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Metacommunity
An ecological metacommunity is a set of interacting communities which are linked by the dispersal of multiple, potentially interacting species. The term is derived from the field of community ecology, which is primarily concerned with patterns of species distribution, abundance and interactions. Metacommunity ecology combines the importance of local factors (environmental conditions, competition, predation) and regional factors (dispersal of individuals, immigration, emigration) to explain patterns of species distributions that happen in different spatial scales. There are four theoretical frameworks, or unifying themes, that each detail specific mechanistic processes useful for predicting empirical community patterns. These are the patch dynamics, species sorting, source–sink dynamics (or mass effect) and neutral model frameworks. Patch dynamics models describe species composition among multiple, identical patches, such as islands. In this framework, species are able to pe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unified Neutral Theory Of Biodiversity
The unified neutral theory of biodiversity and biogeography (here "Unified Theory" or "UNTB") is a theory and the title of a monograph by ecologist Stephen P. Hubbell. It aims to explain the diversity and relative abundance of species in ecological communities. Like other neutral theories of ecology, Hubbell assumes that the differences between members of an ecological community of trophically similar species are "neutral", or irrelevant to their success. This implies that niche differences do not influence abundance and the abundance of each species follows a random walk. The theory has sparked controversy, and some authors consider it a more complex version of other null models that fit the data better. "Neutrality" means that at a given trophic level in a food web, species are equivalent in birth rates, death rates, dispersal rates and speciation rates, when measured on a per-capita basis. This can be considered a null hypothesis to niche theory. Hubbell built on ear ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Species Sorting
Species sorting is a mechanism in the metacommunity framework of ecology whereby species distributions and abundances can be related to the environmental or biotic conditions in a particular habitat. The species sorting paradigm describes a system of habitat patches with different environmental conditions that organisms can move between. Species are able to disperse to patches with suitable environmental conditions, resulting in patterns where environmental conditions can predict the species found in a particular habitat In ecology, the term habitat summarises the array of resources, physical and biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species habitat can be seen as the physical .... References {{Reflist Ecology ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Source–sink Dynamics
Source–sink dynamics is a theoretical model used by ecologists to describe how variation in habitat quality may affect the population growth or decline of organisms. Since quality is likely to vary among patches of habitat, it is important to consider how a low quality patch might affect a population. In this model, organisms occupy two patches of habitat. One patch, the source, is a high quality habitat that on average allows the population to increase. The second patch, the sink, is very low quality habitat that, on its own, would not be able to support a population. However, if the excess of individuals produced in the source frequently moves to the sink, the sink population can persist indefinitely. Organisms are generally assumed to be able to distinguish between high and low quality habitat, and to prefer high quality habitat. However, ecological trap theory describes the reasons why organisms may actually prefer sink patches over source patches. Finally, the source- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Community (ecology)
In ecology, a community is a group or association of populations of two or more different species occupying the same geographical area at the same time, also known as a biocoenosis, biotic community, biological community, ecological community, or life assemblage. The term community has a variety of uses. In its simplest form it refers to groups of organisms in a specific place or time, for example, "the fish community of Lake Ontario before industrialization". Community ecology or synecology is the study of the interactions between species in communities on many spatial and temporal scales, including the distribution, structure, abundance, demography, and interactions between coexisting populations. The primary focus of community ecology is on the interactions between populations as determined by specific genotypic and phenotypic characteristics. Community ecology also takes into account abiotic factors that influence species distributions or interactions (e.g. annual tempe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Community Ecology
In ecology, a community is a group or association of populations of two or more different species occupying the same geographical area at the same time, also known as a biocoenosis, biotic community, biological community, ecological community, or life assemblage. The term community has a variety of uses. In its simplest form it refers to groups of organisms in a specific place or time, for example, "the fish community of Lake Ontario before industrialization". Community ecology or synecology is the study of the interactions between species in communities on many spatial and temporal scales, including the distribution, structure, abundance, demography, and interactions between coexisting populations. The primary focus of community ecology is on the interactions between populations as determined by specific genotypic and phenotypic characteristics. Community ecology also takes into account abiotic factors that influence species distributions or interactions (e.g. annual temper ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ecological
Ecology () is the study of the relationships between living organisms, including humans, and their physical environment. Ecology considers organisms at the individual, population, community, ecosystem, and biosphere level. Ecology overlaps with the closely related sciences of biogeography, evolutionary biology, genetics, ethology, and natural history. Ecology is a branch of biology, and it is not synonymous with environmentalism. Among other things, ecology is the study of: * The abundance, biomass, and distribution of organisms in the context of the environment * Life processes, antifragility, interactions, and adaptations * The movement of materials and energy through living communities * The successional development of ecosystems * Cooperation, competition, and predation within and between species * Patterns of biodiversity and its effect on ecosystem processes Ecology has practical applications in conservation biology, wetland management, natural resource management ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Patch Dynamics
Patch dynamics is an ecological perspective that the structure, function, and dynamics of ecological systems can be understood through studying their interactive patches. Patch dynamics, as a term, may also refer to the spatiotemporal changes within and among patches that make up a landscape. Patch dynamics is ubiquitous in terrestrial and aquatic systems across organizational levels and spatial scales. From a patch dynamics perspective, populations, communities, ecosystems, and landscapes may all be studied effectively as mosaics of patches that differ in size, shape, composition, history, and boundary characteristics. The idea of patch dynamics dates back to the 1940s when plant ecologists studied the structure and dynamics of vegetation in terms of the interactive patches that it comprises. A mathematical theory of patch dynamics was developed by Simon Levin and Robert Paine in the 1970s, originally to describe the pattern and dynamics of an intertidal community as a patc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Species Composition
Species richness is the number of different species represented in an community (ecology), ecological community, landscape or region. Species richness is simply a count of species, and it does not take into account the Abundance (ecology), abundances of the species or their Relative species abundance, relative abundance distributions. Species richness is sometimes considered synonymous with species diversity, but the formal metric species diversity takes into account both species richness and species evenness. Sampling considerations Depending on the purposes of quantifying species richness, the individuals can be Forest inventory#Simple random sampling, selected in different ways. They can be, for example, trees found in an forest inventory, inventory plot, birds observed from a monitoring point, or beetles collected in a pitfall trap. Once the set of individuals has been defined, its species richness can be exactly quantified, provided the species-level Taxonomy (biology), taxo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Robert MacArthur
Robert Helmer MacArthur (April 7, 1930 – November 1, 1972) was a Canadian-born American ecologist who made a major impact on many areas of community and population ecology. Early life and education MacArthur was born in Toronto, Ontario, to John Wood MacArthur and Olive Turner in 1930. He later moved to Marlboro, Vermont, as his father moved from the University of Toronto to Marlboro College. MacArthur received his Bachelor's degree in mathematics from Marlboro College, followed by a Master's degree in mathematics from Brown University in 1953. A student of G. Evelyn Hutchinson, MacArthur earned his Ph.D. from Yale University in 1957; his thesis was on the division of ecological niches among five warbler species in the conifer forests of Maine and Vermont. From 1957 to 1958, MacArthur worked as a postdoc with David Lack. Career MacArthur was a professor at the University of Pennsylvania, 1958–65, and professor of biology at Princeton University, 1965-72. He played a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metapopulation
A metapopulation consists of a group of spatially separated populations of the same species which interact at some level. The term metapopulation was coined by Richard Levins in 1969 to describe a model of population dynamics of insect pests in agricultural fields, but the idea has been most broadly applied to species in naturally or artificially fragmented habitats. In Levins' own words, it consists of "a population of populations". A metapopulation is generally considered to consist of several distinct populations together with areas of suitable habitat which are currently unoccupied. In classical metapopulation theory, each population cycles in relative independence of the other populations and eventually goes extinct as a consequence of demographic stochasticity (fluctuations in population size due to random demographic events); the smaller the population, the more chances of inbreeding depression and prone to extinction. Although individual populations have finite life-s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stochastic
Stochastic (, ) refers to the property of being well described by a random probability distribution. Although stochasticity and randomness are distinct in that the former refers to a modeling approach and the latter refers to phenomena themselves, these two terms are often used synonymously. Furthermore, in probability theory, the formal concept of a '' stochastic process'' is also referred to as a ''random process''. Stochasticity is used in many different fields, including the natural sciences such as biology, chemistry, ecology, neuroscience, and physics, as well as technology and engineering fields such as image processing, signal processing, information theory, computer science, cryptography, and telecommunications. It is also used in finance, due to seemingly random changes in financial markets as well as in medicine, linguistics, music, media, colour theory, botany, manufacturing, and geomorphology. Etymology The word ''stochastic'' in English was originally used as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Demographic
Demography () is the statistical study of populations, especially human beings. Demographic analysis examines and measures the dimensions and dynamics of populations; it can cover whole societies or groups defined by criteria such as education, nationality, religion, and ethnicity. Educational institutions usually treat demography as a field of sociology, though there are a number of independent demography departments. These methods have primarily been developed to study human populations, but are extended to a variety of areas where researchers want to know how populations of social actors can change across time through processes of birth, death, and migration. In the context of human biological populations, demographic analysis uses administrative records to develop an independent estimate of the population. Demographic analysis estimates are often considered a reliable standard for judging the accuracy of the census information gathered at any time. In the labor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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