Biodiversity and Conservation: Biodiversity Crisis

Biodiversity

Includes all living things

1,000-10,000

How many times faster current extinction rates are than the natural rate

1,000

Number of species that are known to have gone extinct in the last 400 years

Doubled

Rate at which the human population has increased since 1970

Tropical forests

Contain some of the greatest concentration of species and are being destroyed at an alarming rate

Genetic diversity

Comprises of population size and genetic variation over time; much harder to recover when lost than population size

Three levels of biodiversity

Genetic diversity, species diversity, and ecosystem diversity

Ecosystem diversity

The local extinction of one species can have a negative impact on another species in an ecosystem

Assessment

Critical to our understanding of species responses to environmental change; is used to determine changes in geographic distribution, population size, population connectivity, and life history atributes

Traits of species at risk of going extinct

Low population density, small geographic range, specialized niche, low reproductive rates

Major threats to biodiversity

Habitat destruction, introduced species, overharvesting, and global climate change

Habitat loss

Human alteration of habitat is the greatest threat to biodiversity, usually through habitat fragmentation or destruction

Introduced species

Species that humans move from a native location to a new geographic region; without natural predators, parasites, and pathogens, they spread rapidly and disrupt the adopted community

Overharvesting

Human harvesting of wild plants and animals at rates exceeding the ability of populations to recover; large animals with low reproductive rates are especially vulnerable

Climate change

A crucial underlying factor that helps to drive extinction around the world