3.8 threats to biodiversity Flashcards
Define exploitation
-when people are using and benefiting from resources
Define overexploitation
-when populations are reduced to a low level but may still be able to recover
State what the bottleneck effect is
-bottle neck event (causes a bottle neck population) drastically reduced the size of a population
What events may abuse a bottleneck population
- environmental disaster
- hunting of a species to the point of extinction
- habitat destruction resulting in deaths of organisms
what may happen to a small population in the loss of genetic diversity
- lose variation essential to enable evolutionary responses to any change in the environment
- inbreedingr
Define habitat fragmentation
-instead of a habitat being in one area, they are split into smaller sections (fragments)
What is the effect of habitat fragmentation
- interior fragment decreases
- biodiversity decreases
- competition between species increases
- decrease species diversity
State what a habitat corridor is
-a link/connection of different habitat fragments
What is the benefit of a habitat corridor
- allows animals to move between different fragments
- increases different food
- increases choice of mate
- can lead to recolonisation
Define species introduction
- introduction of a non native species in a new geographic location
- can be intentional or acccidental
Define a naturalised soecies
-if a species becomes well established within wild communities n is now within
Define invasive species
-a naturalised species that spreads rapidly and starts to eliminate natives and reduces species diversity
What is a feature of being an invasive species
-they may be free of anything that usually limits their population (predators, competitors, parasites)
How does an invasive species effect native species
- lower the number of natives;
- preying on native species, outcompeting natives or hybridising with the natives
