Threats Of Biodiversity Flashcards
The threats to biodiversity
Exploitation and recovery of populations and the impact on their genetic diversity.
What happens with overexploitation?
With overexploitation, populations can be reduced to a low level but may still recover.
What happens with some species?
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 happens when their is a loss of genetic diversity in small populations?
In small populations, this loss of genetic diversity can be critical for many species, as inbreeding can result in poor reproductive rates.
What has the clearing of habitats lead to?
Lead to habitat fragmentation
Degradation of the edges of habitat fragments…
Results in increased competition between species as the fragment becomes smaller. This results in decrease of biodiversity.
More isolated fragments…
And smaller fragments exhibit a lower species diversity.
To remedy…
Widespread habitat fragmentation, isolated fragments can be linked with habitat corridors.
What do habitat corridors allow?
The corridors allow movement of animals between fragments, increasing access to food and choice of mate.
What can habitat corridors lead to?
May lead to recolonisation of small fragments after local extinctions.
What is introduced species?
Introduced (non native) species are those that humans have moved either intentionally or accidentally to new geographic locations.
What is the term given to those that are established in the wild?
Naturalised species
What are invasive species?
Invasive species are naturalised species that spread rapidly and eliminate native species, therefore reducing species diversity.
What are invasive species free of?
The predators, parasites, pathogens and competitors that limit their population in their native habitat.
