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Spatial Ecology
Spatial ecology studies the ultimate distributional or spatial unit occupied by a species. In a particular habitat shared by several species, each of the species is usually confined to its own microhabitat or spatial niche because two species in the same general territory cannot usually occupy the same ecological niche for any significant length of time. Overview In nature, organisms are neither distributed uniformly nor at random, forming instead some sort of spatial pattern. This is due to various energy inputs, disturbances, and species interactions that result in spatially patchy structures or gradients. This spatial variance in the environment creates diversity in communities of organisms, as well as in the variety of the observed biological and ecological events. The type of spatial arrangement present may suggest certain interactions within and between species, such as competition, predation, and reproduction. On the other hand, certain spatial patterns may also rule ou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. Other ways of defining species include their karyotype, DNA sequence, morphology, behaviour or ecological niche. In addition, paleontologists use the concept of the chronospecies since fossil reproduction cannot be examined. The most recent rigorous estimate for the total number of species of eukaryotes is between 8 and 8.7 million. However, only about 14% of these had been described by 2011. All species (except viruses) are given a two-part name, a "binomial". The first part of a binomial is the genus to which the species belongs. The second part is called the specific name or the specific epithet (in botanical nomenclature, also sometimes i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Demography
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 lab ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Forage
Forage is a plant material (mainly plant leaves and stems) eaten by grazing livestock. Historically, the term ''forage'' has meant only plants eaten by the animals directly as pasture, crop residue, or immature cereal crops, but it is also used more loosely to include similar plants cut for fodder and carried to the animals, especially as hay or silage. While the term ''forage'' has a broad definition, the term ''forage crop'' is used to define crops, annual or biennial, which are grown to be utilized by grazing or harvesting as a whole crop. Common forages Grasses Grass forages include: *'' Agrostis'' spp. – bentgrasses **''Agrostis capillaris'' – common bentgrass **'' Agrostis stolonifera'' – creeping bentgrass *'' Andropogon hallii'' – sand bluestem *'' Arrhenatherum elatius'' – false oat-grass *'' Bothriochloa bladhii'' – Australian bluestem *'' Bothriochloa pertusa'' – hurricane grass *'' Brachiaria decumbens'' – Surinam grass *'' Brachiaria humidico ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spatial Dependence
Spatial analysis or spatial statistics includes any of the formal techniques which studies entities using their topological, geometric, or geographic properties. Spatial analysis includes a variety of techniques, many still in their early development, using different analytic approaches and applied in fields as diverse as astronomy, with its studies of the placement of galaxies in the cosmos, to chip fabrication engineering, with its use of "place and route" algorithms to build complex wiring structures. In a more restricted sense, spatial analysis is the technique applied to structures at the human scale, most notably in the analysis of geographic data or transcriptomics data. Complex issues arise in spatial analysis, many of which are neither clearly defined nor completely resolved, but form the basis for current research. The most fundamental of these is the problem of defining the spatial location of the entities being studied. Classification of the techniques of spatial ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sexual Reproduction
Sexual reproduction is a type of reproduction that involves a complex life cycle in which a gamete ( haploid reproductive cells, such as a sperm or egg cell) with a single set of chromosomes combines with another gamete to produce a zygote that develops into an organism composed of cells with two sets of chromosomes ( diploid). This is typical in animals, though the number of chromosome sets and how that number changes in sexual reproduction varies, especially among plants, fungi, and other eukaryotes. Sexual reproduction is the most common life cycle in multicellular eukaryotes, such as animals, fungi and plants. Sexual reproduction also occurs in some unicellular eukaryotes. Sexual reproduction does not occur in prokaryotes, unicellular organisms without cell nuclei, such bacteria and archaea. However, some process in bacteria may be considered analogous to sexual reproduction in that they incorporate new genetic information, including bacterial conjugation, transform ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Landscape Ecology
Landscape ecology is the science of studying and improving relationships between ecological processes in the environment and particular ecosystems. This is done within a variety of landscape scales, development spatial patterns, and organizational levels of research and policy. Concisely, landscape ecology can be described as the science of "landscape diversity" as the synergetic result of biodiversity and geodiversity. As a highly interdisciplinary field in systems science, landscape ecology integrates biophysical and analytical approaches with humanistic and holistic perspectives across the natural sciences and social sciences. Landscapes are spatially heterogeneous geographic areas characterized by diverse interacting patches or ecosystems, ranging from relatively natural terrestrial and aquatic systems such as forests, grasslands, and lakes to human-dominated environments including agricultural and urban settings. The most salient characteristics of landscape ecology ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Human Migration
Human migration is the movement of people from one place to another with intentions of settling, permanently or temporarily, at a new location (geographic region). The movement often occurs over long distances and from one country to another (external migration), but internal migration (within a single country) is also possible; indeed, this is the dominant form of human migration globally. Migration is often associated with better human capital at both individual and household level, and with better access to migration networks, facilitating a possible second move. It has a high potential to improve human development, and some studies confirm that migration is the most direct route out of poverty.Age is also important for both work and non-work migration. People may migrate as individuals, in family units or in large groups. There are four major forms of migration: invasion, conquest, colonization and emigration/ immigration. Persons moving from their home due to forced di ... [...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 the t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tobler's First Law Of Geography
The First Law of Geography, according to Waldo Tobler, is "everything is related to everything else, but near things are more related than distant things." This first law is the foundation of the fundamental concepts of spatial dependence and spatial autocorrelation and is utilized specifically for the inverse distance weighting method for spatial interpolation and to support the regionalized variable theory for kriging. The first law of geography is the fundamental assumption used in all spatial analysis. Background Tobler first presented his seminal idea during a meeting of the International Geographical Union's Commission on Qualitative Methods held in 1969 and later published by him in 1970. Tobler was probably not extremely serious when he originally invoked the first law and instead was explaining limitations brought about by computers of the 1970s. He certainly did not think it would be as prominent in geography as it is today. Though simple in its presentation, this id ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Autocorrelation
Autocorrelation, sometimes known as serial correlation in the discrete time case, is the correlation of a signal with a delayed copy of itself as a function of delay. Informally, it is the similarity between observations of a random variable as a function of the time lag between them. The analysis of autocorrelation is a mathematical tool for finding repeating patterns, such as the presence of a periodic signal obscured by noise, or identifying the missing fundamental frequency in a signal implied by its harmonic frequencies. It is often used in signal processing for analyzing functions or series of values, such as time domain signals. Different fields of study define autocorrelation differently, and not all of these definitions are equivalent. In some fields, the term is used interchangeably with autocovariance. Unit root processes, trend-stationary processes, autoregressive processes, and moving average processes are specific forms of processes with autocorrelation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spatial Analysis
Spatial analysis or spatial statistics includes any of the formal techniques which studies entities using their topological, geometric, or geographic properties. Spatial analysis includes a variety of techniques, many still in their early development, using different analytic approaches and applied in fields as diverse as astronomy, with its studies of the placement of galaxies in the cosmos, to chip fabrication engineering, with its use of "place and route" algorithms to build complex wiring structures. In a more restricted sense, spatial analysis is the technique applied to structures at the human scale, most notably in the analysis of geographic data or transcriptomics data. Complex issues arise in spatial analysis, many of which are neither clearly defined nor completely resolved, but form the basis for current research. The most fundamental of these is the problem of defining the spatial location of the entities being studied. Classification of the techniques of spatial ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geostatistics
Geostatistics is a branch of statistics focusing on spatial or spatiotemporal datasets. Developed originally to predict probability distributions of ore grades for mining operations, it is currently applied in diverse disciplines including petroleum geology, hydrogeology, hydrology, meteorology, oceanography, geochemistry, geometallurgy, geography, forestry, environmental control, landscape ecology, soil science, and agriculture (esp. in precision farming). Geostatistics is applied in varied branches of geography, particularly those involving the spread of diseases (epidemiology), the practice of commerce and military planning (logistics), and the development of efficient spatial networks. Geostatistical algorithms are incorporated in many places, including geographic information systems (GIS). Background Geostatistics is intimately related to interpolation methods, but extends far beyond simple interpolation problems. Geostatistical techniques rely on statistical mod ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
