Threats to Biodiversity

Who are the key players in maintaining a healthy ecosystem?

Endemic species:

•a species that is native to a particular place and that is found only there.•Giraffes on the savannah•Polar bears in the Arctic•White-tailed Deer in Livingston

•Ecologists often use the numbers of endemic species of plants as an indicator of overall biodiversity because plants form the basis of ecosystems on land.

•Areas of the world with greater diversity also have large numbers of endemic species.

Giraffes on the African Savannah

Kangaroos and Koalas in Australia

Darwin’s finches are endemic to the Galapagos

Keystone Species:•“A species that is critical to the

functioning of the ecosystem in which it lives because it affects the survival and abundance of many other species in its community”

•Critical member of the ecosystem•Removal of this species could bring

collapse to the entire food web

Sea Otters Sea Urchins Kelp

Jaguars Top predators

Sea Stars Sea Urchins, Clams and Snails

Elephants destroy trees clearing land for savanna habitat

Beavers convert streams with dams to make marshes and swamps

Grizzly Bears Salmon Fertilizer??

Video- Why are bees disappearing?

http://www.ted.com/talks/marla_spivak_why_bees_are_disappearing.html

THREAT 1: Habitat Destruction

Threat 2: Poaching, Overhunting

Threat 3: Invasive Species• http://www.youtube.com/watch?v=iLH1qLCvqSg

What makes a Species Invasive?

• Non-native, or alien species- doesn’t belong in particular ecosystem

• Generalist- thrive in a wide range of habitats, reproduce quickly

• Few to no predators- can thrive unchecked• Outcompete endemic species for resources-

sunlight, food, space, water

Threat 4: Pollution

Threat 5: Over-Hunting and Over-Harvesting

Threat 6: Global Climate Change

Threat 6: Global Climate Change

• If fossil fuel emission trends continue, the world may be 6 deg. C warmer (11 deg F) by 2100 (IPCC)

• The Earth may lose 25% of all land species by 2100.

• If species cannot adapt, they go extinct• Other species may take their place,

including invasives