The animals visits the flowers to drink the sugar-rich nectar, picking up pollen when they do so
Genetic resources- Ecosystem services; how is seed dispersal by animals influenced by ecosystem services?
-Has many advantages over dispersal by wind as it’s not haphazard & seeds may be carried larger distances. Since animals live in same habitat as plant, they’re likely to carry seeds to locations where seeds can survive
-Seeds can also be larger, then carried by wind =↑ survival as seeds have more nutrients for growth of young plants made when seeds germinate
-Plants often attract animals using bright coloured fruit that tastes good
-Seeds may be dropped by animal/seeds may pass through animal’s gut & be carried to suitable having in faecal material; acts as a fertiliser. Seeds of many plant species are stimulated to germinate by their passage through intestines of animals that disperse them
Genetic resources- Ecosystem services; how is influenced by ecosystem services?
One species may provide habitats for other species;
-Tress provide nest sites for birds
-Hermit crabs live inside shells of dead molluscs
-Tress control abiotic conditions beneath canopy like light levels, humidity, wind velocity, temp—> may provide conditions suitable for species that can’t survive in more exposed locations
Threats to biodiversity- direct exploitation; how has food exploitation directly threatened biodiversity?
-Many species have been overexploited to provide food for humans, eg turtles, cod, swordfish, tuna, many herbivores
-Some species have become extinct, like the Dodo, Great Auk, Passenger Pigeon
Threats to biodiversity- direct exploitation; how has fashion exploitation directly threatened biodiversity?
Animal skins have been used for clothing throughout human history. However, certain animals have been over-exploited for fashion, eg;
-Fur coats & accessories; leopard, snow leopard, ocelot, tiger, fur seals (neatly hunted to extinction for their skins in late 1900s)
-Leather bags & shoes; crocodiles & alligators
-Feathers from kingfishers, parrots & ostriches
Threats to biodiversity- direct exploitation; how have pet and entertainment exploitation directly threatened biodiversity?
-Pets; parrots, lizards, snakes, tortoises, tropical fish
-House plants; ‘air plants’ (Tillandsia), some tropical exotics & many insectivorous plants are collected in wild to be sold
-Zoos; used to be common to collect wild animals for zoo collections. This is rarer now & normally only occurs for conservation reasons, like need to ↑ gene pool for captive breeding programme
-Aquaria; marine fish don’t breed well in captivity as required conditions aren’t understood. Most captive marine fish have been taken from the wild
-Marine life centres; many dolphins & orcas (killer whales) kept in captivity were caught in wild
Threats to biodiversity- direct exploitation; how has the exploitation of furniture & ornaments directly threatened biodiversity?
Many species have been selectively collected to make furniture/ornamental items;
-A lot of furniture’s made w/ timber from tropical rainforest trees like mahogany, teak, ramin
-Black piano keys were made w/ tropical ebony wood & white keys were made w/ elephant ivory
-Jewellery has been made w/ shark’s teeth, turtle shell, mollusc shells
-Coral & sea shells have been collected & sold as tourist souvenirs
Threats to biodiversity- direct exploitation; how and why has the exploitation of traditional medicines directly threatened biodiversity?
-Demand for traditional medicines, esp Asia, has led to large numbers of selected species being collected. There’s little scientific evidence they’re effective as medicines & ever if they were they may become unavailable as future pop. ↓. Many species are killed for traditional medicine trade;
-Tigers; diff parts are used in belief that they’ll cure many issues, eg claws as sedative, tail for skin disease, dung ter alcoholism, brain for laziness
-Rhinoceros; horn is used as supposed cure for many medical issues from nosebleeds to smallpox
-Seahorses; used to make medicines in belief they treat infertility, baldness, asthma, arthritis
Threats to biodiversity- direct exploitation; how has the exploitation of other products directly threatened biodiversity?
-Very fine oil was extracted from whale blubber & spermaceti from heads of Sperm Whales
-It was used until the 1970s in manufacture of products like lamp oil, candles, soap, lubricating oil, cosmetics, perfume.it has been replaced w/ oil from jojoba plant
Threats to biodiversity; why and how has the eradication of predators and competitors threatened biodiversity?
Many species have been killed as they threaten humans/interfere w/ human activities, eg;
-Animals which threaten animals, eg sharks, poisonous snakes & crocodiles
-Pathogen vectors, eg malaria mosquitoes, tsetse flies
-Predators of livestock, eg wolves, puma, lions, birds of pray, herons, seals
Agricultural pests, eg insects, fungi, birds, molluscs
-Wild herbivores that eat crops/compete w/ livestock, eg rabbits, deer
-Forestry pests, eg wood-boring beetles, deer, squirrels, beavers
Threats to biodiversity- changes in abiotic factors; what are the ways in which human activities have changed water availability + effects of this?
-Land drainage has affected large areas of wetland as land has been reclaimed & farmland has expanded
-Over-exploitation of groundwater resources can ↓ water table in ground → may cause surface wetland habitats to dry out, making it impossible for wetland species to survive
-Water level in tropical rivers may naturally rise & fall w/ wet & dry seasons
-Sandbanks & riverbanks exposed during dry season may be crucial nest site for birds, freshwater turtles & lizards
-Hydroelectric power schemes may cause sudden changes in water levels that flood nests, killing eggs
Threats to biodiversity- changes in abiotic factors; what are the ways in which human activities have changed dissolved oxygen levels + effects of this?
-Levels in water can be ↓ by hot water discharges from power stations/discharging organic wastes like sewage, which deoxygenates the water as it decomposes. ↓ in dissolved O² can ↓ survival of aerobic organisms like fish
-Marshland plants like sundew can be found in areas w/ waterlogged anaerobic soils where aren’t out-competed by taller plants. Anaerobic soils have ↓ nitrogen levels so large plants w/ high N requirement can’t live there
-Trapping & digesting insects provides sundews w/ source of N not present in nutrient-deficient soil
-Drainage schemes producing more aerobic soil may allow taller competitors to colonise area, causing sundew to die out
Threats to biodiversity- changes in abiotic factors; what are the ways in which human activities have changed temperatures + effects of this?
Can affect wildlife species in many ways. Growth/survival of some species will increase but others may not be adapted to survive change. Examples;
-Global climate change; temp changes will cause changes in distribution of species as no longer colonise areas which become suitable/die out in areas where they can no longer survive
-Hot effluent water; ↑ in water temp can ↑ growth of aquatic vegetation, providing more food for aquatic animals/may ↑ rate of decomposition, causing deoxygenation
Threats to biodiversity- changes in abiotic factors; what are the ways in which human activities have changed pH levels + effects of this?
-Mine drainage water & pollutant gases from burning fossil fuels/smelting metals can create acidic conditions
-These can denature cell proteins of exposed tissues
-Some organisms/tissues are particular vulnerable to acidic conditions like fish eggs & gills or invertebrates w/ calcium-based exoskeletons, eg crayfish
Threats to biodiversity- changes in abiotic factors; what are the ways in which human activities have changed water turbidity + effects of this?
-Activities like ploughing, mining, dredging may ↑ water turbidity
-This can ↓ light penetration & prevent submerged aquatic plants from photosynthesising
-Can also kill filter-feeding organisms like many bivalve molluscs whose gills become blocked
Threats to biodiversity- changes in abiotic factors; what are the ways in which human activities have caused physical damage?
Wide range of human actions can cause physical damage like discarding litter/old fishing gear
Threats to biodiversity- changes in biotic factors; how have human actions impacted pollination and what is the result of this?
-Use of pesticides & loss of wild flowering plants has ↓ populations of many insect species, including many bee species
-Many plants rely on pollen being transported betw their flowers by insects
It insects were to die out, plants wouldn’t be able to reproduce
Threats to biodiversity- changes in biotic factors; how have human actions impacted seed dispersal species and what is the result of this?
-Animals that eat seeds & fruit can be vital in successful dispersal of seeds & so future plant survival
-Many large herbivore species are endangered, eg elephants, rhinos, hippos, gorillas & many monkey species
-Conservation of these herbivores would help protect plant species relying on them
-Elephants diaper he seeds of most tree species where they’re found. Unlike most large mammal herbivores, they aren’t ruminants so don’t repeatedly chew their food (would destroy seeds). They’re also not territorial so would spread seeds over large areas than most herbivores
Threats to biodiversity- changes in biotic factors; how have human actions impacted food chains and what is the result of this?
-Decline in populations of some species has been caused by over-exploitation of their food by humans, like puffins which have ↓ as sandeels have been over-fished
-Over-exploitation of one species can cause ↑ of another. Eg, over-collection of turtle eggs has caused ↓ in turtle numbers & so ↑ in their food species, including jellyfish which eat zooplankton. So, their numbers have ↑ due to overfishing of competitor species which also eat zooplankton, eg sardines, herring, anchovies
-↓ in pop. of sea otters on west coast of USA caused ↑ in sea urchins they eat. Sea urchins over-grazed kelp seaweeds vital for survival of many species, incl sea otters
Threats to biodiversity- introduced species; what impact do introduced species have on ecosystems?
-Community of species naturally found in an area will be adapted to its abiotic & biotic surroundings
-If a species is introduced, it may have adaptations giving it a greater chance of survival than indigenous species, which may ↓or die out
-Many species’ introductions have had catastrophic effects on pop. of indigenous species. Pop. in isolated areas like islands have been have been v seriously affected; often have evolved from small number of OG colonising species & may not be adapted to survive new threats, eg mammal predators
Threats to biodiversity- introduced species; what are examples of introduced competitors and how have they been harmful?
-Grey squirrel was introduced to UK from N America. In many years, it has out-competed indigenous red squirrel as it’s better adapted to exploit available food; can digest acorns from oak trees which red squirrels can’t, is also larger & can compete more successfully for nest sites
-Rhododendrons were introduced to UK from Asia due to their ornamental flowers & as they provide cover for game birds like pheasants. They’re v invasive & being evergreen shade the ground + prevent regrowth of native vegetation. They also release toxins inhibiting growth of other plants
Threats to biodiversity- introduced species; what are examples of introduced predators and how have they been harmful?
-Range of European Water Vole in UK rivers has been ↓ by American Mink that escaped from fur farms
-Many species in Australia are threatened by Came Toads which were introduced from S America to control insect nests in sugar cane plantations. Toads didn’t control insect pests but became serious predators to others
-Ground nesting birds on many oceanic islands like New Zealand, Australia & Hawaii are threatened by introduction of cats, rats, pigs, dogs
-Introduction of cattle, sheep, pigs, goats, rabbits has had huge impact on vegetation & so wildlife communities relying on it. Impact is often greatest where there’s few indigenous herbivores, eg oceanic islands like Mauritius
-Nile Perch introduced into Lake Victoria to improve food supplies, but ate indigenous food species like cichlids, many of which are now extinct
Threats to biodiversity- introduced species; what are examples of introduced pathogens and how have they been harmful?
Humans may introduce pathogens, causing ↓ in wildlife pop. Pathogens are often carried by other species
-Grey Squirrel was introduced from N America to UK, brought squirrel pox virus, which doesn’t kill Grey Squirrel but doesn’t kill indigenous Red Squirrel
-White-Clawed Crayfish is indigenous to UK but its pop. has ↓ after intro of several non-indigenous cray fish species, eg Signal Crayfish from N America (Carries fungal pathogen crayfish plague, kills White-Clawed Crayfish)
-Many tree pathogens have been introduced into UK, include Dutch Elm Disease, Ash Dieback, Sudden Oak Dueath. Most tree pathogens were brought into UK on vegetation/in soil when plants were imported
Threats to biodiversity- introduced species; what are examples of introduced species that can hybridise and how have they been harmful?
-If any introduced species is very closely related to an indigenous species then cross-breeding may produce fertile hybrids
-Natural gene-pool will be changed by introduction of gene it wouldn’t normally contain
-Eg, Red deer is indigenous to UK but is threatened by hybridisation w/ introduced Sika Deer. The Wildcat pop. in Scotland is also threatened by hybridisation w/ domestic cats
Threats to biodiversity- introduced species; what are examples of a loss of species that control abiotic factors and why is this harmful?
-Some species change habitats & produce abiotic features that other species need for survival
-Eg, African Forest elephants create clearings & water-holes that many other species rely on for water. Beavers build dams, creating small lakes colonised by many aquatic species. If these species are lost, many other will decline
Threats to biodiversity- habitat destruction; how have human activities caused habitat destruction?
Human activities may have impacts that cause complete habitat destruction, usually due to land-use change, including;
-Deforestation
-Ploughing of grassland
-Reservoir creation
-Mineral extraction, esp open-cast mining
-Urban expansion
Setting conservation priorities; what are the questions asked when deciding the best strategies to conserve wildlife?
-What is the present day situation; species present, populations, current changes in abiotic factors?
-Which species should be conserved? The conservation of one species may be beneficial/harmful to other species
-What actions need to be taken to conserve desired species?
-Can the outcomes be accurately predicted?
-Can the impacts be monitored accurately?
Setting conservation priorities; what are the roles of the International Union for Conservation of Nature (IUCN)?
-Coordinating global data on biodiversity conservation
-Increasing understanding of the importance of biodiversity
-Deploying nature-based solutions to global challenges in climate, food, sustainable development
Setting conservation priorities; how are species in the IUCN categorised?
According to their vulnerability to extinction, known as the IUCN Red List;
-Extinct; no known individuals remain
-Extinct in the wild; only survive in captivity
-Critically endangered; extremely high risk of extinction in wild
-Endangered; high risk of extinction in wild
-Vulnerable; high risk of becoming endangered
-Near threatened; likely to become endangered in near future
-Least concern; at lowest risk of becoming endangered
-Data-deficient; insufficient information for species to be categorised
Setting conservation priorities- IUCN; what species was recategorised in 2016 and why?
Plains Zebra has been recategorised from Least Concern to Near Threatened due to its declining population, mainly due to habitat loss
Setting conservation priorities- IUCN; which species were recategorised in 2016 and why?
-Successful conservation of the Iberian Lynx has resulted in re-categorisation from Critically Endangered to Endangered; a captive breeding programme & protection of 2 areas of suitable habitat have allowed its pop. to treble in 15 years
-The Tiger remains in the endangered category, although 3/6 sub-species are critically endangered; its range continues to shrink
-The White-headed Vulture was Vulnerable, but has been re-categorised as Critically Endangered as population has ↓ due to poisoning & persecution
Setting conservation priorities- IUCN; which species were assessed in 2014 and why?
-There’s about 100 species of lemur, all endemic to the Madagascar island. Of these, 22 are Critically Endangered & 48 are Endangered; habitat loss & hunting for bushmeat are the major threats
-Population of Bearded Vulture/Lammergeier is ↑ in Europe but ↓ worldwide due to poisoning, competition for food & increasingly, collisions w/ power lines. It’s been re-categorised from Least Concern to Near Threatened
-Fregate Island Beetle of Fregate Island in the Indian Ocean was categorised as Threatened. A programme to eradicate rats from island has resulted in population ↑ so it’s been re-categorised as Vulnerable
Setting conservation priorities- IUCN; which species were assessed in 2013 and why?
-Okapi is only found in forests in the Democratic Republic of Congo. Its population has ↓ due to hunting, habitat loss & difficulties in carrying out conservation programmes in areas w/ military conflict. It’s been recategorised from Near Threatened to Endangered
-Kori Bustard lives in sub-Saharan Africa. Its population is ↓ due to hunting for food & traditional medicines, habitat loss, deaths due to collisions w/ power lines. It’s been re-categorised from Least Concern to Near Threatned
Setting conservation priorities- IUCN; how many species have been selected for categorisation and why is this number so small?
-Total of about 85,000 species have been assessed & categorised; a small proportion of the total number of species existing
-As categorising a species involves a great deal of research, it’s important to select species for categorisation carefully
Setting conservation priorities- IUCN; why are species in habitats under particular threat used as a criteria to select species for categorisation?
Their status may indicate the status of the rest of the community of species, like the decline of lemurs in Madagascar being used to predict decline of other species
Setting conservation priorities- IUCN; why are evolutionarily unique species used as a criteria to select species for categorisation?
-May be categorised, eg if there are few closely related species. EDGE species are ‘Evolutionary Distinct and Globally Endangered’
-They have few close relatives & are often the only surviving member of their genus + can be last surviving genus of their evolutionary family, eg Bactrian Camel, Pygmy Hippo, Northern Bald Ibis & Secretary Bird
Setting conservation priorities- IUCN; why are endemic species used as a criteria to select species for categorisation?
-Isn’t found in any other area, so if there’s a change in threats to its survival & it dies out locally, there will be no surviving populations elsewhere
-Many endemic species w/ smaller ranges are found on islands, eg Galapagos, Seychelles, Hawaii, Madagascar. These include Gozo Wall Lizard, Red Ruffed Lemur, Aldabra Giant Tortoise
Setting conservation priorities- IUCN; what are keystone species and why are they used as a criteria to select species for categorisation?
-Has important role in maintaining ecological structure of community
-Importance usually great compared w/ their low abundnce/pop. biomass
-Possible roles incl; predation of potentially dominant species, provision of food, seed dispersal or creation of structural features of habitat, eg Jaguar in S America help to balance mammalian jungle ecosystem w/ their consumption of 87 diff species of prey. Other eg; Grey Wolves, beavers
Setting conservation priorities- IUCN; how do African Forest Elephants have impacts on their habitats that benefit other species as a keystone species?
-Keep paths through forest open
-Spread seeds of most tree species
-Keep water holes open; provide other species w/ water & mineral nutrients. Many plant & animal species live in clearings but couldn’t live in dense forest
Setting conservation priorities- IUCN; what are flagship species and why are they used as a criteria to select species for categorisation?
-Have a high public profile
-Raising support to protect flagship species may have wide benefit for wildlife conservation in general. May incl species in same habitat that are likely to attract support themselves
-Tigers, elephants, Giant Pandas, Orang Utans are more likely to raise support than spiders, bats, fungi, or moths which may be just as ecologically important
Setting conservation priorities- IUCN; why is the degree of population dispersal used as a criteria to select species for categorisation?
-When global population of species is fragmented into number of isolated populations its important to ensure viable local populations are maintained
-Fragmentation of habitats may not reduce total habitat area by much but may produce populations that’ll each die out as they lack sufficient resources/have small gene pools + will suffer from inbreeding
-Where entire population of species is found in 1 area it may be vulnerable to any local change in conservation success
-Chimpanzees & gorillas are found in several countries but all Bonobos (Pygmy chimpanzees) live in the forests of a single country
Methods of conserving biodiversity 1: legislation/protocols- legal protection of habitats and species; what legislation does The Wildlife and Countryside Act, 1981 cover?
-Designated protected areas like Sites of Special Scientific Interest & Marine Conservation Zones
-Protection of wild birds & nests; most birds are protected except some ‘pest’ species & game birds that can be legally hunted
-Protection of mammal species, eg otters, Hazel Dormouse, Red Squirrel, badgers & their setts (tunnels)
-Uprooting of wind plants; generally illegal
-Bats; may not be disturbed & woodworm treatment chemicals that are used in roofs where bats are present mustn’t be toxic to bats
Methods of conserving biodiversity 1: legislation/protocols- legal protection of habitats and species; in what ways can the legal designation of protected areas protect habitats & species?
-Protection of species
-Protection of habitats
-Restrictions in activities within protected area
-Restrictions on activities outside protected area
-Management agreements betw landowner & designating organisation
-Access restrictions
-International cooperation
Methods of conserving biodiversity 1: legislation/protocols- legal protection of habitats and species; which protected areas in the UK are designated mainly for wildlife conservation?
-Site of Special Scientific Interest (SSI)
-National Nature Reserve (NNR)
-Special Area of Conservation (SAC)
-Special Protection Area (SPA)
-Natura 2000 sites (SACs & SPAs)
-Ramsar Sites
-Marine Nature Reserve (MNR)
-Local Nature Reserve (LNR)
-Marine Protected Area (MPA)
-Marine Conservation Zone (MCZ)
Methods of conserving biodiversity 1: legislation/protocols- trade controls; what are CITES and how are species grouped within it?
-The Convention on International Trade in Endangered Species
-Main international agreement regulating international trade in wildlife
Selected species are are grouped in lists called appendices;
-Appendix I; includes species threatened w/ extinction, so all international trade banned except movement for conservation breeding programmes, eg all great apes, all big cats, all rhinos, Blue Whale
-Appendix II; includes species that may be threatened w/ extinction if trade isn’t closely controlled. Trade is permitted from countries where species is relatively well protected so limited exploitation doesn’t threaten their survival, eg Honduras Mahogany, Common Hippopotamus, Green Iguana
Methods of conserving biodiversity 1: legislation/protocols- organisations which aim to achieve sustainable exploitation; what is the main aim of the International Whaling Commission (IWC) and why?
-To regulate & manage whaling
-Populations of many whale species had been so depleted that commercial whaling was banned in 1986 until time in future that populations have recovered enough to be able to withstand commercial whaling
Methods of conserving biodiversity 1: legislation/protocols- organisations which aim to achieve sustainable exploitation; how do the IWC conserve whale stocks to control whaling and ensure sustainable exploitation?
-Total protection for certain species
-Designation of whale sanctuaries
-Setting limits on numbers & sizes of whales that can be taken
-Protection of suckling mothers & their calves
-Carrying out research into whale biology & activities that threaten whales like ship strikes & entanglement w/ fishing nets
Methods of conserving biodiversity 1: legislation/protocols- organisations which aim to achieve sustainable exploitation; what kind of whaling does the IWC allow?
-‘Aboriginal substinence’; whaling permitted for cultural groups that have traditionally hunted whales fer food, eg Inuit (Eskimos) of Alaska that have a catch quota of about 55 bowhead whales each year. People of St Vincent & Grenadines in Carribean can kill about 2 humpback whales each year
-‘Special Permit Whaling’ or ‘Scientific Whaling’; involves killing of whales for scientific research. Japan has used this approach to justify its whaling but in 2014 the International Court of Justice declared its whaling programme wasn’t for research
-Commercial whaling; Iceland & Norway use IWC regulation to set own quota for commercial whaling.in 2014, they killed about 800 Fin & Minke Whales
Methods of conserving biodiversity 1: legislation/protocols- organisations which aim to achieve sustainable exploitation; what is the Common Fisheries Policy of the European Union (EU CFP) and its aim?
-Series of regulations that control fishing within territorial waters of European Union
-Aim is to ensure fishing & aquaculture are environmentally, economically & socially sustainable & that they provide a source of healthy food for EU citizens
Methods of conserving biodiversity 1: legislation/protocols- organisations which aim to achieve sustainable exploitation; what regulations does the Common Fisheries Policy of the European Union (EU CFP) typically cover?
Catch quotas to limit total mass that can be landed
-Size limits, so fewer small fish are killed & have a chance to grow
-Net mesh-size regulations that allow smaller fish to escape, survive & have the chance to grow larger + breed
-Limits on fishing effort, like maximum size of fishing boat/number of days fishing can take place
-Ban on discarding of unwanted fish
Methods of conserving biodiversity 1: legislation/protocols- organisations which aim to achieve sustainable exploitation; what are the aims of the International Tropical Trade Organisation (ITTO) and its limitation?
-Aims to encourage sustainable management of tropical forests
-In 1990, members agreed to strive for international trade of tropical timber from sustainably managed forests by 2000, w/out unsustainable exploitation
-But, there was little evidence of success by 2000 & this has continued to be the case
Methods of conserving biodiversity 2: Captive breeding & release programmes; what does ex-situ conservation involve and why may it be done instead of in situ?
-For some endangered species, in situ conservation (on-site conservation/conservation of genetic resources in natural populations of plant/animal species) won’t ensure their survival, so ex-situ may be required
-Involves conservation away from where they’d usually live & often involves breeding of species in captivity so some young produced can be released to boost wild population
Methods of conserving biodiversity 2: Captive breeding & release programmes; what are the factors that influence decisions about captive breeding & release programmes?
-Is the wild population threatened?
-Is there a genetically diverse captive population?
-Is in-situ conservation being successful?
-Is keeping a captive population realistic?
-Is release into the wild likely to be successful, now or in the future?
Methods of conserving biodiversity 2: Captive breeding & release programmes; why do habitat size requirements make it difficult for many species to be kept in captivity?
-Some species require such large habitats that they can’t be kept in captivity
-Often the case for large animals like whales
Methods of conserving biodiversity 2: Captive breeding & release programmes; why do food requirements make it difficult for many species to be kept in captivity?
-Some species have feeding requirements that can’t easily be provided
-For example, insectivorous bats, fish that eat plankton
Methods of conserving biodiversity 2: Captive breeding & release programmes; why do species interrelationships make it difficult for many species to be kept in captivity?
Some species have complicated species interrelationships like plants w/ symbiotic mycorrhizal root fungi relationships, plants w/ specific pollinators or Large Blue Butterfly that overwinters in ants’ nests
Methods of conserving biodiversity 2: Captive breeding & release programmes; why do financial constraints make it difficult for many species to be kept in captivity?
Keeping animals in zoos or plants in botanic gardens is expensive & there isn’t enough money available to keep all endangered species in captivity
Methods of conserving biodiversity 2: Captive breeding & release programmes; why have conditions for breeding meant that many species in captivity haven’t been able to breed successfully?
-For many species, precise timing of breeding is vital to ↑ survival chances of their young
-Breeding is often triggered by stimuli like day length, light level, temp, amount of food/stored body fat
-If these essential conditions aren’t known & aren’t provided, they won’t breed
Methods of conserving biodiversity 2: Captive breeding & release programmes; why have population interactions + breeding success meant that many species in captivity haven’t been able to breed successfully?
-In the wild, breeding pairs of many birds may choose isolation while non-breeding individuals live elsewhere
-In captivity, mixing of breeding & non-breeding individuals may cause conflict & reduce survival of eggs & chicks
-Some species breed most successfully if breeding adults are separate from other adults
-Some species breed most successfully if there’s a choice of possible partners but others pair for life
Methods of conserving biodiversity 2: Captive breeding & release programmes; why has breeding habitat meant that many species in captivity haven’t been able to breed successfully?
-Some species can only breed if they have a suitable habitat Ike one that includes a suitable site for courtship display, social grouping, area for hunting, or nest site
-For example, flamingos only breed in large groups. Mirrors around a captive population give the illusion of a larger population
Methods of conserving biodiversity 2: Captive breeding & release programmes; why has gene pool size meant that many species in captivity haven’t been able to breed successfully?
-Most captive breeding populations have small gene pools which ↑ risk of inbreeding
-Harmful recessive genes may be common in pop. but can only be ‘expressed’ in offspring if both parents carried gene & passed it on to offspring; most are rare so it’s unusual for both parents to carry unless closely related
-But in captive breeding programmes it’s often impossible to use individuals not closely related
-Eg Hawaiian goose became very rare due to hunting, habitat loss & introduced predators. Captive breeding programme has ↑ wild pop. but captive pop. started w/ just 7 individuals. Inbreeding made some goslings w/ thin, hair-like feathers; insulate poorly so survival can be low in cold temp
-‘Stud book’ can be used to keep records of family trees which helps to ensure breeding occurs in individuals as unrelated as possible. It’s usually used by zoo specialising in keeping that specific species
Methods of conserving biodiversity 2: Captive breeding & release programmes; what is hybridisation and why has it meant that many species in captivity haven’t been able to breed successfully?
-Species in wild includes individuals that naturally interbreed to make fertile offspring
-In captivity, individuals may inter-breed (hybridise) w/ closely related species/varieties that woudn’t have naturally met in wild; can be prevented if they can be kept apart but it’s an issue w/ plants where pollen can be carried betw plants by insects/wind
-Managers of early zoos didn’t get need to keep sub-species apart. Offspring made, by breeding betw populations that wouldn’t have naturally inter-bred, will have combo of characteristics not found from natural breeding; individuals probably have no conservation value
-If hybridisation occurs, offspring will be diff from wild pop. & may not be as well adapted for survival
-Lion species has 2 distinct sub-species; African Lion & Asiatic Lion
Methods of conserving biodiversity 2: Captive breeding & release programmes; what is cryopreservation and why does it increase breeding success?
-Storage of eggs, semen & embryos by freezing for future use in breeding programmes
-Can be transported long distances much more easily than moving parent animals
-Allows production of offspring w/out parents having to meet. Can also be stored for use in future, even many years after donor individual has died
Methods of conserving biodiversity 2: Captive breeding & release programmes; what is artificial insemination (AI) and why can it increase breeding success?
-Involves collection of semen from male & its insertion into a female to make offspring
-Semen can be stored for years so male could father offspring long after he died
Methods of conserving biodiversity 2: Captive breeding & release programmes; which issues occurring in breeding programmes involving natural mating does artificial insemination (AI) avoid?
-Animals may not like in same zoo & one would need to be transported; expensive & may be dangerous for animals
-Mating can be dangerous, causing injury/death, esp for larger animals like elephants & rhinos
-Potential partners may not accept each other. In the wild, males & females have space to avoid each other if they wish. Putting potential mates together can be dangerous
Methods of conserving biodiversity 2: Captive breeding & release programmes; why is embryo transfer used and how can it increase breeding success?
-Some mammal captive breeding populations have very few breeding females; slows rate at which offspring can be produced as duration of pregnancy can be long
-For some species, there may be a closely related species w/ larger number of females in captivity which can be used as surrogate mothers
Methods of conserving biodiversity 2: Captive breeding & release programmes; what are the main stages in embryo transfer?
-Female of endangered species, eg Bongo antelopes, is treated w/ hormones so she ovulates & releases large number of eggs
-Eggs are washed out of uterus & fertilised w/ sperm from male Bongo
-Each embryo is implanted into female of more common species, eg Common Eland antelopes. Pregnant Elands give birth to Bongo calves
-Female Bongo can produce many eggs on each ovulation & could do so during each oestrus cycle (every 3 weeks) rather than producing 1 calf per year
Methods of conserving biodiversity 2: Captive breeding & release programmes; what is micro-propagation of plants and how does it increase breeding success?
-Form of tissue culture where many clusters of cells can be made from a single plant/tissue sample
-Each cell cluster can be cultivated to produce individual plant
-In this way, many plants can be produced from single parent plant; all are genetically identical
Methods of conserving biodiversity 2: Captive breeding & release programmes; what does cloning involve and has it had any success in increasing breeding success in animals?
-Involves production of embryos by transferring nucleus from stem cell of endangered species into an empty egg cell of a closely related species
-Egg is implanted → female of closely-related species, eventually producing a baby animal of endangered species
-Has been used w/ limited success in livestock breeding but not yet w/ wild animal species; success rate v low so far. It’s possible deep frozen stem cells could be used to produce clones in if living population has died out
-Experiments are continuing & one day it may be possible to produce young from species that don’t currently breed, eg Northern White Rhinoceros
Methods of conserving biodiversity 2: Captive breeding & release programmes; why is cloning important in plants and what is an example of this?
-Important in some plant breeding programmes where cuttings of a mature plant can be cultivated to create many genetically identical plants
-Indigenous subspecies of Atlantic Black Poplar in UK is rare. Its future survival is threatened as their flowers can be pollinated by pollen of other introduced subspecies, making hybrid plants
-To maintain pure gene pool of the population, cloning is used to create many young plants that are genetically identical to non-hybrid parent plants
Methods of conserving biodiversity 2: Captive breeding & release programmes; what must successful release programmes provide?
-Large enough suitable habitat
-Reliable food supplies
-Low predation risk
-Suitable breeding sites
-Water
-Support of the local human population
-Official support, eg legal protection of the habitat & species
Methods of conserving biodiversity 2: Captive breeding & release programmes; what are the two types of for,s of release for individuals bred in captivity?
-Hard release; involves releasing individuals w/ no post-release support. Usually involves species where behaviour is controlled by instinct so individuals don’t need to learn survival skills, eg insects, fish, reptiles
-Soft release; involves post-release support like gradual release into larger areas & provision of food as they learn how to find food for themselves. Often necessamo for release of mammals & birds
Methods of conserving biodiversity 2: Captive breeding & release programmes; what are the problems faced by individuals bred in captivity?
-Finding & recognising food
-Recognising poisonous food
-Developing hunting skills; parents likely also bred in captivity so couldn’t teach their young & unlikely to learn in captivity w/ live prey
-Recognising & avoiding predators
-Being accepted into social groups of the wild populations
Methods of conserving biodiversity 2: Captive breeding & release programmes; what are seed banks and why are they used?
-Set up to store seeds of wild plants so species wouldn’t become globally extinct if became extinct in the wild
-If a species becomes rare in the wild, seeds stored in seed bank should maintain the biodiversity of species
Methods of conserving biodiversity 2: Captive breeding & release programmes; why are species selected for storage in a seed bank?
-Because they’re already threatened in the wild
-Because they’re of particular importance to humans, eg wild relatives of commercial crops
Methods of conserving biodiversity 2: Captive breeding & release programmes; what is the Millennium Seed Bank at Wakehurst Place in Sussex and how does it work?
-Major centre for the conservation of plant genetic diversity
-Seeds are collected from all over the world & stored under dry/refrigerated conditions
-Target number of seeds for each species is 10,000 to try to ensure diverse gene pool
To reduce risks of major accident, seeds are stored underground in a reinforced vault
Methods of conserving biodiversity 3: Habitat conservation; what are the 3 general approaches to habitat conservation?
-Land ownership
-Designated protected areas
-Habitat creation & management
Methods of conserving biodiversity 3: Habitat conservation; why does land ownership help habitat conservation?
-Many wildlife conservation organisations purchase areas to protect species that already live there/will do so once conditions have been changed so they’re suitable, eg RSPB, National Trust, Woodland Trust
-Individual landowners may also make management decisions for benefit of wildlife
Methods of conserving biodiversity 3: Habitat conservation; what are designated protected areas and why are they created?
-Designating a protected area establishes legal status of protection
-Owners of the habitat that needs protection may not wish to manage their land for benefit of wildlife in same way that statutory authorities do
-Establishing legally designated protected area should ensure habitat is protected
Methods of conserving biodiversity 3: Habitat conservation- designated protected areas; what are the key features of Sites of Special Scientific Interest (SSSIs)?
-Designated by UK legislation
-Protect areas w/ best examples of UK’s flora, fauna, geological/physiographical features
-Management plan is agreed w/ owner, who must inform gov conservation organisation if they wish to carry out an ‘OLD’; ‘Operation Likely to Damage’. -Vary betw sites but often include: ploughing, use of pesticides/fertilisers, drainage, burning, tree planting/removal
Methods of conserving biodiversity 3: Habitat conservation- designated protected areas; what are the key features of National Nature Reserves (NNRs)?
-Designated by UK legislation
-Best examples of SSSIs & usually cover best examples of complete communities of species/habitat types
Methods of conserving biodiversity 3: Habitat conservation- designated protected areas; what are the key features of Special Areas of Conservation (SACs)?
-Designated under EU Habitats Directive
-Each member state in EU must identify habitats within its country that are of international importance, than protect them
-Habitat types vary widely betw diff countries
-Designation may also restrict activities in surrounding areas, eg drainage
Methods of conserving biodiversity 3: Habitat conservation- designated protected areas; what are the key features of Special Protection Areas (SPAs)?
-Designated under EU Birds Directive
-Each member state in EU must identify places within its country that are of international importance for birds, then protect them
-Bird species involved vary widely betw diff countries
Methods of conserving biodiversity 3: Habitat conservation- designated protected areas; what are the key features of Ramsar sites?
-Ramsar convention is an intergovernmental agreement protecting wetlands -Most countries in the world are signatories
-Was originally intended primarily to protect important waterfowl habitats
-Convention has broadened its scope to cover all aspects of wetland conservation & wise use, recognising wetlands as ecosystems that are very important for biodiversity conservation in general & for well-being of human communities
Methods of conserving biodiversity 3: Habitat conservation; what do agri-environmental schemes recognise and why?
-Much of GB landscape (and its wildlife habitats) was produced by farming & can only be conserved by continuance of appropriate farming methods
-Increasingly intensive farming methods, esp since 1950s have caused a lot of damage, often removing habitats most important for wildlife, eg hedgerows & hay meadows/by using harmful pesticides. Changes were in response to need for ↑ food output for national food security
Methods of conserving biodiversity 3: Habitat conservation; what do agri-environmental schemes provide?
Financial support to farmers to reward & encourage environmentally beneficial developments
Methods of conserving biodiversity 3: Habitat conservation; what are examples of agri-environmental schemes that have been used?
-Environmentally Sensitive Areas (ESA)
-Countryside Stewardship Scheme (CSS)
-Environment Stewardship Scheme (ESS)
-Countryside Stewardship (CS)
Methods of conserving biodiversity 3: Habitat conservation; what are the aims of most agri-environmental schemes?
-Conserve wildlife (biodiversity)
-Maintain & enhance landscape qualify + character
-Protect historic environment
-Promote public access & understanding
-Protect natural resources
Methods of conserving biodiversity 3: Habitat conservation; what are the individual features of a farm with an environmentally beneficial management plan granted annual payments?
-Beetle banks; to provide habitats for natural predators & reduce pesticide use
-Hedgerow, store wall & ditch management; to maintain landscape features & wildlife habitats
-Field buffer strips; to protect rivers
-Wild bird seeds; to provide winter bird food
-Low input grasslands; to protect wildflowers
-Protected archaeological sites
-Management to reduce soil erosion; to maintain production & protect rivers
-Protection of in-field trees; as wildlife habitat & landscape feature
Methods of conserving biodiversity 3: Habitat conservation; what are the extra schemes made by organic farms/farms which receive higher payments?
-Wildlife-rich grass field margins
-Unharvested conservation field headlands for winter bird food
-Restoration of wet grassland for waders & wildfowl
-Water meadow restoration
-Maintenance/restoration of saltmarsh, sand dunes, hedgerows, moorland, traditional orchards, ponds, woodlands
-Public access
Methods of conserving biodiversity 3: Habitat conservation; what are the human activities that have unintentionally created habitats?
Reservoirs, flooded sand & gravel pits, roadside verges, hedgerows, ornamental gardens
Methods of conserving biodiversity 3: Habitat conservation; why is intentional habitat creation needed and what are examples of this?
-In-situ conservation will only be successful if there’s suitable habitats for species that’ll live there. These may already exist/may be necessary to alter & manage habitat currently unsuitable; requires understanding of abiotic & biotic habitat features that species require
-Habitats that have been created deliberately for wildlife conservation include wetlands, new woodlands, wildflower meadows & artificial coral reefs. Lakenheath & Wallasea Island RSPB reserves were both areas of arable farmland before habitat creation for wildlife began
Methods of conserving biodiversity 3: Habitat conservation- design; what are the requirements for habitat area when designing habitats?
-Must be large enough to support viable populations
-Breeding population mustn’t drop so low that reproduction rate is too low to maintain population & gene pool mustn’t be so small to cause inbreeding
-How large area is depends upon species. In general, species higher up food chains have lower population densities, so larger habitat area may be needed to support viable population. Eg, territory of single tiger can be upto 100 km² so large area is needed to support viable population
-Area too small to support populations of less abundant species, may eventually become unsuitable for other species if absent species provided important inter-species services. Eg, many rainforest monkeys eat fruit from trees. Diff tree species produce fruit at diff times of year, so food will always be available as long as forest area is large enough to have enough trees of sufficient range of species to support monkeys that eat fruit. A smaller area may lack some essential trees so there’d be time periods when there wouldn’t be enough food. If these periods are too long, monkeys may die out
-Some species benefit from small habitats. Frogs, toads & newts breed more successfully in ponds too small to support predatory fish that’d eat their eggs & tadpoles
Methods of conserving biodiversity 3: Habitat conservation- design; why are biological corridors important for habitat design?
-Linking isolated areas of same habitat type allows dispersal of young animals if there’s local breeding surplus & mixing of diff populations + gene pools which reduces risk of inbreeding
-If species dies out in one area, then re-colonisation from other areas is possible
-Can also be used to allow animals to avoid hazards when moving betw habitats
Methods of conserving biodiversity 3: Habitat conservation- design; why is habitat shape important for habitat design?
-Perimeter of a habitat will have a strip where the conditions are a combination of the two neighbouring habitats
-Some species benefit from these conditions, eg higher light levels at edge of a wood, but may not be suitable for species requiring core habitat conditions
Methods of conserving biodiversity 3: Habitat conservation- design; why is habitat diversity important for habitat design?
-Natural habitats are rarely uniform & usually have local variations in conditions, producing greater range of possible niches
-This increases biodiversity as different species colonise areas to which each is best adapted
Methods of conserving biodiversity 3: Habitat conservation- design; why are light levels important for habitat design?
-Shading effect of dense tree cover inhibits growth of plants on woodland floor
-This can be reduced by selectively felling individual trees to create suitable conditions for smaller plants that need more light
Methods of conserving biodiversity 3: Habitat conservation- design; why is water depth important for habitat design?
-Many plants & animals living in aquatic habitats will colonise areas w/ particular water depths
-Dominant plants= those that can absorb most sunlight, often by being taller
-Plants w/ emergent vegetation above water level can only support their weight in shallow water where roots can get a firm hold in the sediments
-As water depth increases, plant community changes as root anchorage & nutrient absorption from sediments becomes more difficult
-This explains plant community changes that happen in a hydrosere during ecological succession as water depth decreases
Methods of conserving biodiversity 3: Habitat conservation- design; why is vegetation age structure important for habitat design?
-Some habitats are dominated by plant species w/ individuals that can live for a long time eg woodlands where trees may live for hundreds of years
-A natural woodland will have trees of all ages w/ younger trees growing to fill the clearings created by the death of older trees
-In a recently planted woodland there will be few clearings until trees start to die of old age: could take 200+ years. During this time, the canopy will become v dense, light levels on ground would drop & biodiversity will decline, reducing wildlife value of woodland
-It’s not possible to plant n old woodland but is possible to create similar conditions by selective felling to create clearings & leaving dead wood to provide habitats for species that’d exploit old, dying & dead trees
Methods of conserving biodiversity 3: Habitat conservation- provision of abiotic habitat features; why are abiotic conditions important?
-Survival of species may depend on them
-If these are provided biodiversity of a habitat can be increased
Methods of conserving biodiversity 3: Habitat conservation- provision of abiotic habitat features; why is water important in a habitat?
Providing water, eg a pond, will allow birds + mammals to drink, amphibians to breed & provide a habitat for aquatic plants + animals
Methods of conserving biodiversity 3: Habitat conservation- provision of abiotic habitat features; why is dissolved oxygen important in a habitat?
-Lack of turbulence in slow moving rivers often creates low dissolved oxygen levels as less oxygen dissolves from air
-Making a river narrower will increase flow rates & turbulence which allows more oxygen to dissolve
-This creates suitable conditions for fish eg trout + insect species like mayfly larvae, both requiring high dissolved oxygen levels
Methods of conserving biodiversity 3: Habitat conservation- provision of abiotic habitat features; why is temperature important in a habitat?
-Warm temps are needed for the development of the eggs of many species
-Areas of shallow water warm up rapidly & allow the eggs of fish, newts, and frogs to develop more quickly
-Clearings where vegetation has been removed provide warmer areas of soil/sand where lizards may lay their eggs
Methods of conserving biodiversity 3: Habitat conservation- provision of abiotic habitat features; why are light levels important in a habitat?
-Most plants require specific light levels
-Creating clearings provides suitable conditions for the plants that need higher light levels, while retaining a dense canopy will provide shaded conditions needed by other species
-Light is essential for photosynthesis so energy can be captured & converted to chemical energy driving metabolic processes. Chlorophyll mainly absorbs red & blue wavelengths of light while most green light passes through
-Plants living under canopy vegetation in forests often have difficulty photosynthesising as chlorophyll in canopy has absorbed most red/blue light
-Forest floor plants often have additional pigments like anthocyanins & carotenoids which can absorb wavelengths of light that have passed through chlorophyll of canopy vegetation. These pigments also protect plants that live in bright sunlight from damaging UV lights & high light levels
Methods of conserving biodiversity 3: Habitat conservation- provision of abiotic habitat features; why is pH important in a habitat?
-Many plants can’t survive in acidic soils. May be because there are few nitrogen-fixing bacteria which make nitrates available for plant growth
-Those plants that can survive the acidic conditions may have few competitors, so even small plants can survive w/out being overshadowed by taller plants, eg sundew
-Many plants living in acidic, nitrate-deficient soils capture insects which they can digest to gain nitrogen nutrients
-A high/low pH can denature the proteins of the cells of exposed tissues like lungs, gills, root hairs. Low pH can inhibit production of calcium-based exoskeletons in organisms like crustaceans
Methods of conserving biodiversity 3: Habitat conservation- provision of abiotic habitat features; why are mineral nutrients important in a habitat?
- Some plants can live in nutrient-deficient soils where there’s less competition w/ taller plants for factors like light
-They may not be able to compete in areas w/ fertile soils so creation of a suitable habitat for these species may involve the removal of fertile topsoil/ not adding fertilisers
Methods of conserving biodiversity 3: Habitat conservation- provision of abiotic habitat features; why is salinity important in a habitat?
- Some aquatic species require water of a specific salinity, eg;
-The Opossum Shrimp is normally found in inter-tidal habitats which are more saline than freshwater but not as saline as seawater
-Controlling water salinity can increase opossum shrimp numbers & provide food for bird species, eg Dunlin & Pied Avocet
Methods of conserving biodiversity 3: Habitat conservation- control of biotic habitat features; how is the control of food important?
-Survival of an animal species may be increased if suitable conditions are provided for its food species, eg wildflower grasslands that support seed-eating birds
-Birds have different feeding methods to find food & avoid inter-species competition, eg honeycreepers eat nectar from flowers
Methods of conserving biodiversity 3: Habitat conservation- control of biotic habitat features; why is control of predation in habitats important + example?
-Will improve survival of animals, eg providing island breeding sites for nesting water birds that can’t be reached by terrestrial predators like foxes. If predators can’t be excluded, they may be trapped & removed/culled
-Introduced mammal predators are often a problem on islands which have no indigenous mammal predators, where colonies of ground-nesting birds become established
-Eradication programmes have been carried out on many islands. Eg, eradication of rats in Scilly Isles where 3000 rats were killed. Some of the islands are now free of rats & breeding success of birds like Manx shearwater & storm petrel have increased significantly
Methods of conserving biodiversity 3: Habitat conservation- control of biotic habitat features; why is control of competitors important in a habitat + example?
-The survival of a species may be increased if competitor species are controlled
-Eg, removing invasive rhododendron bushes allows wildflowers to grow as they aren’t outcompeted for light
Methods of conserving biodiversity 3: Habitat conservation- control of biotic habitat features; why is pollination in a habitat important?
-Many flowering plants need insects to pollinate their flowers so they can produce seeds
-They attract pollinators, eg bees, hover flies, wasps & butterflies using attractive flowers that produce sugar-rich nectar
-It may be necessary to have a range of other flowering plant species present w/ different flowering times so that insects have food available all through the seasons that they’re active
Methods of conserving biodiversity 3: Habitat conservation- control of biotic habitat features; why is seed dispersal in a habitat important?
Some animal species are important to plants for the dispersal of their seeds, eg hippopotamus, forest elephants, seed-eating birds, many monkey species
Methods of conserving biodiversity 3: Habitat conservation- control of biotic habitat features; why is control of pathogens in a habitat important?
-Disease is a density-dependent factor which can maintain health of surviving population by removing weakest individuals
-However, introduced diseases can wipe out indigenous species that have no resistance to them
Methods of conserving biodiversity 3: Habitat conservation- control of biotic habitat features; why are species re-introductions important in a habitat?
-Some habitats have been changed by human activities but still retain many of their original features
-It may be possible to restore the habitat by re-creating more natural conditions
-Many species will colonise these habitats naturally, esp more mobile species like flying insects & birds. Less mobile species may fail to colonise, may have to be reintroduced
-It’s particularly important to re-introduce any absent keystone species
Methods of conserving biodiversity 3: Habitat conservation- control of biotic habitat features; how has re-wilding in the Yellowstone National Park, USA been an example of species re-introduction and how has this caused ecological changes?
-The Gray Wolf was the top predator in the Yellowstone National Park in the Rocky Mountains, USA, but were exterminated by 1926
-This caused changes in the populations of other species
-Wolves have been reintroduced since 1995 & caused big ecological changes;
-Deer populations declined, so sever young trees killed
-More trees allowed beaver populations to increase
-Dams that beavers create have increased area of wetland habitats
-Wetland species have become more common; birds, fish, invertebrates
-Overall biodiversity increased but wolves have cause issues for nearby livestock farms
Methods of conserving biodiversity 3: Habitat conservation- control of biotic habitat features; how has re-wilding in Scotland been an example of species re-introduction?
-Most of Scotland used to be covered in a mixed forest incl pine, oak, birch, rowan trees. These were largely cleared for fuel & replaced w/ moorland grazed by sheep & deer
-Removal of grazing animals & reafforestation will allow recovery of populations of species like Capercaillie
-European beavers have been reintroduced & there are proposals to reintroduce Eurasian Lynx + grey Wolves, although very controversial
Methods of conserving biodiversity 3: Habitat conservation- control of biotic habitat features; what are examples of other species in the UK that have been re-introduced?
Red kite, White-tailed Eagle, Eurasian Otter, Common Crane, Great Bustard, Large Blue Butterfly
Methods of conserving biodiversity 3: Habitat conservation- control of biotic habitat features; how do abiotic factors which affect survival alter other species living in the same habitat in a forest?
-Tall foliage may cause reduced foliage
-Transpiration increases humidity
-Vegetation acts as windbreak & reduces wind velocity
-Decomposition of dead vegetation increases nutrient availability
Methods of conserving biodiversity 3: Habitat conservation- control of biotic habitat features; what are plagioclimax communities and why are they important
-In many areas, the activities that disturbed the climax community are carried out regularly so a new community of species develops
-Many are important for humans, eg grazed farmland, heathland & coppiced woodland. Are maintained as plagiomaxes for human use but are also colonised by wildlife species eg wildflowers living in hay meadows
Methods of conserving biodiversity 3: Habitat conservation- control of biotic habitat features; what could move the conditions of plagioclimaxes outside the range of tolerance of wildlife species living there?
The traditional human activities that produced the plagioclimaxes may change
Methods of conserving biodiversity 3: Habitat conservation- control of biotic habitat features; what do conservation programmes that aim to protect plagioclimax species involve?
-Continuing activities that traditionally maintained the plagioclimax
-Involves particular style of farming, eg hay meadows on Machair grassland on Outer Hebrides in Scotland & maintaining grazing marshes in The Broads National Park
Methods of conserving biodiversity 3: Habitat conservation- control of biotic habitat features; what is grazing and how do its different methods protect plagioclimaxes?
-Prevents establishment of taller plants & maintains grassland plagioclimax
-Conservation grazing is often used to maintain habitats eg chalk grassland & flower-rich meadows
-Trampling by livestock produces bare ground; important for germination of wildflower seeds + to produce warmer clearings needed by some invertebrates & reptiles
-Animal dung produces small areas w/ higher nutrient levels which may support different plant species & many invertebrates
-Diff grazing species are used for maintenance of diff plagioclimax habitats: sheep eat shorter grasses. Some breeds eat bushes; can be used to control invasive scrub, ponies selectively eat grass; usually avoid flowering plants but will eat invasive bracken which is avoided by most grazing animals & cattle are good for removing long, rough grass
Methods of conserving biodiversity 3: Habitat conservation- control of biotic habitat features; what is mowing and how is it similar/different to grazing? (plagioclimax protection)
Removes same vegetation that would be removed by grazing herbivores but it also removes the thorny, stinging, or bad-tasting plants that herbivores may have avoided
Methods of conserving biodiversity 3: Habitat conservation- control of biotic habitat features; what is burning and why is it used? (plagioclimax protection)
-Can be used to remove vegetation that wouldn’t be eaten by grazing animals, eg mature heather bushes & young trees on heathland
-It creates the open, unshelled areas needed for growth of young heather plants that’ll re-establish the heathland
-Heather seeds lie dormant in the soil until they’re stimulated to germinate by the heat of the fire
Methods of conserving biodiversity 3: Habitat conservation- control of biotic habitat features; what is coppicing and why is it done? (plagioclimax protection)
-Trees are cut to ground level every 3-30 years depending on the intended use of the harvested branches
-In many areas traditionally coppiced, about 0.5 ha was cleared each year w/ a rotational cycle of 8 years
-So, a coppiced woodland would be a patchwork of areas of woodland of diff ages, each suitable for its own community of wildlife species
Methods of conserving biodiversity 3: Habitat conservation- control of biotic habitat features; what is pollarding? (plagioclimax protection)
Similar to coppicing but w/ branches cut above height at which deer/livestock could eat the re-growing branches
Methods of conserving biodiversity 3: Habitat conservation- control of biotic habitat features; why is population control undertaken and how?
-It may be necessary to actively control populations of selected species by increasing/reducing them, depending on which species are desirable
-Release of captive-bred individuals will boost the wild population & help support population if size/breeding rate is low, or mortality rate is high
-Population of undesirable species may be controlled to reduce predation/competition
-The animals may be culled/trapped & removed
-Restoration & maintenance of a valuable wildlife habitat often involves removal of unwanted species. Some undesirable species may be a part of a natural ecological succession. Others may be invasive introduced species
-Conifer plantations are removed from the New Forest to re-establish heathland for Sand Lizards & Smooth Snakes
Selected habitats 1: Temperate broadleaf woodland; where are most temperate broadleaf woodlands and what are their trees like?
-In the northern hemisphere, Europe, eastern north America, east Asia
-Deciduous trees that lose their leaves each year
Selected habitats 1: Temperate broadleaf woodland; what are the dominant tree species in British broadleaf woodlands?
-Beech; on moist soils, eg clay
-Ash; on alkaline soils, eg limestone
-Oak; wide range of tolerance
Selected habitats 1: Temperate broadleaf woodland; what are the ecological features of temperate broadleaf woodlands?
-Don’t have major temp extremes
-No pronounced dry season; water available all year
-Soils usually deep & fertile. Trees play crucial part in soil formation w/ dead organic matter & its retention by vegetation cover + root binding
-Tree canopy layer is present from spring-autumn, so growth of plants under canopy is more difficult as are shaded during time when temps are best for growth. Many woodland floor plants overcome this by growing early in spring before trees have produced leaves, eg British Bluebells & snowdrops
-Lack of available food in winter causes many animals to become less active, store food, hibernate or migrate
Selected habitats 1: Temperate broadleaf woodland- importance; why is the high biodiversity of temperate broadleaf woodlands important?
-Creates a higher ecological stability
-No species are completely dominant so change in population of one species will have relatively small impact on overall community of species
Selected habitats 1: Temperate broadleaf woodland- importance; why are the woodland resources of temperate broadleaf woodlands important?
-Historically important for wide range of resources. Wood used for:
-Building construction; timber frames, wattle, daub panels
-Fencing
-Tools
-Carts
-Wood fuel
-Charcoal for metal smelting
Selected habitats 1: Temperate broadleaf woodland- importance; how are temperate broadleaf woodlands important for recreation?
Many used for walking, camping, cycling, picnics, etc
Selected habitats 1: Temperate broadleaf woodland- importance; how are temperate broadleaf woodlands important for the hydrological cycle?
All trees play role in the hydrological cycle through interception, evapotranspiration, control of water in soil
Selected habitats 1: Temperate broadleaf woodland- importance; how are temperate broadleaf woodlands important for carbon sequestration?
-All plants absorb CO² during photosynthesis but most release it again during respiration & decay of their vegetation
-Plants w/ woody tissue can build up a store of carbon in cellulose & lignin that forms wood, so woodlands are large reservoirs of stored carbon which reduces atmospheric carbon dioxide concentrations
Selected habitats 1: Temperate broadleaf woodland- threats; how has woodland clearance posed a threat to temperate broadleaf woodlands?
As societies have developed & populations have grown, natural woodland habitats have been cleared to provide space for new land uses:
-Farmland
-Plantations of single specieskon-indigenous species
-Urban developments
-Transportation infrastructure, eg new roads
-Mineral extraction
Selected habitats 1: Temperate broadleaf woodland- threats; how has habitat fragmentation posed a threat to temperate broadleaf woodlands?
-Woodland clearance may leave remaining areas that are isolated from each other
-If animals can’t move betw these areas, then each separate population becomes more vulnerable to extinction
Selected habitats 1: Temperate broadleaf woodland- conservation efforts; what have been the historical woodland management methods used for temperate broadleaf woodlands?
-‘Wildwood’; areas w/ virtually no interference, eg hunting forests
-Mature ‘standard’ trees; eg oak for timber-framed houses, furniture & ships
-Coppiced woodland; eg hazel for fencing, wall panels, oak for charcoal, pit props & tannins for leather tanning
-Pollarding; similar to coppicing but cutting was carried out at a greater height to reduce problem of animals eating re-growing branches
Selected habitats 1: Temperate broadleaf woodland- conservation efforts; what have been the modern woodland management methods used for temperate broadleaf woodlands?
-Monoculture plantations of single-age trees which have low wildlife value
-New woodland areas around field margins
-Community forests planted for recreational & amenity use
Selected habitats 1: Temperate broadleaf woodland- conservation efforts; what have been the conservation management methods used for temperate broadleaf woodlands?
-Coppicing to create wildlife habitats
-Creation of woodland clearings to increase habitat diversity
-Planting of mixed-species woodlands to increase biodiversity
Selected habitats 1: Temperate broadleaf woodland- conservation efforts; what are ancient woodlands and why are they protected?
-One that’s existed before 1600; few deliberately planted then so wood that’s 400+ is likely to have developed naturally a long time ago
-Some species of wild plant colonise woodlands very slowly, so their presence is evidence that the woodland is ancient
-Usually has very high biodiversity as there’s been a long time-period for species to colonise
Selected habitats 1: Temperate broadleaf woodland- conservation efforts; what are examples of designated protected areas?
-Sherwood Forest National Nature Reserve
-Epping Forest SAC
-Many woodland SSSIs
-Many UK National Parks have areas of deciduous woodland
-2012 National Planning Policy Framework states ‘planning permission should be refused for development resulting in loss/deterioration of irreplaceable habitats, incl ancient woodland & the loss of aged/veteran trees found outside ancient woodland, unless the need for, and benefits of development in that location clearly outweigh loss.’
Selected habitats 1: Temperate broadleaf woodland- conservation efforts; why have new woodlands been planted and how?
-Large areas of new woodland have been planted in UK over the past 30yrs, usually on small areas of farmland
-Have often incl mix of indigenous tree species likely to have increasing wildlife value as woodlands mature
-Are esp valuable if join existing areas of woodland/habitats eg hedgerows; can act as biological corridors linking small fragmented areas of woodland
Selected habitats 2: Tropical rainforest; what are the general features of tropical rainforests?
-Most diverse terrestrial ecosystems
-Not fully researched but relative ease w/ which new species can be discovered suggests over 1/2 of all terrestrial species live in tropical rainforests although rainforests only cover about 10% of Earth’s land area
Selected habitats 2: Tropical rainforest- ecological features; what is the climate like in tropical rainforests and how has this affected it?
-Has been relatively stable over long time periods, compared w/ regions further away from equator; has given rainforest species a long time to evolve & become adapted to local abiotic + biotic factors
-Has produced huge number of different species although many are relatively rare & have small ranges
-Being adapted to relatively stable conditions can make species vulnerable to extinction as small change in environmental conditions may move them outside their range of tolerance
-Migratory species found in tropical rainforests have normally come from other areas that have fluctuating conditions & have migrated to rainforests as they’re so stable
Selected habitats 2: Tropical rainforest- ecological features; what are light levels like in tropical rainforests and how has this affected them?
-High light levels; allow photosynthesis rates to be high, providing a lot of food energy to support a rich food
-There’s a lot of competition for light. Plants that have evolved to grow a tall trunk will have better access to light but must invest a lot of energy over long time to produce wood that forms the trunk. Smaller plants may need to evolve methods of utilising lower light levels, eg denser chlorophyll/additional pigments to absorb wavelengths of light that pass through leaves of taller plants
-Plants that are epiphytes & live on higher branches of trees have greater access to light w/out being tall but may have less reliable water + nutrient supplies
Selected habitats 2: Tropical rainforest- ecological features; what is the temperature and rainfall like in tropical rainforests and what has this allowed?
-Constant warm temperatures + regular high rainfall; allow plants to grow throughout year w/out seasonal changes that occur in higher latitudes
-Ensures reliable food supplies are available to animals throughout year. Populations rarely have seasonal fluctuations found in higher latitudes & there’s no need to hibernate/migrate to more favourable areas
Selected habitats 2: Tropical rainforest- ecological features; what is the main survival pressure in tropical rainforests produced by and why?
-Biotic factors; getting food, avoiding being eaten, & evolving better inter-species relationships
-As the abiotic conditions have been relatively stable for a long time, don’t fluctuate seasonally, there’s probably little need for most species to evolve further & become better adapted to abiotic factors
Selected habitats 2: Tropical rainforest- ecological features; how do tropical rainforests having no distinct season affect them?
-Different plant species don’t have to flower/produce seeds & fruit at the same times as each other
-So plants have less competition for services of animals to pollinate flowers/spread seeds
-Food in the form of nectar, seeds, or fruit is available to animals throughout year, which increases animal survival
Selected habitats 2: Tropical rainforest- ecological features; why are the deciduous trees in tropical rainforests important?
-Shed leaves every year but different species do so at different times of year
-So animals that feed on vegetation don’t have long periods when there’s no food, as is the case in temperate broadleaf woodlands
Selected habitats 2: Tropical rainforest- ecological features importance; why is the high biodiversity of tropical rainforests important?
Increases chances of finding species useful to humans, eg new food species, medical discoveries, biomimetic applications
Selected habitats 2: Tropical rainforest- ecological features importance; how do plants and animals produce medicinally useful chemicals
-No cold winters to kill off herbivores, so plants need to protect themselves from being eaten. Often done by producing toxic chemicals eg alkaloids that may have medicinal value for humans
-Animals produce medicinally valuable chemicals to avoid predation, esp those that can’t protect themselves w/ teeth/clawes or those that use venom to catch prey
-So, taxa like frogs & reptiles are much more likely to produce medicinally useful chemicals than mammals/birds
Selected habitats 2: Tropical rainforest- ecological features importance; what are the uses of the timber resources from tropical rainforests?
House construction, furniture, tools
Selected habitats 2: Tropical rainforest- ecological features importance; what are the uses of the fibre resources from tropical rainforests?
-Cotton
-Hemp; rope
-Raffia; rope & baskets
-Cellulose; rayon
Selected habitats 2: Tropical rainforest- ecological features importance; what are the uses of the resin, oil and wax resources from tropical rainforests?
-Rubber; latex gloves & vehicle tyres
-Carnuba wax; floor & car polish + confectionery coating
-Palm oil; processed foods, cooking oil & biofuels
Selected habitats 2: Tropical rainforest- ecological features importance; what are the uses of the food resources from tropical rainforests?
-Chocolate from cacao
-Pineapples, lemons, Brazil nuts, vanilla, coffee, bananas, oranges
-Spices; pepper, turmeric & cinnamon
-Bushmeat
-New food species
-Genetic resources for crop breeding
Selected habitats 2: Tropical rainforest- ecological features importance; what are the uses of the medicine resources from tropical rainforests?
-Cinchona trees produce quinine, used to prevent malaria
-Mexican wild yams produce diosgenin, used to make medicines eg cortisone to treat arthritis & asthma
-Curare lianas make d-turbocuarine, used to treat multiple sclerosis & Parkinson’s disease + used in anaesthesia
Selected habitats 2: Tropical rainforest- ecological features importance; how are tropical rainforests important for climate maintenance?
-Very important for increasing downwind rainfall
-1/2+ rainfall in Amazon rainforest results from transpiration elsewhere in forest rather than directly from evaporation of seawater
-As w/ temperate broadleaf woodland & all trees, carbon sequestration by photosynthesis stores large amounts of carbon in tropical rainforests; helps to reduce natural greenhouse effect
Selected habitats 2: Tropical rainforest- ecological features importance; how are tropical rainforests important for soil maintenance?
-Warm, moist conditions make dead vegetation decay very rapidly so nutrients can be re-absorbed by trees very quickly
-Due to this, soils in tropical rainforests are often very shallow
-Vegetation cover & roots are important in preventing soil that’s present from being eroded, as foliage protects it from heavy rain + roots hold soil together
-Forest clearance can lead to serious soil erosion
Selected habitats 2: Tropical rainforest- threats; how is fuelwood collection a threat to tropical rainforests?
-Wood = most important domestic fuel in rural areas of LEDCs
-Rate of wood collection → usually faster than rate of re-planting & natural re-growth
Selected habitats 2: Tropical rainforest- threats; how is timber harvesting a threat to tropical rainforests?
Two main uses;
-Use in country of origin for house construction & furniture
-Export to MEDCs for use in products eg furniture, doors, windows, decking & plywood
Selected habitats 2: Tropical rainforest- threats; how is clearance for subsistence agriculture a threat to tropical rainforests?
-‘Slash and burn’ or ‘shifting field’ agriculture has been carried out in rainforests for hundreds of years & generally caused few environmental issues
-Small clearings were made by felling trees to create area that could be farmed by a family → would be farmed few years then abandoned as soil nutrients were depleted & forest regrowth reclaimed clearing
-This agriculture is sustainable as long as there’s enough time for forest to recolonise area & soil fertility to recover before clearing again
-If population density is too high, time gap betw area being abandoned & cleared again will be too short so forest wouldn’t have recolonised fully + soil not regained fertility; family could farm area for as long as prev. If this continues, forest will be degraded + soil fertility will fall
Selected habitats 2: Tropical rainforest- threats; how is clearance for commercial agriculture a threat to tropical rainforests?
-As human populations grow, demand for farmland increases & habitats like rainforests may be cleared
-Rainforest clearance for cash crops & cattle ranching is often unsustainable, as poor tropical soils may become infertile + fail to provide high yields indefinitely
-If land is abandoned, it may be difficult for forest to re-colonise if there’s no surviving forest areas nearby from which species could recolonise
-Large areas of rainforest have been cleared for commercial cultivation of cash crops mainly for export eg, palm oil plantations in SE Asia, soya bean production in Brazil & coffee plantations in Vietnam
Selected habitats 2: Tropical rainforest- threats; how is mineral extraction a threat to tropical rainforests?
-There are many valuable deposits of metal minerals present under tropical rainforests, incl aluminium, iron, gold, silver & copper
-Extraction results in habitat loss & can cause water pollution when mineral is processed, eg discharges of turbid drainage water, cyanide & mercury
Selected habitats 2: Tropical rainforest- threats; how are reservoirs a threat to tropical rainforests?
-New HEP schemes can flood large areas of forest + create barrier to mobile species eg migratory fish & river dolphins
-Reservoir of Tucurui HEP scheme in Brazil covers area of 2850 km² -Decomposition of dead organic matter in deep, static, reservoir water can produce acidic, deoxygenated water that may be harmful to aquatic life downstream
-Flow of water out of reservoir may be controlled to generate electricity to match demand but fluctuating river levels downstream can affect wildlife
Selected habitats 2: Tropical rainforest- threats; how is climate change a threat to tropical rainforests?
-Temp rise caused by climate change may directly affect survival of some species & wind + precipitation patterns
-Droughts in tropical rainforests caused by climate change will increase number of forest fires & area fires cover. Fires are also likely to last longer, causing more severe damage. A short fire may just burn off dead vegetation & leaf litter, but long fire may boil tree sap + kill trees
-Populations of many frogs & toads in cloud rainforest are declining, in countries like Costa Rica
-Rising temps are reducing condensation & clouds are forming higher up mountains which reduces area of habitat that’s sufficiently humid for them to survive
-Epiphytic plants eg orchids & air plants absorb water from bark surface of the trees they live on. Their populations decline if air is less humid
-Some computer climate models predict that some rainforest areas will be replaced by savannah grassland
Selected habitats 2: Tropical rainforest- threats; how is tourism a threat to tropical rainforests?
-As w/ any developments, an expansion of tourism facilities can threaten habitats & wildlife
-Ecotourism is an increasingly important way of generating income w/out having to destroy the forest. However, in some countries the large numbers of visitors can cause damage as found in Costa Rica & Malaysia
Selected habitats 2: Tropical rainforest- conservation efforts; how have conservation efforts in Cameroon helped to conserve tropical rainforest?
-Korup National Park in Cameroon, Africa, was set up in 1986 & protects 1,260 km² of tropical rainforest
-It’s one of the least disturbed rainforests in Africa & retains very high biodiversity, incl many species of importance to humans
-There are 600+ tree species, 1000 butterfly species & 160 mammal species, many of which are endemic
-The plant Ancistrocladus korupensis was discovered in the Korup & has been found nowhere else; produces alkaloid chemicals of medicinal value, incl Michellamine B, which is being researched as a treatment for HIV & Korupensamine E, a new antimalarial drug
Selected habitats 2: Tropical rainforest- conservation efforts; how have conservation efforts in Brazil helped to conserve tropical rainforest?
-In 2014 the new Alto Maues reserve was established to protect 6,680 km² of rainforest. It’s home to 600+ species of birds & at least 13 primates species
-In 2002, the Tumucumaque National Park was established to protect 39,000 km² of rainforest; nearly x2 area of Wales, makes it the largest rainforest reserve in the world. It’s next to a rainforest reserve in French Guiana, giving a total protected area of 59,000 km²
Selected habitats 2: Tropical rainforest- conservation efforts; how have conservation efforts in Belize helped to conserve tropical rainforest?
-Rio Bravo Conservation & Management Area in Belize, Central America, covers 100,000 hectares of rainforest + associated habitats
-First established in 1988, it’s been funded by conservation charities in USA & Europe, w/ donations from companies like Coca Cola + electricity companies in USA & Canada. Money is also raised via ecotourism projects
-Sustainable exploitation of high value timber from trees eg mahogany also helps to pay for forest conservation; done by selective logging which doesn’t cause long-term damage to forest
Selected habitats 2: Tropical rainforest- conservation efforts; what are debt for nature swaps and how have they helped converse rainforests?
-Many countries w/ threatened rainforests are in debt to other countries, w/ little realistic chance of being able to pay it all back
-Country that lent money may be prepared to cancel debt in return for partial repayment/guarantee that an area of the rainforest will be protected
-USA has cancelled debts of $24m owed by Guatemala & $21m by Brazil
-Sometimes an intermediary organisation eg a conservation charity may negotiate to pay off part of debt in return for balance of debt being cancelled. The country that has had its debt cancelled agrees to conserve a wildlife habitat
-WWF has organized debt for nature swaps in this way to protect rainforests in Costa Rica & Philippines
Selected habitats 3: Tropical coral reefs; how do tropical coral reefs contribute to a high biomass of life thriving
-Water in tropical seas is often deficient in nutrients so biological productivity may low
-However, animals forming coral reefs have inter-species relationships that use nutrients very efficiently & allow high biomass of life to thrive
Selected habitats 3: Tropical coral reefs; what phylum do corals belong to?
Cnidaria; made up of 10,000+ species including jellyfish
Selected habitats 3: Tropical coral reefs- coral nutrition; what are cilia and how are they a source of nutrition for corals?
Finger-like projections on coral polyp tentacles which trap planktonic items floating past polyp which are then passed down to the stomach where they’re digested
Selected habitats 3: Tropical coral reefs- coral nutrition; what are nematocysts and how are they a source of nutrition for corals?
-Stinging cells that harpoon planktonic organisms floating past polyp
-These are then carried by the cilia to the stomach
Selected habitats 3: Tropical coral reefs- coral nutrition; what are symbiotic algae are and how are they a source of nutrition for corals?
-Zooxanthellae= photosynthetic algae that live inside coral polyp cells. They absorb sunlight & provide food energy for themselves + coral polyps
-The polyps & algae have an efficient method of recycling nutrients. CO² & excretory waste products produced by polyp are absorbed directy by algae for photosynthesis + growth. The algae produce oxygen & glucose which coral polyps need
-Coral polyps gain 95%+ of their food energy from this symbiotic relationship. In return, algae have a protected habitat & supply of nutrients they need
-Much of CO² produced by respiration of polyps is used by algae for photosynthesis. Surplus CO² is incorporated into calcium carbonate that forms coral. Other wastes from polyps provide nutrients needed by algae which they may not have been able to absorb from nutrient-deficient seawater
Selected habitats 3: Tropical coral reefs- reef building corals; how do tropical coral reefs contribute to reef building and why is this beneficial?
-Many species of corals secrete a limestone base which is continually added to, building up into a reef
-Other cnidarians like sea fans & soft corals don’t produce a hard skeleton so they don’t add to the reef
-Physical structure of reefs also provides many places for animals to live, as well as being a rich source of food that supports a complex food web
Selected habitats 3: Tropical coral reefs- abiotic conditions; what makes tropical coral reefs vulnerable to environmental change?
Are only found where there are very specific abiotic conditions
Selected habitats 3: Tropical coral reefs- abiotic conditions; how does light have an impact on tropical coral reefs?
-Symbiotic algae within coral polyps require bright sunlight
-In the tropics, there is bright sunlight in shallow water for about 12hrs almost every day
Selected habitats 3: Tropical coral reefs- abiotic conditions; how does temperature have an impact on tropical coral reefs?
Must be warm and constant, in the range 25-29°C
Selected habitats 3: Tropical coral reefs- abiotic conditions; how does immersion have an impact on tropical coral reefs?
-Polyps must be covered in water almost all the time to prevent them drying out
-They can’t live in deep water as not enough light would reach them for algal photosynthesis
-Many coral reefs are found where tidal range is small so can live near water surface w/out being uncovered at low tide
Selected habitats 3: Tropical coral reefs- abiotic conditions; how does turbidity have an impact on tropical coral reefs?
-Seawater must have very low turbidity
-Turbid water reduces light penetration so photosynthesis would be reduced
-Suspended solids carried by water could also settle on reef, sticking to the cilia & blocking the entrance to the stomach
-Survival of coral reefs often relies on mangrove forests & seagrass beds that trap eroded soil washed off land + prevent it settling on reefs
Selected habitats 3: Tropical coral reefs- abiotic conditions; how does salinity have an impact on tropical coral reefs?
-Coral polyps don’t have the ability to regulate water conc within their cells
-If salinity of the water changed outside narrow range of tolerance of corals, cells would be killed by osmosis w/ water flowing into/out of cells
Selected habitats 3: Tropical coral reefs- importance; why are tropical coral reefs ecologically important despite only covering about 1% of ocean area?
-Support 1/4+ of all marine species
-Provide valuable resources & help resist damaging environmental changes
Selected habitats 3: Tropical coral reefs- importance; why are tropical coral reefs important for fisheries?
Support many species exploited for food, including fish, crustaceans like lobsters and molluscs such as conch
Selected habitats 3: Tropical coral reefs- importance; why are tropical coral reefs important for medicinal discoveries?
-Many species that live on coral reefs don’t have spines, teeth or a hard shell to protect themselves
-Instead, they may produce toxic chemicals which may be useful as medicines when used in carefully controlled amounts
Selected habitats 3: Tropical coral reefs- medicinal importance; what are the medicinal uses of the chemicals in sponges from a coral reef in the Caribbean Sea?
-Antiviral drug AZT; used to treat HIV/AIDS
-Ara-C is used to treat leukaemia
Selected habitats 3: Tropical coral reefs- medicinal importance; what are the medicinal uses of the chemicals in sea hare (mollusc) on coral reefs in the Indian Ocean?
Dolastatin 10; inhibits cell division, has been tested as a treatment for cancer & malaria
Selected habitats 3: Tropical coral reefs- medicinal importance; what are secosteroids and their medicinal uses?
-Enzymes used by corals to protect themselves from disease
-Used to treat asthma, arthritis & other inflammatory disorders
Selected habitats 3: Tropical coral reefs- medicinal importance; what is bugula neritina and its medicinal uses?
-A bryozoan colonial marine animal
-Compound bryostatin 1; used to treat range of cancers, eg lung & prostate gland. It’s used in combo w/ other medicines, eg vincristine from tropical plant
-Also improves memory & is being researched as treatment for Alzheimer’s disease
Selected habitats 3: Tropical coral reefs- medicinal importance; what are the medicinal uses of species of sea squirt?
-Trabectedin is used to treat the cancer soft-tissue sarcoma
-Was discovered in a sea squirt but is now manufactured from similar chemical made by a bacterium
Selected habitats 3: Tropical coral reefs- medicinal importance; what are the medicinal uses of coral?
Used to make bone grafts for patients w/ diseases that cause bone deterioration
Selected habitats 3: Tropical coral reefs- importance; why are tropical coral reefs important for climate control?
-Reef-forming corals deposit a skeleton of coral w/ each polyp sitting in a coral cup
-Coral is made mainly of the mineral calcite, made of calcium carbonate w/ some magnesium carbonate. Each carbonate molecule requires absorption of a molecule of CO² , so growing coral reefs are a crucial carbon sink, helping to resist climate change
Selected habitats 3: Tropical coral reefs- importance; why are tropical coral reefs important for erosion protection?
-Many tropical islands are formed by fragments of coral, producing low-lying sand islands
-Coral reefs absorb energy of waves that would otherwise have eroded/washed away these islands
-The irregular shapes & complex structure of coral dissipate energy of waves effectively
-Fragments of coral form sand which helps build up shores
Selected habitats 3: Tropical coral reefs- importance; why are tropical coral reefs important for tourism?
Coastal areas & islands w/ coral reefs are popular tourist destinations for ecotourism activities eg scuba diving & snorkelling, + simple relaxation in pleasant surroundings
Selected habitats 3: Tropical coral reefs- threats; how is physical damage a threat to tropical coral reefs?
-Hard objects can kill polyps as are pushed against hard limestone beneath living cells
-Litter like floating bottles, lost fishing gear, boat anchors, & careless divers can all damage reefs
-Damage is also caused by extraction of coral for land reclamation & construction
Selected habitats 3: Tropical coral reefs- threats; how is the collection of ornaments & souvenirs a threat to tropical coral reefs and how is this reduced?
-Many species from coral reefs are collected to be sold as ornaments like mollus shells, hard corals, & sea fans
-Trade in about 2000 species of coral is restricted by CITES Appendix II
Selected habitats 3: Tropical coral reefs- threats; how is sedimentation a threat to tropical coral reefs?
Turbid water carried by rivers/sediments disturbed by coastal developments can cover & kill corals
Selected habitats 3: Tropical coral reefs- threats; how is pollution a threat to tropical coral reefs?
-Wide range of pollutants can harm coral reefs
-Large oil spills can cover coral reefs. Even at lower conc oil is toxic to corals
-Nutrients eg nitrates & phosphates from agricultural runoff + sewage effluents can stimulate growth of algae that cover corals. Shading caused by algae reduces growth of symbiotic algae within polyps & prevents release of eggs when corals reproduce
-Ocean acidification is caused by increased CO² conc in atmosphere. More CO² dissolves in oceans producing carbonic acid which makes the oceans more acidic, it’s therefore difficult for coral polyps to produce their coral skeleton
Selected habitats 3: Tropical coral reefs- threats; how is coral bleaching a threat to tropical coral reefs?
-Occurs when symbiotic algae within coral polyps are expelled
-Bleached corals look pale, hence the term ‘bleaching’. This can be caused by a variety of natural & anthropogenic factors
-One natural factor is raised light levels caused by increased solar activity, but many human activities can cause bleaching; Increased water temps caused by global climate change, low O² levels due to high zooplankton activity due to overfishing of their fish predators & pollution including sewage, pesticides, cyanide & sunscreen products
-Bleached coral polyps, which aren’t dead & may regain algae in future grow very slowly, are less able to recover from damage
Selected habitats 3: Tropical coral reefs- threats; how are introduced species a threat to tropical coral reefs? + example
Non-indigenous species have been introduced in several ways;
-From ballast water discharged from ships,
-Escaped fish & crustaceans from fish farms,
-Accidental & intentional releases from aquaria.
-The Red Lionfish was accidentally introduced to the Caribbean in the 1990s. They are indigenous to the Indian + Pacific Oceans but have few predators in the Caribbean Sea so they have spread rapidly. They are general predators, have reduced populations of many indigenous fish species
Selected habitats 3: Tropical coral reefs- threats; how is fishing a threat to tropical coral reefs?
-Isn’t always damaging but if the catch rate is excessive then over-fishing can reduce fish populations &affect other inter-dependent species
-The Crown of Thorns Starfish is a predator of coral polyps in the Indian & Pacific oceans. They’re eaten by Giant Triton molluscs. Overfishing of Giant Triton on Australian coral reefs allowed Crown of Thorns Starfish pop. to rise, leading to destruction of large areas of coral reef by starfish
Selected habitats 3: Tropical coral reefs- threats; how are coastal developments a threat to tropical coral reefs?
Expansion of coastal towns, construction of tourist resorts, ports & marinas can destroy coral reefs directly + increase turbidity causing damage to reefs near developments
Selected habitats 3: Tropical coral reefs- threats; how is the loss of associated habitats a threat to tropical coral reefs?
-Mangroves & seagrass beds help to trap suspended sediments + reduce water turbidity
-They also provide nursery grounds for many of the fish species that live as adults on coral reefs
-If mangroves & seagrass beds are damaged, then coral reefs nearby become damaged too
Selected habitats 3: Tropical coral reefs- conservation efforts; how can marine protected areas protect tropical coral reefs and what are examples of this?
-Many countries are trying to protect their coral reefs by designating Marine Protected Areas/National Parks eg Great Barrier Reef National Park in Australia, Barrier Reef Marine Protected Area in Belize & the Chagos Archipelago
A range of management practices can be used to protect the reefs;
-Fixed mooring buoys can be installed so boats don’t need to use their anchors
-Divers, snorkelers & swimmers can be taught not to touch coral/kick up sediments onto coral
-Fishing may be controlled/banned w/ the establishment of No Take Zones;
may actually increase long-term catches as protected breeding populations may produce more offspring that can move out & colonise other areas
-Sustainable development of ecotourism + fishing can ensure local economy is protected
-Environmental protection in other areas can benefit coral reefs eg protecting mangroves & seagrass beds, controlling soil erosion, controlling pollution + controlling developments like ports & tourist resorts
Selected habitats 3: Tropical coral reefs- conservation efforts; how can control of fishing protect tropical coral reefs and what are examples of this?
Fishing for some species that have been over-exploited may be banned so their populations can recover. Control methods include;
-Length of fishing seasons being restricted
-Placing a minimum catchable size to prevent capture of small fish, so they have a chance to grow larger & breed
-Imposing maximum catchable size to protect large individuals likely to produce many young
-Restrictions placed on damaging fishing methods eg dynamite fishing, trawling, fishing w/ small mesh nets
-No Take Zones (NTZ) may be established where fishing is banned; allows larger population of breeding adults to develop. Surplus young produced will spread out & colonise areas where fishing is permitted, increasing overall catches. Large NTZs, Chagos Archipelago, Indian Ocean; Great Barrier Reef, Australia. Small NTZs, Lundy Island, UK; Lamlash Bay, Isle of Arran, UK
Selected habitats 3: Tropical coral reefs- conservation efforts; how can control of tourism protect tropical coral reefs and what are examples of this?
Recreational activities may be restricted to minimise damage that may be caused. For example;
-Turtle nesting beaches may be protected to reduce disturbance
-Spear fishing may be banned
-Permanent mooring buoys may be installed so visiting boats don’t need to use anchors
-Collection of souvenirs may be banned, eg corals, mollusc shells
Selected habitats 3: Tropical coral reefs- conservation efforts; how can sustainable exploitation protect tropical coral reefs and what are examples of this?
Exploitation may be permitted but may be restricted to ensure it’s sustainable, eg in Belize the removal of soft coral sea fans is regulated by CITES Appendix II
Selected habitats 3: Tropical coral reefs- conservation efforts; how can reef creation protect tropical coral reefs and what are examples of this?
-Artificial reefs have been created from concrete structures eg ‘reef balls’ or by sinking structures that were made for other purposes like old ships & oil rigs
-In the Gulf of Mexico, several old warships & 400+ old oil rigs have been used to create artificial reefs
Selected habitats 4: Deep water coral reefs; what are the general features of deep water coral reefs?
-Found in water where sunlight doesn’t reach them
-Are also called cold water coral reefs
-Neither name is perfect as some are found in shallow water while others are found where water is relatively warm
-Common feature is the lack of sunlight to support photosynthetic algae within coral polyps
Selected habitats 4: Deep water coral reefs; what are the ecological features of deep water coral reefs?
Coral polyps that form deep water coral reefs don’t have the symbiotic photosynthetic algae found in tropical coral reefs so have much less food energy available & grow much more slowly than shallow-water tropical coral reefs; means that reefs recover much more slowly from damage than tropical coral reefs in shallow water
Selected habitats 4: Deep water coral reefs; what is the importance of deep water coral reefs?
-Have only been discovered since the 1970s w/ many being found since 2010, so there’s been little time for research into their importance, their ecological roles, or resources they may contain
-Often support a large biomass of fish but these are often slow-growing species w/ low reproductive rate so it’s easy to over exploit the populations
-The Roundnose Grenadier, Blue Whiting & Orange Roughy are deep water species that have been commercially fished. The Orange Roughy wasn’t exploited on a large commercial scale until 1980 but by 1990 the global catch was declining as the population had been over-exploited. Fishing of some populations has been banned in an attempt to let them recover
Selected habitats 4: Deep water coral reefs; what are the threats to deep water coral reefs?
-Deep water trawling has over-exploited fish populations, killed a lot of by-catch species & damaged the deep water reefs that support the fish
-The slow rate of coral reef growth means it will take many hundreds of years for damage to be repaired
-Expansion of oil & gas exploration in deep water is a future threat, as more
accessible supplies of oil + gas on land & in shallower water are depleted
-Increased releases of CO² are gradually causing the acidification of oceans. This may eventually threaten the survival of deep water corals
Selected habitats 4: Deep water coral reefs; what are the conservation efforts for deep water coral reefs?
Protected areas have been established to stop damaging activities like trawling eg Darwin Mounds SAC off NW coast of Scotland + Oculina Bank off the coast of Florida
Selected habitats 5: Oceanic Islands; what are the general features of oceanic islands?
-Islands that are sufficiently isolated from major land masses so it’s difficult for species to colonise
-Often produces unusual communities of species
Selected habitats 5: Oceanic Islands- ecological features; why are oceanic islands isolated and how does this affect them and their biodiversity?
-Most formed by volcanic eruptions/build-up of sand from nearby coral reefs
-Isolated positions make it difficult for most continental species to colonise
-Marine species & seabirds can colonise relatively easily as can plants w/ floating seeds
-Some species may have colonised by chance eg tortoises carried on drifting logs/terrestrial birds carried by strong winds
-Species that succeed in colonising will gradually evolve to occupy available ecological niches
-Evolution has produced unique species on different islands as conditions that affected selection pressure & characteristics that provide survival advantage, are different on different islands
-Biodiversity of isolated islands may be low as are difficult to colonise, so some taxa may be absent/have few original colonists, eg mammals, land birds, reptiles, amphibia & land plants
-Local evolutionary processes may produce many endemic species w/ small ranges & small populations that make them vulnerable to extinction
Selected habitats 5: Oceanic Islands- ecological features; why do oceanic islands have a lack of mammal predators and when are there exceptions?
-It’s difficult for mammals to colonise isolated islands
-Seals & bats may do so but not terrestrial mammals
-Some larger islands still have mammal species from when they were attached to larger continents but have evolved into unique species eg marsupials of Australia/lemurs of Madagascar
Selected habitats 5: Oceanic Islands; what is the importance of oceanic islands?
High proportion of endemic species increases possibility of the discovery of unique medicines/features that could be used in biomimetics
Selected habitats 5: Oceanic Islands- threats; how is the exploitation of species a threat to oceanic islands?
Some island species were heavily exploited in the past, usually for food eg the Dodo, giant tortoises, and marine turtles
Selected habitats 5: Oceanic Islands- threats; how are introduced species a threat to oceanic islands?
-Lack of mammal predators meant that indigenous species weren’t adapted to survive the arrival of predatory species eg rats from shipwrecks/cats introduced as pets
-Introduced herbivores eg goats & rabbits often destroy the indigenous plant communities. Lack of predators allowed herbivore populations to become very large
-Introduced plants may have colonised & out-competed indigenous vegetation
-Pathogens may have been introduced that affect indigenous species. Avian malaria was introduced to Hawaii which has killed off many bird species. Above 1500m malaria rarely occurs because it’s too cold, but as global warming cause temps to rise, avian malaria spreads to higher altitudes & range of indigenous bird species is reducing
Selected habitats 5: Oceanic Islands- threats; how is habitat destruction/change a threat to oceanic islands?
-Urban, agricultural & tourist developments have caused habitat destruction
-Sea level rise is also a threat
Selected habitats 5: Oceanic Islands; what have the conservation efforts for oceanic islands involved?
-Usually involve attempts to stop/reverse damaging effects of human actions
-Biggest single action that has conserved endemic species has been eradication of introduced species eg rats, goats, cats & rabbits
-Introduced species have been successfully eradicated from nearly 1000 islands, eg rats in Ramsay Islands in Wales, Flatey in Iceland & several islands in Hawaii
Selected habitats 6: Mangroves; what are the general features of Mangroves?
-Coastal forests that grow in saline, oxygen-deficient soils, usually in tropical areas
-Provide range of important resources & ecological services
Selected habitats 6: Mangroves; what are the ecological features of Mangroves?
-Tropical forests dominated by halophytic trees that live in inter-tidal areas w/ saline water
-Are adapted to survive conditions that are saline, anaerobic & stormy
-Inter-tidal habitats also have extremes in conditions eg temps & availability of water
Selected habitats 6: Mangroves- importance; why is the biodiversity of mangroves important?
Provide a habitat for a wide variety of species, including crabs, lobsters, shrimps, sponges, fish, molluscs, reptiles, & birds
Selected habitats 6: Mangroves- importance; why are mangroves important for coastal erosion protection?
-Vegetation & prop roots of mangroves absorb energy of waves, reducing impact of storms + hurricanes on more vulnerable coastal areas behind mangroves
-2004 tsunami that caused devastation in SE Asia did least damage where communities still had intact mangroves
Selected habitats 6: Mangroves- importance; why are mangroves important for fisheries?
-Provide important nursery grounds for fish that spend their adult lives in the open sea/on coral reefs
-Dense roots protect young fish from larger predators
Selected habitats 6: Mangroves- importance; why are mangroves important for the protection of coral reefs?
-Reefs are damaged by suspended solids carried by rivers that then sink onto coral polyps & kill them
-River water that flows through mangroves slows down & suspended solids are deposited before they reach reefs
-Mangroves also absorb nutrients from farmland which then can’t cause growth of algae on coral reef which would threaten survival of coral polyps
Selected habitats 6: Mangroves- importance; why are mangroves important for resources?
Provide timber for construction & fuel
Selected habitats 6: Mangroves- importance; why are mangroves important for medicinal resources?
-Many mangrove plants have been used in traditional herbal medicines -Extracts of the leaves of some mangrove trees are being researched as antimicrobial medicines to treat antibiotic resistant bacteria eg MRSA
-A cyanobacterium from Caribbean mangroves is used to treat small-cell lung cancer
Selected habitats 6: Mangroves; what are the threats to mangroves?
Growth of human populations & expansion of econ developments eg aquaculture, urban developments & ports cause large-scale mangrove destruction
Selected habitats 6: Mangroves; what are the conservation efforts used for mangroves + example?
-In regions where protection of mangroves is seen as important surviving mangroves may be designated as protected areas
-75% of mangroves of Sri Lanka have been lost but remaining areas were legally protected in 2015
-In areas where mangroves have been lost, natural recolonisation/replanting by people may take place
-Natural regeneration can be very quick as mangrove trees produce seeds that germinate before they fall off parent tree, into the sea where they’re carried by water currents. If the sprouted shoot touches sand, then roots are produced which anchor the young plant to the seabed
Selected habitats 7: Antarctica; what are the general features of Antarctica?
-Is an unusual area w/ extreme & fluctuating abiotic conditions; have produced a unique community of species
-The only polar land mass & is the last pristine continent
-Has unique features & is vital in maintaining conditions across the Earth. These factors have driven the campaign to preserve it
-It’s a large continent surrounded by ocean, while the Arctic is an ocean surrounded by land
Selected habitats 7: Antarctica- ecological features; what are the unique features of Antarctica?
-Large landmass; almost x60 size of the UK
-Ice & snow, up to 4.8km deep, cover 98% of its surface
-Average temp of -49C; coldest continent on Earth
-Low precipitation w/ snow falling mainly near coast & has Earth’s largest desert
-High average altitude
-Little terrestrial life including no permanent human inhabitants
-Abundant marine life in surrounding sea
-High levels of marine nutrients in surface water are brought up from seabed by upwelling currents. These nutrients support a rich food web
-Large seasonal variations in ice cover as seasonal changes in temp cause sea ice to freeze/melt
-Extreme seasonal changes, esp light levels w/ 24hr daylight in summer & 24hr darkness in winter. The summer sunlight & high nutrient levels produce a rich phytoplankton bloom that supports the rest of the foodweb
Selected habitats 7: Antarctica- ecological features; how are species impacted by the climate of Antarctica?
-Few terrestrial plants/animals can survive its harsh climate w/ its low air temps & long Antarctic winter
-Sea is warmer than land, w/ temperatures ranging from -1.8°C to +3.5°C. Most of the animals found in Antarctica get their food from the sea, eg penguins, seals, & albatrosses
-A lot of the krill rely on the sea ice as they shelter from predators in cracks under ice where they feed on algae
Selected habitats 7: Antarctica- importance; why is Antarctica important for the control of natural cycles?
-Ice on land is a huge store of water w/ 70% of Earth’s fresh water present as ice on Antarctica. This long-term storage of water has kept global sea levels relatively low
-Ice has a high albedo so most sunlight is reflected away, reducing its warming effect. If the area of ice was reduced, then temps would rise
-Much of carbon present in algae eaten by krill sinks to the seabed in krill faeces. This carbon sequestration helps to reduce CO² concentrations in the atmosphere
Selected habitats 7: Antarctica- importance; why is Antarctica important for resources?
-Harvested biological resources include krill & 3 fish species
-Exploitation of the mineral resources of Antarctica is currently illegal but it’s known that there are reserves of gold, silver, nickel, titanium, uranium, coal, oil & other potentially exploitable resources
Selected habitats 7: Antarctica- importance; why is Antarctica important for research?
-Is a unique location for scientific research
-It’s the most isolated place on Earth so human influences are small
-It’s a good place for astronomical research as there’s little pollution interference from light, infra-red, radio waves. There is also little cloud cover to block observations.
-Climate is relatively stable & predictable so it’s a good place for climate research
-Unique wildlife makes it an important place for ecological research
Selected habitats 7: Antarctica- threats; how does global climate change threaten Antarctica?
-Rises in temp & sea level caused by global climate change are having significant impacts, esp around coast & on Antarctic peninsula which extends further north than rest of Antarctic land mass
-Although rise in global temps due to climate change is unlikely to melt much of the ice in Antarctica as it’s so cold, if any ice did melt it’s likely it would affect remaining ice significantly. Glaciers could move more rapidly towards ocean caused by lubrication from released meltwater. At the same time, ice shelves in coastal water which block seaward movement of glaciers could break up as seas heat up, enabling glaciers to move towards sea more easily
-Sea level rise may also cause ice shelves to lift off seabed on which they were grounded; may then break up into icebergs & float away, removing barrier to land ice behind which could then flow towards sea
Selected habitats 7: Antarctica- threats; why does the area of sea ice forming each winter in Antarctica show an upwards trend despite climate change?
-Stronger winds may be spreading the ice further
-Warmer air can hold more water vapour which may cause more snow to fall. This increased snow & slush ice on which it falls may freeze together to form ice
-Ice on land that melts & flows into sea may produce layer of floating fresh
water which freezes more easily than sea water
Selected habitats 7: Antarctica- threats; what is the long-term trend occurring in Antarctica due to global climate change and why is this impactful?
-Reduction in extent of sea ice; would affect marine food web as decline in populations of algae & krill that live under sea ice would affect species that rely on them for food
-Ice on land in Antarctica has a mean thickness of 1,800m, so there’ll be no significant reduction in area of land ice for very long time even if melting increases
-However, sea ice is only 1-2m thick, so warming could cause reduction in sea ice area; would reduce albedo of ocean & allow further warming as more sunlight is absorbed
Selected habitats 7: Antarctica- threats; how is ozone depletion a threat to Antarctica?
-Raised UV levels caused by ozone depletion has had little impact on organisms that live on land as there are few of them & animals that are present often have thick feathers/fur
-Planktonic organisms in surface waters are more vulnerable to raised levels of UV, eg algae, krill & larvae of fish + sea urchins
Selected habitats 7: Antarctica- threats; how is tourism a threat to Antarctica?
-Unregulated tourism could threaten Antarctic wildlife via disturbance & introduction of non-indigenous species + pathogens from humans
-Pollution caused by fuel, sewage & wastes could also increase
-Number of tourists visiting Antarctica is increasing rapidly although there have been proposals for a cap on numbers
-Most people visit by ship as there’s no tourist accommodation on Antarctica
-Most tourists visit small number of landing sites which reduces wider impact but increases dangers for these sites
-Disposal of wastes, oil spills & disturbance of wildlife are all potential issues
-There’s also concerns that pathogens may spread from humans to wildlife
Selected habitats 7: Antarctica- threats; how is scientific research a threat to Antarctica and how is this reduced?
-Research in itself isn’t a threat to Antarctica but carrying it out increases risk of impacts like pollution events & wildlife disturbance
-Strict regulations are in place to minimize the impacts
Selected habitats 7: Antarctica- threats; how is overfishing a threat to Antarctica?
-Sea around Antarctica has many species that have been over-exploited in the past, leading to dramatically reduced populations, eg some whale species & fur seals
-Current fishing for krill threatens species that feed on it incl whales, albatrosses & penguins
-Overfishing of Patagonian Toothfish threatens food supply of Sperm Whales + Elephant Seals
-Longlining for toothfish also threaten albatrosses as they can be caught on the hooks & drown
Selected habitats 7: Antarctica- threats; how is future mineral exploitation a threat to Antarctica and why is this undermined?
-Has deposits of minerals eg coal, oil, iron, copper, chromium & platinum
-Pressure to exploit these will increase as reserves elsewhere are depleted
-Although mineral exploitation is currently banned, Antarctica has deposits of many minerals that are becoming scarce elsewhere in the world
-Legal protection & difficulties of operating in such an extreme environment mean that mining is unlikely in the foreseeable future
Selected habitats 7: Antarctica- conservation efforts; what is the 1959 Antarctic Treaty?
Was set up to protect Antarctica & has been signed by 52 countries, including all the countries active in the area
Selected habitats 7: Antarctica- conservation efforts; how does the conservation of living organisms help protect Antarctica?
-Fishing is regulated by the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLS)
-Krill & some fish species are exploited but fisheries are closed if populations become over-exploited
-No mammal species can be exploited commercially
Selected habitats 7: Antarctica- conservation efforts; how does the control of tourism help protect Antarctica?
Impact is reduced by;
-Having no holiday accommodation on land so wastes are kept on tourist cruise ships
-Allowing only 1 cruise ship at any site at one time, w/ maximum of 100 visitors ashore
-Tourists having to be accompanied by trained guides
-Requiring tourists to stay at least 5m from wildlife & leave no litter
-Wearing protective clothing to prevent introduction of pathogens & non-indigenous species. Protective clothing is cleaned before another site is visited
Selected habitats 7: Antarctica- conservation efforts; how does waste management help protect Antarctica?
Done by;
-Controlling & removing wastes
-Ensuring that only long-term residents on Antarctica are research scientists & support staff
-Any waste materials produced being removed, eg fuel containers, batteries, toxic wastes, plastics, used lubricating oil
-Ensuring sewage is only discharged into sea where currents will disperse & dilute it so that microbes in sea can break it down
-Removal of wastes produced before introduction of these regulations, unless it’d cause more environmental damage to do so
Selected habitats 7: Antarctica- conservation efforts; how does the restriction of military activities help protect Antarctica?
None are allowed (except when supporting scientific research) & nuclear explosions are permitted nor dumping of radioactive waste
Selected habitats 7: Antarctica- conservation efforts; how does the restriction of resource exploitation help protect Antarctica?
No commercial mineral exploitation is allowed
