Threats to Biodiversity Flashcards
What is overexploitation?
Resources are consumed at a faster rate than they can be replaced.
How does overexploitation affect a population?
Reduces the number in a population and reduces genetic diversity.
What causes a bottleneck effect?
An evolutionary event in which a significant percentage of a population (or species) is killed or prevented from reproducing.
What is the effect of the bottleneck effect?
Small populations may lose the genetic variation necessary to enable evolutionary responses to environmental change.
What is habitat fragmentation?
Separation of an organism’s preferred habitat.
What can cause habitat fragmentation?
Geological processes or human activity.
What does the degradation of the edges of a habitat fragment result in?
Increased competition between species due to smaller size - may result in a decrease in biodiversity and species diversity.
How can you improve habitat fragmentation?
Fragments can be linked with habitat corridors.
What are habitat corridors?
Pathways of natural habitat that allow movement of animals between them - increasing access to food and choice of mate. These lead to recolonisation.
What is the process a non-native species goes through when introduced to a new habitat?
Introduced > Naturalised > Invasive.
What are introduced species?
Non-native species that humans have moved (intentionally or accidentally) to new geographic locations.
What is a naturalised species?
Introduced species that have become established within wild communities.
What is an invasive species?
Naturalised species that spread rapidly and eliminate native species - reducing species diversity.
Why might humans introduce non-native species?
Biological control
Why might invasive species be successful in their new habitat?
Lack of natural predators, parasites, pathogens, and competitors.
