Threats to biodiversity Flashcards
What is over exploitation?
Overexploitation applies to a situation where individuals are being removed from a population at a greater rate than can be replaced by reproduction
What are the effects of over exploitation?
the species could become extinct from the area and the natural resource could be lost.
What is an example of over explotation?
overfishing
What is the bottleneck effect?
Evolutionary even in which a significant amount of the population or species is killed or prevented from reproducing
What is the effect of the bottleneck effect?
A bottleneck event results in a small population which may have lost some of its genetic variation. It is possible for the population to recover in numbers, however, this loss of genetic diversity effectively results in inbreeding which causes poor reproductive rates.
What is fragmentation?
Human activities can split up such areas, causing animals to lose both their natural habitat and the ability to move between regions of an ecosystem.
What are the effects of fragmentation?
populations can be isolated and thus interbreeding may be prevented leading to a decrease in genetic diversity.
Habitat fragments typically support lower species richness than a large area of the same habitat, thus reducing biodiversity. An additional issue is that habitat fragments suffer from degradation at their edges and this may further reduce their size.
One way to amend habitat fragmentation?
habitat corridors
What are benefits of habitat corridor?
colonisation: they allow animals to move and occupy new areas when food sources become scarce in their core habitat
migration: species can relocate seasonally without the need for human interference
interbreeding: animals can find new mates in neighbouring regions so that genetic diversity can increase within the population
What are non native species?
species are those that humans have moved either intentionally or accidentally to new geographical locations.
What is a naturalised species?
Those that become established within wild communities
What are invasive species?
Invasive species are naturalised species that spread rapidly and eliminate native species which can reduce species diversity
How can invasive species spread quickly?
Invasive species often fare better in the new environment due to lack of predators, parasites, pathogens and competitors that limit their population in their native habitat.
