Topic 8: Threats to Biodiversity Flashcards
What is exploitation?
The harvesting of a species
What happens in over exploitation?
Populations can be reduced to low level, genetic diversity will fall
Is recovery possible in over exploitation?
Recovery is possible and the population may increase after harvesting pressure is reduced, genetic diversity may increase
What is the bottleneck effect?
Where small populations lose the genetic variation necessary to enable evolutionary responses to environmental change
In small populations, the loss of genetic diversity (bottleneck effect) can be _____
critical
What does inbreeding result in?
Poor reproductive rates
What has clearing of habitats led to?
Habitat fragmentation
Habitat fragments support lower species richness than a large fragment ___________
of the same area
Habitat fragments suffer degradation at the ridges which ___________
reduces their effective size
What does degradation of, the edges of habitat fragments result in?
A decrease in biodiversity
More isolated fragments and smaller fragments exhibit _____________
a lower species diversity
How can widespread habitat fragmentation be resolved?
Isolated fragments can be linked with habitat corridors
How are habitat corridors beneficial?
Increase access to food and choice of mate by allowing movement of animals between fragments
What may habitat corridors lead to?
Re-colonisation of small fragments after local extinctions
What is an introduced (non-native) species?
A species that humans have moved intentionally or accidentally to new geographic locations
