Key Area 3.8 Threats To Biodiversity Flashcards
What is over exploitation?
Resources being consumed at a rate greater than can be replaced.
Can species recover after over exploitation?
Yes- if the exploitation is halted.
What is the bottleneck effect?
When small populations loose the genetic variation necessary to enable evolutionary responses to environmental change. Inbreeding in small populations results in poor reproductive rates.
What has clearing of habitats lead to?
Habitat fragmentation.
What does degradation at the edges of habitat fragmentation’s result in?
Increased competition between species.
What is a solution to habitat fragmentation?
Linking isolated habitat fragments can be linked by habitat corridors.
What do habitat corridors allow?
The movement of animals between fragments to find mates or to access food.
What could habitat corridors do?
Recolonise small fragments after local extinction.
What is an introduced species?
A species which humans have moved either internationally or accidentally to a new geographical location.
What is a naturalised species?
An introduced species which become established within wild communities.
What is an invasive species?
A naturalised species which spread rapidly and eliminate native species, therefore reducing species diversity.
What allows invasive species to spread rapidly?
They are free of predators, parasites, pathogens, and competitors.
How do invasive species eliminate native species?
They prey on them, out compete them, or hybridise with them.
What are some examples of invasive species?
Cane toad,
Grey squirrel,
Japannees knotweed,
Rhododendron.
