unit 3 KA8 - threats to biodiversity Flashcards
what is the impact of overexploitation on populations
populations can be reduced to a low level but may still recover
is it true that some species can have a naturally low genetic diversity but yet remain viable
yes
what is the bottleneck effect
small populations may lose the genetic variation necessary to enable evolutionary responses to environmental change
what can inbreeding result in
poor reproductive rates
is loss of genetic diversity critical for small populations?
yes
what has the clearing of habitats led to
habitat fragementation
what does the degradation of the edges of habitat fragments result in
increased competition between species as the fragment becomes smaller - which may result in a decrease in biodiversity
what do habitat corridors do
they allow movement of animals between fragments, increasing access to food and choice of mate. this may lead to recolonisation of small fragments after local extinctions
what canbe used to remedy widespread habitat fragemention
the isolated fragments can be linked with habitat corridors
what are introduced species
those that humans have moved either intentionally or accidentally to new geographic locations
what is another term for introduced species
non-native species
what are naturalised species
those that become established within wild communities
what are invasive species
naturalised species that spread rapidly and eliminate native species, therefore reducing species diversity.
what may invasive species be free of
- predators
- parasites
- pathogens
- competitors that limit there population in their native habitat
what may invasive species do to native species
prey on them, compete with them for resources, or hybridise with them
