Ecology theory is the study of interactions among plant, animal, microbial and abiotic factors within an ecosystem.Elements of this field include genetics, speciation, population dynamics, plant communities and predator/prey dynamics. The processes that relate to genetics include mutation, genetic drift and population bottlenecks. Within the interactions flora and fauna associations there are many types of mathematical models to explain the spatial relations and population dynamics of individual taxa. Besides models that depict the growth and decline, there are more specialized analyses which portray seed dispersal, migration patterns, symbioses and pollination. The abiotic factors of meteorology, soil and water chemistry are also vital in understanding the total ecological community.
The phenomena of autotrophism, herbivory and carnivory are intrinsic to ecology theory, in order to understand the complexity of the food web.Processes disease transmission and organism decay are further inherentelements;further, within the realm of ecology theory are the phenomena of habitat fragmentation, refugia and biological corridors;these larger scale features address the integrity of entire ecological communities and lead to strategies of conservation biology.
Deoxyribonucleic acid (DNA) is a long chain organic molecule that contains the coding for all metabolic and reproductive processes of all living organisms, save for certain...
Desert birdsLast Updated on 2013-10-29 21:52:31Deserts are challenging environments. Any organism that makes the desert its home must be able to cope with extreme temperatures and a scarce supply of water. Birds have the obvious advantage of flight which allows many of them to be only temporary visitors stopping off along their migrations, or seasonal inhabitants sticking around to breed during the more favorable seasons and leaving when things get too rough. There are a limited number of bird species that can truly call themselves desert dwellers, living primarily or only in such arid environments and not migrating. These birds possess some fascinating adaptations for dealing with life in the desert. (see: Adaptations of desert birds and mammals)
Organisms living in desert environments face several challenges including (1) obtaining and retaining water, (2) regulating their body temperature, and (3) obtaining and conserving... More »
HerbivoreLast Updated on 2013-10-24 16:24:24A herbivore is an animal that obtains its energy and nutrients by feeding on plants. Different types of herbivores eat different plant parts. For example, folivores feed on leaves, frugivores feed on fruits, granivores feed on seeds, pollinivores feed on pollen, and nectarivores feed on nectar. Herbivores can vary greatly in size, ranging from the largest terrestrial animals (elephants) and large marine mammals such as manatees and dugongs to small insects, nematodes and thrips. Herbivores are primary consumers (they receive their energy by consuming primary producers), so they play an important trophic role in ecological communities and food webs.
Because mature leaves are low in nutrients, and difficult to digest because of their high cellulose content, animals use many different strategies to eat leaves. Animals that feed on grass leaves are generally... More »
RefugiaLast Updated on 2013-10-21 15:07:19
Refugia (singular Refugium) are geographical locations where natural environmental conditions have remained relatively constant or stable during times of great environmental change, such as eras of glacial advance and retreat. Refugia protect populations of geographically isolated organisms which may then re-colonize a region when the wider environment returns to levels within the organism's tolerance levels. This idea is commonly referred to as The Refugia Theory.
Haffer (1969) first proposed the idea of refugia to explain the high diversity of Amazonian bird species seen today. Haffer (1969) proposed that the Amazon Basin paleoclimate experienced several warm, dry periods during episodes of continental glacier advance in the Pleistocene. These glacially driven periods led to the conversion of forest to savanna, which resulted in the isolation of small fragments of forest... More »
Desert biomeLast Updated on 2013-09-30 22:58:39
Desert biomes cover about one fifth of the Earth's surface and are defined to occur where rainfall is less than 50 centimeters (cm) per year. Although most deserts, such as the Sahara of North Africa and the deserts of the southwestern U.S., Mexico, and Australia, occur at low latitudes, another kind of desert, cold deserts, occur in the basin and range area of Utah and Nevada and in parts of western Asia. Most deserts have a considerable amount of specialized vegetation, as well as specialized vertebrate and invertebrate animals. Soils often have abundant nutrients because they need only water to become very productive and have little or no organic matter. Disturbances are common in the form of occasional fires or cold weather, and sudden, infrequent, but intense rains that cause flooding.
There are relatively few large mammals in deserts because most are not capable of... More »
Conservation and management of rare plant speciesLast Updated on 2013-09-18 20:23:33Over 8,000 plant species worldwide are threatened with extinction, according to the World Conservation Union, and that number grows daily. Researchers have recently estimated that between 22 and 47% of the world’s flora is in serious decline. In the United States alone, 744 plant species are federally listed as threatened or endangered by the U. S. Fish and Wildlife Service, comprising over half of all imperiled species. These are disturbing trends, because plants provide essential ecosystem services that sustain life on the planet: producing oxygen, sequestering carbon dioxide (a major greenhouse gas), and providing food, medicines, building materials, textiles, and habitat. Many plants listed as in danger are endemic (restricted in distribution) to small regions or require specialized habitats. However, an increasing number of formerly “common” or dominant species... More »
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