Threats To Biodiversity Flashcards
What is direct exploitation
When a population has declined as it is exploited for a wide range of products or is considered to be harmful
How are species directly exploited for food
Species have been overexploited to provide food for humans i.e. cattle, sheep, growing crops
What are some examples of species are currently overexploited for human consumption
Cod, swordfish, tuna, many sharks, and many herbivores (cattle, sheep, chickens)
What species have been made extinct due to over exploitation for food
The dodo, great Auk, And the passenger pigeon
How are animals overexploited for fashion
Fur coats and accessories
 leather bags and shoes
What sort of animal is exploited for fur coats and accessories
Leopard, snow leopard, ocelot, tiger, fur seals
How are seal populations affected by the fashion industry
We’re nearly hunted to extinction their skins in the 1900s
What animals are used for leather bags and shoes
Crocodiles and alligators
What sort of wild animals people keep as pets
Parrots, lizards, Snakes, tortoises, Tropical fish
How have Zoos contribute to over exploitation of animals For pets and entertainment
Used to be common to collect wild animals for zoo collections now only Occurs for conservation reasons (increase gene pool)
What is the problem with Aquaria and keeping fish
Marine fish are difficult to keep in captivity because of conditions they require not understood
What is the example of a marine fish that shouldn’t be kept in captivity
The Banggai Cardinal fish is endemic to the Banggai Islands of Indonesia is it in made endangered due to collection from the wild
How is nature overexploited for furniture and ornaments
A lot of furniture is made with timber from tropical rainforests, black piano keys were made of ebony wood and white Keys made of elephant ivory, coral and seashells as tourist souvenirs
What are some examples of tropical trees used for furniture
Mahogany, teak and Ramin
Why are traditional medicines are contributed to overexploitation
Demand for traditional medicines especially in Asia has led to large numbers of selected species being collected
Why are traditional medicines problematic
Little scientific evidence that they are effective as medicines
What type of animals are used in traditional medicines
Tigers, rhinoceros, seahorses
What sort of things can traditional medicine with tiger in it be used to cure
Claws as a sedative, Tail for skin diseases, dung for alcoholism And whiskers for toothache
What “other products” are Directly exploited from nature
Oil from Whale blubber and spermaceti from the heads of sperm whales
What was whale blubber and spermaceti used for
Manufacture products such as lamp oil, candles, soap, lubricating oil, cosmetics and perfume
Why have many species been eradicated by humans?
They threaten humans or interfere with human activities
What sort of species are eradicated because they threaten humans?
Sharks
Poisonous snakes
Crocodiles
What are some pathogen vectors (disease carriers)?
Malaria mosquitoes
Tsetse flies
What are some predators of livestock?
Wolves
Puma
Lion s
Birds of prey
Herons
Seals
What are some agricultural pests
Insects
Fungi
Birds
Molluscs
What are some wild herbivores that eat crops//compete with livestock
Rabbits
Deer
What are some forestry pests?
Wood-boring beetles
Deer
Squirrels
Beavers
How can humans affect water availability?
Land drainage- affected large wetland, over exploitations of groundwater (lowering water table), HEP schemes may cause sudden change in water levels flooding river side nests ad killing eggs
How do humans reduce the levels of dissolved oxygen in water?
Reduced by hot water discharges from power stations or by discharging organic waste which deoxygenates the water as it decomposes
What negative impacts does reduced dissolved oxygen have?
Reduce the survival of aerobic organisms such as fish and insect larvae
What sort of plants are found in anaerobic soil?
The sundew in marshland where there isn’t any competition
Why can most plants not survive in anaerobic soil?
Have low nitrogen levels so large plants with high nitrogen demands cannot live there
How does the SUNDEW get its nitrogen?
Trapping and directing insects
How is the SUNDEW affected by land drainage?
Produce more aerobic soils may allow taller competitors to colonise that area causing the SUNDEW to die out
How will changing temperature affect wildlife species
species that are able to adapt to changing conditions will thrive while those that cannot will die out
How will global climate change Affect species
Will cause changes in the distribution of species as they colonised areas which become more suitable or die out In areas they can no longer survive

How might hot effluent water affect species
Increasing water temperature can increase the growth rate of aquatic vegetation, providing more food for aquatic animals, or it may increase the rate of decomposition Causing deoxygenation
How can humans affect PH?
pollutant gases from Burning fossil fuels, smelting metals produces acidic conditions, removing of crops
What is the problem with acidic conditions
Can denature the cell proteins of exposed tissues
What species are particularly vulnerable to acidic conditions
Fish eggs and gills, invertebrates with calcium based exoskeletons such as crayfish
How can humans affect water turbidity
Activities such as ploughing mining or dredging mean increase water turbidity
What is the problem with increased water turbidity
Reduce light penetration and prevent submerged aquatic plants from photosynthesising
Can also kill filter feeding organisms as the gills become blocked
How can humans cause physical damage to species
Discarding litter or old fishing gear
Why are pollinators so important
Many plants pollen is transported between the flowers by insects
What would happen if insects died out
The plants would not be able to reproduce
What is reducing the population of many pollinators
Use of pesticides, loss of wild flowering plants
What is an example of a pollinator
The bee
 And what sort of animals are Able to disperse seeds
Large herbivores such as elephants, rhinos, hippos, gorillas And many monkey species
What are seed dispersal species
Animals that eat seeds and fruit
Why are elephants good at seed dispersal
Unlike most large animal herbivores they are not ruminants so they did not repeatedly chew their food which would destroy the seeds they are also not territorial so they spread Seeds over a larger area than most herbivores
How can overexploitation affect food chain
Over exploitation of one species may cause an increase of another
What is an example of a food chain Impact
Overcollection of turtle eggs causes a decline in turtle numbers and therefore increasing their food species I. E. jellyfish
What is an introduced species
Non-native species has introduced to an area where it may have a greater chance of survival over the native species
What is an example of an introduced competitor
The grey screw was introduced to the UK from North America it is outcompeted the red squirrel in many areas
Why did the grey squirrel outcompete the red squirrel
It can digest acorns from out trees which the red squirrel cannot it is also larger and can compete more successfully for nest sites
What is the problem with rhododendrons
They are very invasive and being Evergreen they shade the ground and prevent the regrowth of native Vegetation they also release toxins that inhibit the growth of other plants
How can a ships ballast water introduced species
Cargo ships often carry ballast water when there is no cargo on board it may be hung down board and one part of the ocean and then introduce non-indigenous species in to other areas when it’s pumped overboard
Why are introduced predators a problem
Reduce population of native wildlife especially when it’s not adapted to survive in the presence of predators
How is the European water vole been impacted by an introduced predator
Population reduced due to the American mink That escape from fur farms
How are ground nesting birds on many oceanic islands affected by introduced predators
Introduction of cats, rats, pigs and dogs which can destroy nests and kill birds
How can pathogens be introduced to a new environment
Humans made reduce pathogens or might be carried by introduced species
How did the grey squirrel introduce a pathogen
Brought squirrel pox which does not kill the grey squirrel but it does kill the indigenous red squirrel
What is species hybridisation
If you introduced species is very close to you related to an indigenous species in crossbreeding may produce fertile hybrids
What is an example of hybridisation
The red deer which is indigenous to the UK best friend by harmonisation with the introduce sika deer
 Whats an example of how a species creates abiotic factors
African elephants create Cleveland in water holes that many other species rely on for water
What sort of human activities cause habitat destruction
Deforestation
Ploughing of grassland
Reservoir creation
Mineral extraction (opencast mining)
Urban expansion
