BIOL 1442 Ch 47 Threats to Biodiversity

The core threat to biodiversity is the combination of

human population growth and resource exploitation

The three greatest proximate threats to biodiversity are

habitat loss, overharvesting, and the introduction of exotic species

Humans rely on technology to modify

their environment and replace certain functions that were once performed by the natural ecosystem

endemism

species unique to a defined geographic location

Modifications to rivers include

dams, levees, dredging, and rerouting

Overharvesting is a serious threat in particular to

aquatic species

tragedy of the commons

no fisher has a motivation to exercise restraint in harvesting a fishery when it is not owned by that fisher

The overexploitation is fisheries is exacerbated when

access to the fishery is open and unregulated and when technology gives fishers the ability to overfish

coral reefs are extremely diverse marine ecosystems that face

immediate peril from several processes

Bush meat

generic term for wild animals killed for food

Hunting practices in specifically Africa and parts of Asia are believed to

threaten a number of species with extinction

Species threatened by the bush meat trade are mostly

mammals including many primates in the Congo basin

Exotic species

species that have been intentionally or unintentionally introduced into an ecosystem in which they did not evolve

Lakes and islands are particularly vulnerable to extinction threats from

introduced species

Global decline in amphibian species is caused by

the fungus Batrachochytrium dendrobatidis, which causes the disease chytridiomycosis

Geomyces destructans is responsible for

white-nose syndrom, which infects cave-hibernating bats in eastern North America and has spread from a point of origin in western New York State

Climate change caused by humans has led to an

escalating warming trend that is a major extinction threat

The warming trend will shift colder climates towards the ( ) forcing species to ( )

north and south poles; move with their adapted climate norms while facing habitat gaps along the way

Climate gradients will also move up mountains, eventually

crowding species higher in altitude and eliminating the habitat for those species adapted to the highest elevations

global warming will raise ocean levels due to

meltwater from glaciers and the greater volume of warmer water