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...
Habitat fragmentationLast Updated on 2015-07-04 14:10:43Habitat fragmentation involves alteration of habitat resulting in spatial separation of habitat units from a previous state of greater continuity.
Figure 1. Aerial photograph of dry forest scrub in southern Zambia, fragmented by agricultural land conversion. 2008. Source: C.Michael Hogan
This phenomenon occurs naturally on a geologic time-scale or in unusual and catastrophic events: however, since the Holocene era, humans have produced dramatic and swift transformation of landscapes throughout the world, resulting in a level of habitat fragmentation that has induced worldwide reduction in biodiversity and interuption of sustainable yields of natural resources.
Humans produce habitat fragmentation chiefly from agricultural land conversion, urbanization, pollution, deforestation and introduction of alien species; ironically, both human caused... More »
HerbivoreLast Updated on 2015-06-11 10:34:01A herbivore is an animal that derives 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 »
OverfishingLast Updated on 2014-12-07 17:22:32Overfishing is the human act of extracting aquatic (that is, marine and freshwater) fauna from natural water bodies at a rate greater than the reproductive and recruitment functions can replace that extraction. While there is some evidence that localized overfishing may have occurred in prehistoric eras, the bulk of overfishing has taken place in the last 150 years as the human population has expanded greatly and fishing technologies have enabled harvesting of many species at rates not imagined in earlier times. For over a century man's role in the depletion of certain regional fisheries has been noted. A functional definition of overfishing is sometimes given as the reduction in catch per unit effort by fishermen. Typically the concept of overfishing is linked to an individual aquatic species, and this issue is most often discussed within a specific marine or lacustrine province... More »
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 »
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