Threats to Biodiversity Flashcards
What’s the impact of overexploitation?
Populations can be reduced to a low level but may still recover.
Some species have a naturally low genetic diversity in their population and yet remain viable.
What is the bottleneck effect?
Small populations may lose the genetic variation necessary to enable evolutionary responses to environmental change.
What impact does the bottleneck effect have on small populations?
This loss of genetic diversity can be critical for many species as interbreeding can result in poor reproduction rates.
What leads to habitat fragmentation?
The clearing of habitats.
What’s the impact of habitat fragmentation?
Degradation of the edges of habitat fragments results in increased competition between species as the fragment becomes smaller. This may result in a decrease in biodiversity.
More isolated fragments and smaller fragments exhibit a lower species diversity.
How do you fix habitat fragmentation?
Isolated fragments can be limited with habitat corridors.
The corridors allows movement of animals between fragments, increasing access to food and choice of mate. This may lead to recolonisation of small fragments after local extinctions.
What are introduced species?
Species that humans have moved either intentionally or accidentally to new geographic locations.
What are naturalised species?
Species that become established within wild communities.
What are invasive species?
Naturalised species that spread rapidly and eliminate native species, therefore reducing species diversity.
Invasive species may well be free of the predators, parasites, pathogens and competitors that limit their population in their native habitat.
Invasive species may prey on native species, outcompete them for resources or hybridise with them.
