3.3 Threats to Biodiversity

Human Activities Causing Species Extinctions

habitat destruction, introduction of invasive species, pollution, overharvesting, hunting and climate change

Factors for Red List

population size, degree of specialisation, distribution, reproductive potential and behaviour, geographic range and degree of fragmentation, quality of habitat, trophic level, probability of extinction

extinct

no longer survives on Earth

extinct in the wild

only survives in zoos or botanic gardens

Threatened

umbrella term for Critically Endangered, Endangered and Vulnerable species

Causes of Tropical Deforestation

Over-intensive shifting cultivation; Timber extraction; Over-collection of fuelwood for cooking and heating, and for making charcoal; Encroachment and clearance by landless peasant farmers; Clearance for pasture or crops, promoted by cheap land and government tax and financial incentives to encourage international investment - this includes Biofuels like Palm Oil and Sugar Cane