Biodiversity Outline

Only available on StudyMode
  • Download(s) : 53
  • Published : November 25, 2012
Open Document
Text Preview
I.Introduction
a.Over the past two decades, strong scientific evidence has emerged showing that loss of the world's biological diversity reduces the productivity and sustainability of natural ecosystems and decreases their ability to provide society with goods and services like food, wood, fodder, fertile soils, and protection from pests and disease. II.Body

a.[Amphibians] No group of animals has a higher rate of endangerment than amphibians. Scientists estimate that a third or more of all the roughly 6,300 known species of amphibians are at risk of extinction i.The current amphibian extinction rate may range from 25,039 to 45,474 times the background extinction rate ii.Frogs, toads, and salamanders are disappearing because of habitat loss, water and air pollution, climate change and disease. iii.Because of their sensitivity to environmental changes, vanishing amphibians should be viewed as the canary in the global coal mine, signaling subtle yet radical ecosystem changes that could ultimately claim many other species, including humans. b.[Birds] Birds occur in nearly every habitat on the planet and are often the most visible and familiar wildlife to people across the globe. As such, they provide an important bellwether for tracking changes to the biosphere. Declining bird populations across most to all habitats confirm that profound changes are occurring on our planet in response to human activities. i.A 2009 report on the state of birds in the United States found that 251 (31 percent) of the 800 species in the country are of conservation concern. ii.Globally, BirdLife International estimates that 12 percent of known 9,865 bird species are now considered threatened, with 192 species, or 2 percent, facing an “extremely high risk” of extinction in the wild — two more species than in 2008. iii.Habitat loss and degradation have caused most of the bird declines, but the impacts of invasive species and capture by collectors play a big role, too. c....
tracking img