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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] |
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] |
Biological Dispersal
Biological dispersal refers to both the movement of individuals (animals, plants, fungi, bacteria, etc.) from their birth site to their breeding site ('natal dispersal'), as well as the movement from one breeding site to another ('breeding dispersal'). Dispersal is also used to describe the movement of propagules such as seeds and spores. Technically, dispersal is defined as any movement that has the potential to lead to gene flow. The act of dispersal involves three phases: departure, transfer, settlement and there are different fitness costs and benefits associated with each of these phases. Through simply moving from one habitat patch to another, the dispersal of an individual has consequences not only for individual fitness, but also for population dynamics, population genetics, and species distribution. Understanding dispersal and the consequences both for evolutionary strategies at a species level, and for processes at an ecosystem level, requires understanding on th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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'') level. Biodiversity is not distributed evenly on Earth; it is usually greater in the tropics as a result of the warm climate and high primary productivity in the region near the equator. Tropical forest ecosystems cover less than 10% of earth's surface and contain about 90% of the world's species. Marine biodiversity is usually higher along coasts in the Western Pacific, where sea surface temperature is highest, and in the mid-latitudinal band in all oceans. There are latitudinal gradients in species diversity. Biodiversity generally tends to cluster in hotspots, and has been increasing through time, but will be likely to slow in the future as a primary result of deforestation. It encompasses the evolutionary, ecological, and cultural ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conservation Biology
Conservation biology is the study of the conservation of nature and of Earth's biodiversity with the aim of protecting species, their habitats, and ecosystems from excessive rates of extinction and the erosion of biotic interactions. It is an interdisciplinary subject drawing on natural and social sciences, and the practice of natural resource management. The conservation ethic is based on the findings of conservation biology. Origins The term conservation biology and its conception as a new field originated with the convening of "The First International Conference on Research in Conservation Biology" held at the University of California, San Diego in La Jolla, California, in 1978 led by American biologists Bruce A. Wilcox and Michael E. Soulé with a group of leading university and zoo researchers and conservationists including Kurt Benirschke, Sir Otto Frankel, Thomas Lovejoy, and Jared Diamond. The meeting was prompted due to concern over tropical deforestation, disappearin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Overharvesting
Overexploitation, also called overharvesting, refers to harvesting a renewable resource to the point of diminishing returns. Continued overexploitation can lead to the destruction of the resource, as it will be unable to replenish. The term applies to natural resources such as Aquifer, water aquifers, Pasture, grazing pastures and forests, wild medicinal plants, fish stocks and other wildlife. In ecology, overexploitation describes one of the five main activities threatening global biodiversity. Ecologists use the term to describe populations that are harvested at an unsustainable rate, given their natural rates of mortality and capacities for reproduction. This can result in extinction at the population level and even extinction of whole species. In conservation biology, the term is usually used in the context of human economic activity that involves the taking of biological resources, or organisms, in larger numbers than their populations can withstand. The term is also used ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Commercial Fisheries
Commercial fishing is the activity of catching fish and other seafood for commercial profit, mostly from wild fisheries. It provides a large quantity of food to many countries around the world, but those who practice it as an industry must often pursue fish far into the ocean under adverse conditions. Large-scale commercial fishing is also known as industrial fishing. The major fishing industries are not only owned by major corporations but by small families as well. In order to adapt to declining fish populations and increased demand, many commercial fishing operations have reduced the sustainability of their harvest by fishing further down the food chain. This raises concern for fishery managers and researchers, who highlight how further they say that for those reasons, the sustainability of the marine ecosystems could be in danger of collapsing. Commercial fishermen harvest a wide variety of animals. However, a very small number of species support the majority of the world' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IUCN Red List
The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is the world's most comprehensive inventory of the global conservation status of biological species. It uses a set of precise criteria to evaluate the extinction risk of thousands of species and subspecies. These criteria are relevant to all species and all regions of the world. With its strong scientific base, the IUCN Red List is recognized as the most authoritative guide to the status of biological diversity. A series of Regional Red Lists are produced by countries or organizations, which assess the risk of extinction to species within a political management unit. The aim of the IUCN Red List is to convey the urgency of conservation issues to the public and policy makers, as well as help the international community to reduce species extinction. According to IUCN the formally stated goals of the Red List are to provi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Holt 3
Holt or holte may refer to: Natural world *Holt (den), an otter den * Holt, an area of woodland Places Australia * Holt, Australian Capital Territory * Division of Holt, an electoral district in the Australian House of Representatives in Victoria Canada *Holt, Ontario, a hamlet Denmark *Holte, a town in Rudersdal municipality, Copenhagen county Germany * Holt, Germany, a municipality in Schleswig-Holstein Iceland *Holt (Akureyri), a residence in Sandgerðisbót Akureyri *Skálholt, the first bishopric of medieval Iceland and the site of a cathedral The Netherlands * Holt, Overijssel, a town in Overijssel Norway * Holt, Aust-Agder, a former municipality in Aust-Agder county, Norway (now a part of Tvedestrand municipality) Romania * Holt, a village in Letea Veche Commune, Bacău County United Kingdom *Holt, Dorset ** Holt Heath, Dorset *Holt End, Hampshire *Holt Town, Manchester *Holt, Norfolk **Holt (North Norfolk Railway) railway station **Holt railway station, a clos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Holt 2
Holt or holte may refer to: Natural world *Holt (den), an otter den * Holt, an area of woodland Places Australia * Holt, Australian Capital Territory * Division of Holt, an electoral district in the Australian House of Representatives in Victoria Canada *Holt, Ontario, a hamlet Denmark *Holte, a town in Rudersdal municipality, Copenhagen county Germany * Holt, Germany, a municipality in Schleswig-Holstein Iceland *Holt (Akureyri), a residence in Sandgerðisbót Akureyri *Skálholt, the first bishopric of medieval Iceland and the site of a cathedral The Netherlands * Holt, Overijssel, a town in Overijssel Norway * Holt, Aust-Agder, a former municipality in Aust-Agder county, Norway (now a part of Tvedestrand municipality) Romania * Holt, a village in Letea Veche Commune, Bacău County United Kingdom *Holt, Dorset ** Holt Heath, Dorset *Holt End, Hampshire *Holt Town, Manchester *Holt, Norfolk **Holt (North Norfolk Railway) railway station **Holt railway station, a clos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Population Dynamics
Population dynamics is the type of mathematics used to model and study the size and age composition of populations as dynamical systems. History Population dynamics has traditionally been the dominant branch of mathematical biology, which has a history of more than 220 years,Malthus, Thomas Robert. An Essay on the Principle of Population: Library of Economics although over the last century the scope of mathematical biology has greatly expanded. The beginning of population dynamics is widely regarded as the work of Malthus, formulated as the Malthusian growth model. According to Malthus, assuming that the conditions (the environment) remain constant ('' ceteris paribus''), a population will grow (or decline) exponentially. This principle provided the basis for the subsequent predictive theories, such as the demographic studies such as the work of Benjamin Gompertz and Pierre François Verhulst in the early 19th century, who refined and adjusted the Malthusian demographic model. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Holt 1
Holt or holte may refer to: Natural world *Holt (den), an otter den * Holt, an area of woodland Places Australia * Holt, Australian Capital Territory * Division of Holt, an electoral district in the Australian House of Representatives in Victoria Canada *Holt, Ontario, a hamlet Denmark *Holte, a town in Rudersdal municipality, Copenhagen county Germany * Holt, Germany, a municipality in Schleswig-Holstein Iceland *Holt (Akureyri), a residence in Sandgerðisbót Akureyri *Skálholt, the first bishopric of medieval Iceland and the site of a cathedral The Netherlands * Holt, Overijssel, a town in Overijssel Norway * Holt, Aust-Agder, a former municipality in Aust-Agder county, Norway (now a part of Tvedestrand municipality) Romania * Holt, a village in Letea Veche Commune, Bacău County United Kingdom *Holt, Dorset ** Holt Heath, Dorset *Holt End, Hampshire *Holt Town, Manchester *Holt, Norfolk **Holt (North Norfolk Railway) railway station **Holt railway station, a clos ... [...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-spa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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