Conservation Of Biodiversity Flashcards
1
Q
Why is important to conserve biodiversity for resources?
A
- Wood: buildings, tools, furniture
- Fibres: cotton, wool, silk, rayon
- Oils: vegetable and animal oils are used in foods, lubricants, soaps
- Fuels: wood, charcoal, alcohol, vegetable oils
- Food: plants, animals, algae, fungi
2
Q
Why is important to conserve biodiversity for new food species?
A
- Very few species of plant or animal are used for human food, and are often kept in areas they are not evolved to live in
- Indigenous species are usually better adapted to local conditions, so may have higher survival rates
- lots of plants have potential including: Potato Bean of North America, Yeheb tree has edible nuts, Kernza - a perennial cereal
- Lots of animals too: American Bison, Common Eland, Common Ostrich
3
Q
Why is important to conserve biodiversity for biomimetics- vehicle design?
A
- Splayed wingtip feathers of soaring birds rescue wind turbulence and drag, helping to improve aircraft desgin and increase fuel efficiency.
- Humpback whale tubercles on their flippers, channel water flow allowing them to turn in tigh circles, this ha been applied to ship designs for rudders
4
Q
Why is important to conserve biodiversity for biomimetics-infection control?
A
Bacteria doesn’t easily stick to shark skin, this is because they have a special coating, which has now been imitated in operating theatres to control bacterial infections.
5
Q
Why is important to conserve biodiversity for biomimetics-Architecture?
A
The mounds termites construct above the ground to absorb sunlight and become hot. Using convection currents, this system has been copied in shopping complexes and office blocks to create natural ventilation and cooling without the need for air conditioning.
6
Q
Why is important to conserve biodiversity for biomimetics-Adhesion?
A
- Toes of gecko lizards have pads that provide strong adhesion = used to provide adhesion without glue
- Seeds of some plants have burrs with hooks that stick to animals for seed dispersal = Velcro
- Lotus flowers water-repelling properties = self-cleaning glass
7
Q
Why is important to conserve biodiversity for biomimetics-materials?
A
Lightweight, flexible, strong silk produced by spiders being copied to produce better car airbags and body armour
8
Q
Why is important to conserve biodiversity for medicine?
A
Many plants produce chemical toxins for self defence:
- Poppies = painkillers e.g. morphine and codeine
- Willow tree bark = Aspirin
- Tropical marine sponge = AZT to treat HIV/AIDs
9
Q
Why is important to conserve biodiversity for physiological research?
A
Studying species adaptations to environmental conditions in the interest of understanding human health greater:
- Marsupials pouches, studying kangaroo development = better understanding of a baby inside the womb still.
- Hippopotamus skin secretes and acid which is a natural sunscreen = treatment of burn victims
- Bat and Dolphin echolocation = ultrasound scanners, 3-D images for medical diagnosis
10
Q
Why is important to conserve biodiversity for pest control species?
A
- Parasitic wasp (Encarsia Formosa) released in greenhouses or control whitefly pests
- Cactoblastis moth to kill of prickly pear cacti in South America
11
Q
Why is important to conserve biodiversity for genetic resources?
A
Domesticated crops often lack genetic diversity, Crop Wild Relatives have been introduced to be bred with the domesticated crops as they often hold desirable characteristics:
- Disease resistance
- Salt-tolerance
- Resistance to drought
- High yields
- Improved taste or appearance
- Nutrient uptake
12
Q
Why is important to conserve biodiversity for centres of diversity?
A
Some areas of the world have high concentrations of the close relatives of the crop species, these were named Centres of diversity or Vavilov centres.
E.g. Chinese centre = millet, soya, onion, cucumber, pear, peach, apricots, sugarcane and opium poppy
13
Q
Why is important to conserve biodiversity for ecosystem services-atmospheric composition?
A
Abiotic and biotic processes that cancel each other out to create dynamic equilibrium
E.g. Concentrations of carbon dioxide and oxygen are largely regulated;acted by photosynthesis and aerobic respiration
14
Q
Why is important to conserve biodiversity for ecosystem services-hydrological cycle?
A
Evapotranspiration from vegetation produces a large amount of the water vapour that forms clouds, controls surface temperatures and increases precipitation.
15
Q
Why is important to conserve biodiversity for ecosystem services-biogeochemical cycles?
A
Cycles such as the nitrogen, carbon and phosphorus, all rely on microbes such as bacteria and fungi. Without these processes, waste products would build up and nutrient resources would become depleted.
16
Q
Why is important to conserve biodiversity for ecosystem services-soil maintenance?
A
Soil is vital for growth, regulating water cycles, reducing flooding.
The formation process involves break down and decomposition which involves animals, fungi and bacteria.
17
Q
Why is important to conserve biodiversity for ecosystem services-interspecies relations?
A
- All species rely on other species for a range of resources such as food, shelter, protection etc.. and ecological services.
18
Q
Why is important to conserve biodiversity for ecosystem services-food?
A
All heterotrophs rely on other organisms as a source of energy and nutrients
19
Q
Why is important to conserve biodiversity for ecosystem services-pollination?
A
- Pollination by insects = plants have dispersed populations as insects search over large distances, the plants also save energy as they do not need to produce as much pollen
- Pollination by animals = important in forests as trees slow wind velocity
- Many plants have evolved for specific pollinators and pollinators have evolved from specific plants
E.g. Darwins Orchid = Sphinx Moth as they have a long enough tongue
20
Q
Why is important to conserve biodiversity for ecosystem services-seed dispersal?
A
- Seed dispersal by animals = not haphazard, seeds can travel longer distances, increases survival of the seeds as they have more nutrients
- Plants often attract animals with bright fruits or flowers
- Faecal matter can act as a fertiliser
21
Q
Why is important to conserve biodiversity for ecosystem services-habitat provision?
A
One species may provide habitats for other species:
- Trees = nests for birds
- Hermit crabs = shells of dead molluscs
- Trees = microclimates beneath the canopy
22
Q
Why is important to conserve biodiversity for gene-pool problems?
A
Gene pool = total number of different genes present in all individuals in a population of a particular species
- Domesticated species often lack genetic diversity and so are often all susceptible to the same environmental changes
- Large gene pool = larger range of tolerance = better at adapting to change
-
23
Q
How is direct exploitation of food a threat to biodiversity?
A
Many species are overexploited to provide food for humans e.g. turtles, cod swordfish, tuna, sharks and many herbivores, some have been hunted to extinction e.g. dodo birds
24
Q
How is direct exploitation of fashion a threat to biodiversity?
A
Animal skins for clothing, certain animals particularly are affected:
- Fur coats and accessories = leopard, snow leopard, ocelot, tiger, fur seals
- Leather bags and shoes = crocodiles and alligators
- Feathers from kingfishers, parrots and ostriches
25
How is direct exploitation of pets and entertainment a threat to biodiversity?
Pets: parrots, lizards, snakes, tortoises, tropical fish
House plants: tropical exotics, fly traps
Zoos: used to be wild animal collections, nowadays they are for conservation reasons
Aquaria: most marine fish do not breed well in captivity
Marine life centres: whales and sharks and dolphins that have been caught from the wild
26
How is direct exploitation of furniture and ornaments a threat to biodiversity?
Furniture = timber from tropical rainforest species like mahogany, teak and ramin
Black piano keys = tropical ebony wood, white piano keys = elephant ivory
Jewellery = shark teeth, turtle shells and mollusc shells
Coral and sea shells collected by tourists, sold as souvenirs
27
How is direct exploitation of traditional medicines a threat to biodiversity?
Little evidence that they are as effective as medicines, many species were used:
- Tigers = claws as a sedative, tail for skin disease, dung for alcoholism, brain for laziness, whiskers for toothache
- Rhinoceroses = horn cure for many problems from nosebleeds to smallpox
- Sea horses = treat infertility, baldness, asthma and arthritis
28
How is direct exploitation of other products a threat to biodiversity?
- Fine oils from whale blubber
- Spermaceti from sperm whales
= used to make candles, lamp oil, soap, lubricating oil, cosmetics and perfume
29
How does eradication of predators and competitors threaten biodiversity?
Many species killed if they threaten human life or activities:
- Sharks, snakes, crocodiles = threat to humans
- Malaria mosquitoes = pathogen vectors
- Wolves, lions, puma, birds, seals = predators of livestock
- Insects, fungi, birds molluscs = agricultural pests
- Rabbits and deer = competitors of agricultural species
- Beetles, deer, squirrels, beavers = forestry pests
30
How can changes in the abiotic factor, water availability threaten biodiversity?
Land drainage for farmland means large areas of wetland no longer exist = wetland species no longer survive
Hydroelectric power schemes cause flooding and flood nests killing eggs
31
How can changes in the abiotic factor, dissolved oxygen threaten biodiversity?
Dissolved oxygen can be reduced by hot water discharges which deoxygenates the water
= Reduced survival rate of aerobic organisms
32
How can changes in the abiotic factor, temperature threaten biodiversity?
Global climate change = temperature changes will cause changes in the distribution of species, or they will die out where they are as the conditions are no longer suitable
Hot effluent water = increase growth rates of aquatic vegetation = deoxygenation
33
How can changes in the abiotic factor, pH threaten biodiversity?
Mine drainage water and pollutant gases from burning fossil fuels can produce acidic conditions, which can denature the enzymes of exposed tissues.
Particularly vulnerable = fish eggs, gills, calcium based exoskeletons
34
How can changes in the abiotic factor, water turbidity threaten biodiversity?
Ploughing, mining and dredging can increase water turbidity
- Reducing light penetration and preventing submerged aquatic pants from photosynthesising
- Can kill-filter feeders as their gills become blocked
35
How can changes in the abiotic factor, physical damage threaten biodiversity?
Discarding litter or old fishing gear = can be swallowed by or trap an animal
36
How can changes in the biotic factor, pollinators threaten biodiversity?
Many plants rely on pollen being transported between flowers
- If insects die out, plants wont be able to reproduce
- Use of pesticides and loss of flowering plants has reduced populations of insect species
37
How can changes in the biotic factor, seed dispersal species threaten biodiversity?
Animals that eat seeds and fruit can be vital in the successful spiral of seeds.
- Elephants disperse most of the seed for tree species where elephants are found
38
How can changes in the biotic factor, food chain impacts threaten biodiversity?
Decline in populations of some species may be caused by the over-exploitation of their food e.g. puffins reduced as sand eels over exploited
Increase in populations of the prey of over-exploited predator species such as increase in jellyfish due to decrease in sea turtles
39
How do introduced competitors threaten biodiversity?
- Grey squirrels were introduced to UK from North America, where in many areas it has outcompeted the red squirrel as it is better adapted to exploit available food, can compete for better nest sites.
- Rhododendrons were introduced to the UK from Asia, but are invasive, and are evergreen so prevent growths of native vegetation, and release toxins that inhibit growth of other plants
40
How do introduced predators threaten biodiversity?
- The range of the European Water Vole in Uk rivers has been reduced by the American Mink that escaped from fur farms
- Ground nesting birds on many oceanic islands such as New Zealand, Australia and Hawaii are threatened by cats, rats, pigs and dogs
- Nile Perch was introduced into lake Victoria to improve food supplies but it ate the indigenous fish such as cichlids
41
How do introduced pathogens threaten biodiversity?
- Grey squirrel brought squirrel pox virus which doesn’t effect them but is deadly to the red squirrels
- White-clawed Crayfish is indigenous to the UK but has declined due to introduction of non indigenous species which carry a fungal pathogen killing the White-clawed Crayfish
- Dutch Elm Disease, Ash Dieback and Sudden Oak Death
42
How does introducing species that hybridise threaten biodiversity?
If a species very closely related to an indigenous species is introduced the cross-breeding may produce fertile hybrids.
E.g. Wildcats in Scotland bred with domestic cats
43
How does introducing loss of species that control abiotic factors threaten biodiversity?
Some species change habitats and produce abiotic factors that other species need for survival
E.g. African Forest Elephants create forest clearings and water holes that other species may rely on.
If these species are lost then other species may decline.
44
How does habitat destruction threaten biodiversity?
Human activities cause habitat destruction such as deforestation, ploughing of grassland, reservoir creation, mineral extraction, urban expansion.
45
What does wildlife conservation involve?
Interfering with habitats or wild populations in ways that are intended to be beneficial for conservation
46
What does IUCN stand for?
The International Union for Conservation of Nature
47
What are the roles of the 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
48
What are the IUCN red list categories? (In order)
Extinct = no known individuals remain
Extinct in the wild = only remain in captivity
Critically endangered = extremely high risk of extinction in the wild
Endangered = high risk of becoming endangered
Vulnerable = high risk of becoming endangered
Near threatened = likely to become endangered
Least concern = lowest risk of becoming endangered
Data-deficient = insufficient information for the species
49
What’s an example of a species recategorised in 2016 on the IUCN?
Plains Zebras has been recategorised from Least Concern to Near threatened because of declining population mainly caused by habitat loss.
50
What are examples of species recategorised in 2015 on the IUCN?
- Successful conversation of the Iberian Lynx has resulted in re-categorisation from Critically Endangered to Endangered. Due to a captive breeding programme
- White-headed vulture has been re-categorised to Critically Endangered as the population has continued to decline dues to poisoning and persecution
51
What are some species assessed in 2014 on the IUCN?
- 100 species of Lemur all endemic to the island of Madagascar, 22 are critically endangered, 48 are endangered due to habitat loss and bushmeat.
- Fregate island Beetle of Fregate island in the Indian Ocean was categorised as threatened, but a programme to remove rats resulted in a recategorise to Vulnerable
52
What are some species assessed in 2013 on the IUCN?
- Okapi is indigenous to forests in the Democratic Republic of Congo, its population declined dues to hunting, habitat loss, and the difficulties in conservation programmes as early as military conflict has caused it to be recategorised from Near Threatened to Endangered Species
53
Why is species, in habitats under a particular threat, a reason for categorising them?
Their status may indicate the status of the rest of the community of species, such as the decline of lemurs in Madagascar is used to predict the decline of other species.
54
Why are Evolutionarily Unique species (EDGE) a reason for categorising them?
Species that have a high degree of evolutionary uniqueness may be categorise, e.g. if there are only few closely related species.
E.g. Bacteria Camel, Pygmy Hippo
55
What does EDGE stand for?
Evolutionarily Distinct and Globally Endangered
56
Why are endemic species a reason for categorising them?
Means not in any other area, so if there is a change in the threats to its survival and it dies out locally, there will be no surviving population elsewhere. E.g. Galapagos, Seychelles, Hawaii, Madagascar = Gozo Wall Lizard, Red ruffed Lemur, Aldabra Giant Tortoise.
57
Why are keystone species a reason for categorising them?
A key stone species has an important role on maintaining the ecological structure of a community. Its importance is usually great compared to their low abundance or population biomass. Roles include provision of food, seed dispersal, creation of structural features
E.g. African Forest Elephants
58
Why are flagship species a reason to categorise them?
Flagship species are species with a high public profile that often raise support to protects other species.
E.g. Tigers, elephants, lions, etc to raise support for spiders, bats, moths, etc which are just as important
59
Why is degree of population dispersal a reason to categorises them?
When the global population of a species is fragmented into a number of isolated population it is important to ensure that viable local populations are maintained.
Habitat fragmentation can cause small gene pools = interbreeding, or lack of sufficient resources.
60
What is the Wildlife and Countryside Act (1981) and what does it cover?
It is a Uk law which includes much of legislation that protects UK wildlife:
- Designated protected areas
- Protection of wild birds and their nests
- Protection of mammals
- Stopping the uprooting of wild plants
- Protection of bats so they are not disturbed
61
What ways does designation of a protected area protect habitats and species?
- Protection of species and habitats
- restrictions on activities outside and inside the protected areas
- Management agreements between the landowner and designating organisation
- Access restrictions
- International cooperation
62
What does SSSI stand for?
Site of Special Scientific Interest
63
What does NNR stand for?
National Nature Reserve
64
What does SAC stand for?
Special Area of Conservation
65
What does SPA stand for?
Special Protection Area
66
What are Natura 2000 sites?
These are SACs and SPAs
67
What are Ramsar sites?
Wetland of international significance in terms of ecology, botany, zoology, limnology or hydrology.
68
What does MNR stand for?
Marine Nature Reserve
69
What does LNR stand for?
Local Nature Reserve
70
What does MPA stand for?
Marine Protected Area
71
What does MCZ stand for?
Marine Conservation Zone
72
What does CITES stand for?
Convention on International Trade in Endangered Species
73
How are CITES selected species categorised?
Appendix 1: species threatened with extinction, all international trade is banned except movement for conservation breeding programmes e.g. all great apes, all big cats, al rhinos etc
Appendix 2: species that may be threatened with extinction if trade is not closely controlled. Trade is permitted from countries where the species is well protected so limited exploitation does not threaten their survival e.g. Honduras Mahogany and Common Hippopotamus
74
What does the IWC stand for and what are their aims?
International Whaling Commission.
- Banned whaling in 1986 as populations were so depleted
Aims:
- total protection for certain species
- designation of whale sanctuaries
- setting limits on numbers and sizes of whales that’s can be taken
- protection of suckling mothers and their calves
- carrying out research into whales that’s biology and activities that threaten whales such as ship strikes and entanglement in fishing nets
75
What are the three reasons Whaling can take place?
- Aboriginal subsistence = whaling is permitted for cultural groups that have traditionally hunted whales for food e.g. Inuit of Alaska have a catch quota of 55 Bowhead whales per year.
- Special Permit Whaling of Scientific Whaling = involves the killing if whales for scientific research
- Commercial Whaling = Iceland and Norway use an IWC regulation to set a quota of 800 Fin and Minke whales in 2014
76
What does EU CFP stand for and what are their aims?
Common Fisheries Policy of the European Union = a series of regulations that control fishing within the territorial waters of the European Union, to ensure fishing is environmentally, economically and socially sustainable, provide healthy food source.
Aims:
- catch quotas to limit the total mass that can be landed
- size limits, so fewer small fish are killed and have a chance to grow
- net mesh-size regulations that allow smaller fish to escape survive and have the chance to grow larger and breed
- limits on fishing effort, maximum size of boats, number of days of fishing limits
- a ban on the discarding of unwanted fish
77
What does ITTO stand for and what are their aims?
International Tropical Timber Organisation = aims to encourage sustainable management of tropical forests
- 1990
- agreed to strive for an international trade of tropical timber from sustainably managed forests by 2000, without unsustainable exploitation
- little evidence if success
78
What are the factors that influence decisions about captive breeding and release programs?
- 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?
79
What specific habitat requirements make is difficult to keep species in captivity?
- habitat size = some species require very large spaces e.g. whales
- food requirements = some species have very specific requirements that cannot easily be provided e.g. insectivorous bats
- species interrelationships = some species have complicated species interrelationships such as plants with symbiotic mycorrhizal root fungi relationships
- financial constraints = expensive
80
How does conditions for breeding inhibit breeding success?
- precise timing of breeding is vital, breeding is often triggered by a stimuli a such as day length, light levels, temperatures, amount of food
- if these conditions are not known then they will not breed
81
How does population interactions inhibit breeding success?
- in the wild, breeding pairs of birds may choose isolation, in captivity breeding and non-breeding are all kept together, which can cause conflict and reduce breeding success
82
How does breeding habitat inhibit breeding success?
- some species can only breed if they have suitable habitat such as one that includes suitable courtship display, area for hunting, social groping or nesting sites
E.g. flamingos only breed in large groups
83
How does gene pool size inhibit breeding success?
- small gene pool = increased risk of inbreeding
- stud book can be kept together see who is related to who
84
How does hybridisation inhibit breeding success?
85
How does cryopreservation increase breeding success?
- storage of eggs, semen and embryos
- can be transported long distances much more easily
- production off offspring without mating successfully
- can be stored for years
86
How does artificial insemination increase breeding success?
- collection of semen form a male and its insertion into a female to produced offspring
- can be stored for years
- animals don’t have to mate or live together
- animals don’t have to be transported
87
How does embryo transfer increase breeding success?
- some mammal CB populations have very few breeding females
- so closely related species can act as surrogate others
- female of endangered species is treated with hormones so she ovulates and releases a large number of eggs
- eggs are washed out and fertilised with sperm
- each embryo is implanted into a female of a more common species
- who give birth to the endangered species
88
How does micro-propagation of plants increase breeding success?
- tissue culture where many clusters of cells can be produced from a single plant or tissue sample
- each cell cluster can be cultivated
- many plants can be produced from a single parent plant
- they will all be genetically identical though
89
How does cloning increase breeding success?
- limited success in animal species
- cloning involves production of embryos by transferring the nucleus from a stem cell of the endangered species into an empty egg of a closely related species
- egg is implanted into a female
- cutting of mature plants can be cultivated to produced many genetically identical plants
E.g. northern white rhinos and Atlantic bald poplar
90
What are the key features of a successful releases program?
- large enough suitable habitat
- relatable food supplies
- low predation risk
- suitable breeding sites
- water
- support of the local human population
- official support e.g. legal protection of the habitat and species
91
What is a hard release?
- no post-release support
- usually for species where behaviour is controlled by instinct and do not need to learn survival skills
E.g. insects, fish, reptiles
92
What is a soft release?
- post-release support
- gradual release into the larger areas
- provision of food as they learn how to find it themselves
E.g. mammals and birds
93
What are problems faced by released individuals?
- finding and recognising food
- recognising poisonous foods
- developing hunting skills
- recognition and avoiding predators
- being accepted into the social groups of the wild populations
94
What are seed banks?
- set up to store the seeds of wild plants so that the species would not become globally extinct if they become extinct in the wild
- if a species becomes rare in the wild, the seeds stored in the seed bank should maintain the biodiversity of the species
Millennium Seed Bank at Wakehurst Place in Sussex holds over 10000 seeds of each species
- stored under ground in a vault
95
How does land ownership support habitat conservation?
Wildlife conservation organisations purchase areas to protect the species that already live there, or will do so once the conditions have been changed so they are suitable e.g. RSPB, National Trust, Woodland trust, and individual land owners
96
How do designated protected areas support habitat conservation?
Establishes the legal status for the protection of an area.
E.g. SSSIs, NNRs, SACS, SPAs, and Ramsar sites = wetland protection
97
How do voluntary agri-environmental schemes support habitat conservation?
- managing habitats for the benefit of wildlife can be expensive so landowners may join voluntary governmental schemes which provide financial support needed
- agri-schemes recognise that much of British landscape was produced by farming and can only be conserved by the continuance of appropriate farming practises
- they provide financial support to farmers to reward and encourage environmentally beneficial developments
98
What are some examples of agri-environmental schemes?
Environmentally Sensitive Areas (ESA)
Countryside Stewardship Scheme (CSS)
Environmental Stewardship Scheme (ESS)
Countryside Stewardship (CS)
99
What do most agri-environmental schemes aim to do?
- conserve wildlife
- maintain and enhance landscape quality and character
- protect the historic environment
- promote public access and understanding
- protect natural resources
100
What features of a farm will be rewarded points if they have them?
- beetle banks
- hedgerows
- buffer strips
- wild bird seeds
- low input grasslands
- protected archaeological sites
- management to reduce soil erosion
- protection of in-field trees
- restoration of habitats
- public access
101
What is unintentional habitat creation?
Human activities create new habitats which may be suitable for other species to live in
E.g. reservoirs, flooded sand and gravel pits, roadside verges, hedgerows and ornamental gardens
102
What is intentional habitat creation?
It takes a while for species to colonise an area until it is suitable, so habitats are made to be able to suit them after so they can colonise faster
E.g. wetlands, new woodlands, wildflower meadows and artificial coral reefs
E.g. Lakenheath and Wallasey island are both RSPB reserves and used to be arable farmland before habitat creation for wildlife began
103
How is habitat area decided when designing a new habitat?
Habitat must be large enough to support viable populations, especially for solitary animals which occupy a larger space individually so for a population of them they will need a very large space
Some species benefit from small habitats like frogs, toads and newts breed more successfully in ponds that are too small to support the predatory fish that would eat their eggs and tadpoles
104
How are biological corridors fit in when designing new habitats?
Linking isolated areas of the same habitat type allows the dispersal of young animals if there is a local breeding surplus and the mixing of different populations and gene pools which reduces the risk of inbreeding
- if a species dies out in one area, then re-colonisation from other areas is possible, they can also be used to allow animals to avoid hazards when moving between habitats
105
How is habitats shape decided when designing a new habitat?
The perimeter if a habitat will have a strip where the conditions are a combination of the two neighbouring habitats, some species benefit from these conditions e.g. higher light levels at the edge of the wood, but may not be suitable for species that require core habitat conditions
106
How is habitat diversity important when designing new habitats?
Natural habitats are really uniform and usually have local variations in conditions, producing a greater range of possible niches
This increases biodiversity as different species colonise the areas to which each is best adapted
107
How are light levels important when designing habitats?
The shading effect of dense tree cover inhibits the growth of plants of the woodland floor, this can be reduced by selectively felling individual trees to create suitable conditions for smaller plants that need more light
108
How is water depth important when designing new habitats?
May of the plants and animals that live in aquatic habitats will colonise areas with particular water depths, the dominant plants are those that absorb most sunlight often by being taller
As water depths increases the plant community changes as root anchorage and nutrient absorption from the sediments becomes more difficult, which explains the plant community changes that happen in a hydrosere during ecological succession as the water depth increases
109
How is vegetation age structure important when designing a new habitat?
A natural woodland will have an age structure of all ages of trees, it is not possible to plant an old woodland but it is possible to create similar conditions, by selective felling to create clearings and by leaving dead wood to provide habitats for the species that would exploit old, dying and dead trees
110
Why is provision of water important?
Providing water, such as a pond, will allow birds and mammals to drink, amphibians to breed and provide a habitat for aquatic plants and animals
111
Why is dissolved oxygen an important abiotic factor?
Lack of turbulence in slow moving rivers often produces low dissolved oxygen levels as less oxygen dissolves from the air, making a ricer narrower will increase flow rates and turbulence which allows more oxygen to dissolve
- this creates suitable conditions for fish such as trout and insect species such as mayfly larvae, both of which require high dissolved oxygen levels
112
Why is temperature an important abiotic factor?
Warm temperatures are needed for the development of the eggs of many species, areas of shallow water warm up rapidly and allow the eggs of fish, newts and frogs to develop more quickly
Clearings where vegetation has been removed provide warmer areas of soil or sand where lizards may lay their eggs
113
Why are light levels an important abiotic factor?
Most plants require specific light levels, creating clearings provides suitable conditions for the plants that need higher light levels, while retaining a dense tree canopy will provide the shaded conditions needed by other species
Light is essential for photosynthesis, most plants absorb blue or red light and most green passes through, however plants that live beneath the canopy often struggle to photosynthesise as the canopy has absorbed most of the red and blue light, so forest floor plants often have additional pigments like anthocyanins and carotenoids which can absorb other wavelengths of light
114
Why is pH an important abiotic factor?
Many plants cannot survive in acidic soils as there is often fire nitrogen-fixing bacteria which makes nitrates for growth
Many plants that do live in acidic soils capture insects which they digest to gain nitrogen nutrients
- a high or low pH can denature the proteins of the cells of exposed tissues such as lungs gills, and root hairs, low pH can also inhibit the production of calcium-based exoskeletons in organisms of calcium-based exoskeletons in organisms such as crustaceans
115
Why are mineral nutrients an important abiotic factor?
- some plants cannot survive live in nutrient deficient soils where there is less completion with taller plants
- they may not be able to compete in areas with fertile soils so the creation of a suitable habitat for these species may involve the removal of fertile topsoil or not adding fertilisers
116
Why is salinity an important abiotic factor?
Some aquatic species require water of a specific salinity
E.g. Opossum Shrimp are normally found in inter-tidal habitats which are more saline than freshwater but not as saline as seawater
Controlling the salinity of the water can increase population numbers and provide food for species higher up the tropic level
E.g. Dublin and Pied Avocet
117
Why is food an important biotic factor?
Survival of a species may be increased if suitable conditions are provided for its food species
E.g. wildflower grasslands that support seed eating birds
118
Why is control of predation important?
Will improve the survival of animals e.g. by providing island breeding sites for nesting water birds that cannot be reached by terrestrial predator such as foxes, if predators cannot be excluded they may be trapped or culled
Eradication of introduced mammal predators can be carried out
E.g. the Scilly isles where 3000 rats were killed to increase the breeding success of birds like the Manx Shearwater and Storm Petrel
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Why is control of competitors important?
Survival may be increased if competitor species are controlled
E.g. removing invasive rhododendron buses allows wildflowers to grow because they are not outcompeted for light
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Why is pollination important?
Many flowering plants need insects to pollinate their flowers so they can produce seeds, their attractive flowers attract pollinators like bees, wasps and butterflies that want their sugar-rich nectar
Helpful to have plants that flower at a range of times throughout the year so the pollinators always have something to pollinate
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Why is seed dispersal an important abiotic factor?
Some animal species are important to plants for the dispersal of their seeds, such as hippopotamus, forest elephants, seed-eating birds and many species of monkey
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Why is control of pathogens important?
Disease is a density dependent factor which can maintain the health of the surviving population by removing the weakest individuals
However introduced diseases can wipe out indigenous species that have no resistance to them
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Why is species re-introductions important?
It may be possibly to restore habitats that were changed by human activity, by re-creating more natural conditions
Many species will colonise these habitats naturally, especially more mobile species chuck as flying insects and birds
Other less mobile species may fail to cologne and may have to be re-introduced, especially any absent keystone species
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What are some examples of re-wilding?
Re-wilding in the Yellowstone National Park, USA:
- Gray Wolf was the top predator in the Rocky Mountains, but were exterminated in 1926, causing massive population changes in other species so were reintroduced in 1995, this caused big eco changes:
- deer populations declined so less young trees are killed
- more trees allowed for more beaver populations to increase
- dam that beavers create increased wetland areas
- wetland species have become more common
- overall biodiversity increased
Other species that have been successfully reintroduced include the Red Kite, white-tailed eagle, Eurasian otter, common crane, great bustard and the large blue butterfly
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Why is control of ecological succession - plagioclimax maintenance important?
Successful conservation of wildlife does not just involve establishing a habitat area and then protecting it, the natural changes that take place during ecological succession may reduce its value for the species that are present during any individual stage of succession.
Conservation programmes to protect plagioclimax communities include:
- hay meadows on Machair grassland on the Outer Hebrides in Scotland
- maintaining grazing marshes on the Broads National Park
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How does grazing help to protect species living in plagioclimax communities?
Prevents the establishment of taller plants and maintains a grassland plagioclimax, conservation grazing is often used to maintain habitats such as chalk grassland and flower-rich meadows
Trampling by livestock produces bare ground which is important for the germination of wildflower seeds and to produce the warmer clearing needed by some invertebrates and reptiles, animal dung can also support plant species
Different grazing species are used for different plagioclimax:
- sheep eat shorter grasses, some eat bushes and can be used to control invasive scrub
- ponies selectively eat grass and usually avoid flowering plants but they will eat invasive bracken which is avoided by most grazing animals
- cattle are good for removing long, rough grasses
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How does mowing help to protect species living in plagioclimax communities?
This removes the same vegetation that would be removed by grazing herbivores but it also removes the same vegetation that would be removed by grazing herbivores but it also removes the thorny, stinging, or bad tasting plants that herbivores have avoided
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How does burning help to protect species living in plagioclimax communities?
This can be used to remove vegetation that would not be eaten by grazing animals for example, mature heather bushes and young trees on heathland, creates the open, unshaded areas needed for the growth of young healthier plants that will re-establish the health land.
Heather seeds lie dormant in the soil until they are stimulated by the heat of the fire
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How does coppicing help to protect species living in plagioclimax communities?
Trees are cut to ground level every 3-30 years depending on the intended use of the harvested branches, so a coppiced woodland would be a patchwork of all different ages
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How does pollarding help to protect species living in plagioclimax communities?
Similar to coppicing but with branches cut above the height at which deer or livestock could eat the re-growing branches
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Why is population control important?
May be necessary to control the populations of selected species either but increasing or reducing them depending on which species are desirable, the release of captive bred individuals will boost the wild population and help to support the population of the population size is low, the breeding rate is low of the mortality rate is high
Predators or competition may be culled, trapped or removed
