Download
1 / 7
70 likes | 249 Views
Science (2005) 309:90. We really don’t have a satisfying answer to this fundamental question. Biodiversity hotspots for tropical rain forest and chaparral ecosystems. There are Biodiversity “Hotspots”.
E N D
Science (2005) 309:90 We really don’t have a satisfying answer to this fundamental question.
Biodiversity hotspots for tropical rain forest and chaparral ecosystems. There are Biodiversity “Hotspots” Less than 1% of Earth’s surface supports 20% of known plant species and probably a greater portion of animal species. Biodiversity hotspots are significant for conservation plans.
Biodiversity is Being Lost Rapidly Through Extinction How rapid is the current rate of extinction? The number’s hard to pin down, but generally accepted estimates put it at 10-100 times the rate before extensive human–induced environmental modifications. For example, in the U.S. ~ 225 vascular plant species have become extinct in the past 50 years and about 650 of the remaining 20,000 species are threatened.
Dire News Not all agree that we’re seeing a mass extinction, but it’s clear species loss has accelerated sharply above background.
Effect of rabbit introduction Australia What are the Causes of Accelerated Extinction? Habitat loss Pollution Overharvesting Introduction of exotic species and diseases Climate change These factors often work in combination to eliminate species
What’s the Minimum Level of Biodiversity to Preserve? There are two ways to view this question: What’s the minimum level of biodiversity to maintain the quality of our emotional, cultural, and spiritual lives? What’s the minimum level of biodiversity to maintain human populations? We either have widely differing views for the first question or don’t know at all for the second question.
