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Abundance (ecology)
In ecology, local abundance is the relative representation of a species in a particular ecosystem. It is usually measured as the number of individuals found per sample. The ratio of abundance of one species to one or multiple other species living in an ecosystem is referred to as relative species abundances. Both indicators are relevant for computing biodiversity. A variety of sampling methods are used to measure abundance. For larger animals, these may include spotlight counts, track counts and roadkill counts, as well as presence at monitoring stations. In many plant communities the abundances of plant species are measured by plant cover, i.e. the relative area covered by different plant species in a small plot. Abundance is in simplest terms usually measured by identifying and counting every individual of every species in a given sector. It is common for the distribution of species to be skewed so that a few species take up the bulk of individuals collected. Relative species ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Effect Of Herbivore Abundance In Seagrass Meadows
Effect may refer to: * A result or change of something ** List of effects ** Cause and effect, an idiom describing causality Pharmacy and pharmacology * Drug effect, a change resulting from the administration of a drug ** Therapeutic effect, a beneficial change in medical condition, often caused by a drug ** Adverse effect or side effect, an unwanted change in medical condition caused by a drug In media * Special effect, an artificial illusion ** Sound effect, an artificially created or enhanced sound ** Visual effects, artificially created or enhanced images *Audio signal processing ** Effects unit, a device used to manipulate electronic sound *** Effects pedal, a small device attached to an instrument to modify its sound Other uses * Effects, one's personal property or belongings * Effects (G.I. Joe), a fictional character in the G.I. Joe universe * ''Effects'' (film), a 2005 film * Effect size, a measure of the strength of a relationship between two variables * Effect syst ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Regional Distribution
In geography, regions, otherwise referred to as zones, lands or territories, are areas that are broadly divided by physical characteristics (physical geography), human impact characteristics (human geography), and the interaction of humanity and the environment ( environmental geography). Geographic regions and sub-regions are mostly described by their imprecisely defined, and sometimes transitory boundaries, except in human geography, where jurisdiction areas such as national borders are defined in law. Apart from the global continental regions, there are also hydrospheric and atmospheric regions that cover the oceans, and discrete climates above the land and water masses of the planet. The land and water global regions are divided into subregions geographically bounded by large geological features that influence large-scale ecologies, such as plains and features. As a way of describing spatial areas, the concept of regions is important and widely used among the many branches o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Species Richness
Species richness is the number of different species represented in an ecological community, landscape or region. Species richness is simply a count of species, and it does not take into account the abundances of the species or their 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 selected in different ways. They can be, for example, trees found in an 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 of the organisms of interest is well enough known. Applying different species delimitations will lead to different species richness values ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Range (biology)
Species distribution —or species dispersion — is the manner in which a biological taxon is spatially arranged. The geographic limits of a particular taxon's distribution is its range, often represented as shaded areas on a map. Patterns of distribution change depending on the scale at which they are viewed, from the arrangement of individuals within a small family unit, to patterns within a population, or the distribution of the entire species as a whole (range). Species distribution is not to be confused with dispersal, which is the movement of individuals away from their region of origin or from a population center of high density. Range In biology, the range of a species is the geographical area within which that species can be found. Within that range, distribution is the general structure of the species population, while dispersion is the variation in its population density. Range is often described with the following qualities: * Sometimes a distinction is made betw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plant Cover
The abundances of plant species are often measured by plant cover, which is the relative area covered by different plant species in a small plot. Plant cover is not biased by the size and distributions of individuals, and is an important and often measured characteristic of the composition of plant communities. Usage Plant cover data may be used to classify the studied plant community into a vegetation type, to test different ecological hypothesis on plant abundance, and in gradient studies, where the effects of different environmental gradients on the abundance of specific plant species are studied . Measurement The most common way to measure plant cover in herbal plant communities, is to make a visual assessment of the relative area covered by the different species in a small plot (see quadrat). The visually assessed cover of a plant species is then recorded as a continuous variable between 0 and 1, or divided into interval classes as an ordinal variable. An alternative methodo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Occupancy–abundance Relationship
In ecology, the occupancy–abundance (O–A) relationship is the relationship between the abundance of species and the size of their ranges within a region. This relationship is perhaps one of the most well-documented relationships in macroecology, and applies both intra- and interspecifically (within and among species). In most cases, the O–A relationship is a positive relationship.Gaston, K.J. 1996. The multiple forms of the interspecific abundance-distribution relationship. Oikos 75:211 – 220. Although an O–A relationship would be expected, given that a species colonizing a region must pass through the origin (zero abundance, zero occupancy) and could reach some theoretical maximum abundance and distribution (that is, occupancy and abundance can be expected to co-vary), the relationship described here is somewhat more substantial, in that observed changes in range are associated with greater-than-proportional changes in abundance. Although this relationship appears to be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cover-abundance
Cover-abundance is a measure of plant cover, used in phytosociology (or vegetation science). It is based on percentages at the top end, but uses abundance estimates for species with a low plant cover. Several scales of cover-abundance are used, e.g. the original 5-point cover scale of Braun-Blanquet or the Domin Karel Domin (4 May 1882, Kutná Hora, Kingdom of Bohemia – 10 June 1953, Prague) was a Czech botanist and politician. After gymnasium school studies in Příbram, he studied botany at the Charles University in Prague, and graduated in 1906 ... scale, with finer subdivisions (from simple presence through 10 grades of linked cover-abundance). External links Definition of cover-abundance at encyclopedia.com Ecology Ecology terminology Ecological metrics ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Abundance Estimation
Abundance estimation comprises all statistical methods for estimating the number of individuals in a population. In ecology, this may be anything from estimating the number of daisies in a field to estimating the number of blue whale The blue whale (''Balaenoptera musculus'') is a marine mammal and a baleen whale. Reaching a maximum confirmed length of and weighing up to , it is the largest animal known to have ever existed. The blue whale's long and slender body can ...s in the ocean. Plot sampling Mark-recapture Distance sampling References Further reading Distance Sampling: Estimating Abundance of Biological Populations – S. T. Buckland, D. R. Anderson, K. P. Burnham, J. L. LaakeEstimating Abundance of African Wildlife: An Aid to Adaptive Management – Hugo JachmannAdvanced Distance Sampling: Estimating Abundance of Biological PopulationsGeostatistics for Estimating Fish Abundance – J. Rivoirard, J. Simmonds, K. G. Foote, P. Fernandes, N. BezEstim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Relative Abundance Distribution
In the field of ecology, the relative abundance distribution (RAD) or species abundance distribution describes the relationship between the number of species observed in a field study as a function of their observed abundance. The graphs obtained in this manner are typically fitted to a Zipf–Mandelbrot law, the exponent of which serves as an index of biodiversity Biodiversity or biological diversity is the variety and variability of life on Earth. Biodiversity is a measure of variation at the genetic (''genetic variability''), species (''species diversity''), and ecosystem (''ecosystem diversity'') l ... in the ecosystem under study. Notes and references Ecological metrics {{ecology-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Generalist And Specialist Species
A generalist species is able to thrive in a wide variety of environmental conditions and can make use of a variety of different resources (for example, a heterotroph with a varied diet). A specialist species can thrive only in a narrow range of environmental conditions or has a limited diet. Most organisms do not all fit neatly into either group, however. Some species are highly specialized (the most extreme case being monophagous, eating one specific type of food), others less so, and some can tolerate many different environments. In other words, there is a continuum from highly specialized to broadly generalist species. Description Omnivores are usually generalists. Herbivores are often specialists, but those that eat a variety of plants may be considered generalists. A well-known example of a specialist animal is the monophagous koala, which subsists almost entirely on eucalyptus leaves. The raccoon is a generalist, because it has a natural range that includes most of North ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ecology
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 managemen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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