3.8 Threats to Biodiversity Flashcards
What is the difference between exploitation and overexploitation?
Exploitation is the act of exploiting an ecosystem for personal benefit.
Over exploitation is exploitation where the individuals are being removed faster than the reproduction rate.
Why do small populations have poor reproductive rates?
Lack of genetic variation and inbreeding
Describe the bottleneck effect
This is where the majority of the population die out in a chance event (such as natural disaster) and genetic variation necessary to enable evolutionary responses to environmental change is lost.
What is the effect of bottleneck effect on populations?
It leaves the survivors with low genetic diversity meaning they do not have not the variation to adapt to environmental changes
Give an example of a population who were nearly drove to extinction by over exploitation
Cod
What are some human causes of habitat fragmentation?
Deforestation
Urbanisation
Building of Roads
Describe ‘Habitat Fragmentation’
Habitat is broken up into fragments by geographical processes or human activity
What happens to the animals as habitat fragmentation occurs?
Results in increased competition between species as the fragments become smaller.
How does habitat fragmentation affect biodiversity
Species in very isolated and small habitat fragments exhibit a lower species diversity
What is a solution to habitat fragmentation/
Using Habitat corridors to relink ecosystems
Define ‘habitat corridors’
Area of habitat connecting previously separated populations
What do habitat corridors allow for?
Allow species to feed, mate and recolonise habitats
Define an introduced species?
Species that has been moved either intentionally or accidentally to a new geographic location
What is a ‘Naturalised’ species?
A species that has became established within wild communities
Define an ‘Invasive species’?
An invasive species is a species that spreads rapidly and eliminate native species
