Biodiversity is the variation in living organisms, viewed within a given habitat, ecosystem or in the world as a whole. The concept is usually applied to the species diversity, although the notion of genetic biodiversity is applied to the variation in genes within an individual species. While most people think of rainforests as loci of great biodiversity, biomes such as oceans and grasslands are the likely repositories for even greater variation. Retention of diverse biota is important, since intact ecosystems are thought to be essential for provision of ecosystem services to humans, including maintenance of a diverse foodbank, pollination, clean water, flood control, pest control, waste decomposition, biomass energy resources and climate stability. Biodiversity is presently critical since we live in the era of the Mass Holocene Extinction, a period of species loss caused by man, and unrivaled in rate of species loss. Although the number of total species numbers in the tens of millions, most have not yet even been described. The extinction of a species is almost always related to destruction of habitat or man-made pollution.
The Spinner dolphin (Stenella longirostris), a marine mammal in the family of oceanic dolphins, engages in formation of small schools. This cetacean species evinces a dominance...
Arizona Mountains forestsLast Updated on 2013-12-10 10:46:49
The Arizona Mountain Forests extend from the Kaibab Plateau in northern Arizona to south of the Mogollon Plateau into portions of southwestern Mexico and eastern Arizona. This ecoregion is an element of the Temperate Coniferous Forests biome. The species richness in this ecoregion is moderate, with vertebrate taxa numbering 375 species. The topography consists chiefly of steep foothills and mountains, but includes some deeply dissected high plateaus. Elevations range from 1370 to 3000 meters (m) with some peaks as high as 3840 m. Soil types have not been well defined; however, most soils are entisols, with alfisols and inceptisols in upland areas. Stony terrain and rock outcrops occupy large areas on the mountains and foothills.
Vegetation zones in this ecoregion resemble the Rocky Mountain Life Zones but at higher elevations. Although forests in this ecoregion are too far south to... More »
Chihuahuan DesertLast Updated on 2013-12-06 23:07:07The Chihuahuan Desert encompasses one of the most biologically diverse arid regions on Earth. This ecoregion extends from within the United States south into Mexico. This desert is unique, as it has been sheltered from the influence of other arid regions such as the Sonoran Desert by the large mountain ranges of the Sierra Madres. This isolation has allowed the evolution of many endemic species; most notable is the high number of endemic plants; in fact, there are a total of 653 vertebrate taxa recorded in the Chihuahuan Desert. Moreover, this ecoregion also sustains some of the last extant populations of Mexican Prairie Dog, wild American Bison and Pronghorn Antelope.
Severe conservation pressures are on the Chihuahuan Desert. On the Mexico side, there are destructive activities from illegal poaching, habitat destruction from illegal drug trafficking and large scale movements of... More »
California coastal sage and chaparralLast Updated on 2013-12-05 20:18:34
The California coastal sage and chaparral ecoregion, located along the southern and central coast of California, has extremely high levels of species diversity and endemism. The coastal sage scrub is an endangered ecosystem that contains a number of endangered species. The California Gnatcatcher is currently being used as an umbrella species to protect the endemic flora and fauna of this region from urban development. The region is listed as an Endemic Bird Area with a large number of endemic scrub species. Generally located on high value coastal zone real estate and threatened by land development, the ecoregion represents the struggle between ecological preservation and human development.
The California coastal sage and chaparral encompasses coastal terraces, plains, and foothills along the Pacific coast of northwestern Mexico and southern California, USA. The Santa Rosa Mountains... More »
Cuban moist forestsLast Updated on 2013-12-05 19:18:08The Cuban moist forests originally held exceptionally distinctive insular flora and fauna, with many species, genera and families unique to its forests in the form of relict taxons. The island’s long-standing isolation has made it possible for these relict taxons to speciate, and many unique groups have also diversified. Many of the old lines that survive in these forests are extinct on the nearby continents. The rich flora and diverse fauna should be pointed out, particularly land snails. At present, these forests are mostly destroyed and fragmented. Expansion in the production of cacao, coffee and tobacco as well as mining and other human activities represent a serious threat in some areas.
Originally, this ecoregion was distributed in multiple patches of different sizes along the ranges and highlands of the island of Cuba (located between 19º50’N to... More »
Costa Rican seasonal moist forestsLast Updated on 2013-12-05 17:53:35The Costa Rican seasonal moist forests ecoregion is quite different from the surrounding dry and moist forest habitat types. Deciduous trees that shed leaves during the distinct dry season make up the dominant vegetation in these forests. The ecoregion fauna have a moderate species richness, with the number of vertebrates occurring here amounting to 698 taxa; however, faunal endemism is rather low. The flora are more adapted and capable of surviving in such a seasonally based ecoregion. Animals also are adapted to this fluctuation between wet and dry climate changes, and the subsequent changes in the plantlife.
The natural environment of this ecoregion has been substantially destroyed, chiefly by deforestation by the Costa Rican and Nicaraguan people, to clear land for grazing of livestock and other agricultural uses. Disruption to the Nicaragua portion of the ecoregion has also... More »
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