Biomes are the composite of all species within a large scale ecological community. In the natural environment, these assemblies have typically co-evolved, so that they have a natural arrangement in terms of their positioning to compete for sunlight, water and nutrient resources; in some cases these associations are symbiotic, but in most cases they are simply optimal spatial arrangements to take advantage of all the resources available in a given habitat. For example, there is typically a vertical tiering, where plants of differing light requirements can occupy canopy, mid-level or forest floor niches; the same theory applies even in a grassland, where the canopy is simply the tallest of the grasses or herbs.
In the case of water competition, depth of rooting and tolerance to arid soils are chief determinants for spatial arrangement; as far as nutrient competition, plants will compete to determine the most robust competitor for a given edaphic niche. While the outcome geometry for the plant palette usually appears random, there is a complex network of ecological theory at work that determines the layout of the assembled community. The same concept applies to aquatic communities as to terrestrial systems, with some plants having immersed roots and others, either macrophytes or phytoplankton, floating or immersed at varying levels suitable for their sunlight needs.
WWF Terrestrial Ecoregions Collection
The Iberian sclerophyllous and semi-deciduous forests support a complex and diverse flora with a notable...
BiogeographyLast Updated on 2014-11-30 22:10:52Biogeography is the study of the spatial distribution of biological organisms. The scale of analysis ranges from very small micro-topography regimes to continental dimensions. Fundamental concepts in this field of study are the nature of barrier formation and response of species in their patterns of travel and migration; in particular, the presence of rivers, mountain ranges, deserts and other natural boundaries are examples of large scale barriers. Besides such major landform barriers, there are soil, topographic and meteorological factors that influence the distribution of each species. In the case of smaller scale regimes that are applicable for some bacteria or limited range plant species, there are often very restricted niches; for example, certain bacteria extremophiles may be limited to such localized features as small geyser pools, and some rare plants may have a single extant... More »
BiomeLast Updated on 2014-11-30 22:01:13Biomes organize the biological communities of the earth based on similarities in the dominant vegetation, climate, geographic location, and other characteristics. Aspects of the physical environment such as precipitation, temperature, and water depth, have a strong influence on the traits of species living in that natural environment, and thus biological communities experiencing similar environmental conditions often contain species that have evolved similar characteristics. There is no single classification of biomes that is agreed upon by all scientists because different scientists wish to emphasize different characteristics by their definition. Historically however, biomes have been identified and mapped based on general differences in vegetation type associated with regional variations in climate and terrain.
Terrestrial biomes characterize ecosystems on land, and are usually... More »
Biological corridorLast Updated on 2014-11-30 21:27:13
Biological corridor is the designation for a continuous geographic extent of habitat linking ecosystems, either spatially or functionally; such a link restores or conserves the connection between habitats that are fragmented by natural causes or human development. Such corridors are an important aspect in the preservation of species richness and biodiversity. There are different scales of biological corridors, but all share the same purpose of providing connections for species through fragmented landscapes. A biological corridor, alternatively termed habitat corridor, is used for the transportation functions of fauna and seed dispersal/propagation routes for flora and lower life forms. Specific elements of this transport for fauna include seasonal or migration movement, life cycle links, species dispersal, re-colonization of an area and movement in... More »
DeforestationLast Updated on 2014-11-09 17:48:51Deforestation is the destruction or clearing of forested lands, usually for the purposes of expanding agricultural land or for timber harvesting. When the process is conducted by clearcutting (removal of most or all of the canopy tree growth, leaving few or no live or dead trees standing) or when mass forest burning occurs, significant losses of habitat and biodiversity may result, including the erosion of biological community structure and the extinction of species. Deforestation is proceeding at a rapid pace in may areas of the world, especially in the tropical and boreal forest regions of the earth, with annual net loss of forests during the 1990s estimated in the range of nine to sixteen million hectares per annum. Large scale deforestation may have adverse impacts on biosequestration of atmospheric carbon dioxide, exacerbating greenhouse gas buildup, through the release of stored... More »
PlantLast Updated on 2014-10-28 12:04:37
A plant is any one of the vast number of organisms within the biological kingdom Plantae; in general, these species are considered of limited motility and generally manufacture their own food. They include a host of familiar organisms including trees, forbs, shrubs, grasses, vines, ferns, and mosses. Conventionally the term plant implies a taxon with characteristics of multicellularity, cell structure with walls containing cellulose, and organisms capable of photosynthesis. Modern classification schemes are driven by somewhat rigid categorizations inherent in DNA and common ancestry.
Throughout most of the history of science from Aristotle to Linnaeus and into the 20th century, species were divided into two kingdoms: animals and plants. Driven by DNA characterizations and other modern analysis, fungi and bacteria have now been removed to separate kingdoms; in particular,... More »
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