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Relative species abundance is a component of biodiversity and is a measure of how common or rare a species is relative to other species in a defined location or community. [1]
A variety of objective means exist to empirically measure biodiversity. Each measure relates to a particular use of the data, and is likely to be associated with the variety of genes. Biodiversity is commonly measured in terms of taxonomic richness of a geographic area over a time interval. In order to calculate biodiversity, species evenness ...
In contrast to these "mechanistic" explanations, others assert the need to test whether the pattern is simply the result of a random sampling process. [7] Species–area relationships are often evaluated in conservation science in order to predict extinction rates in the case of habitat loss and habitat fragmentation. [8]
Species richness, or biodiversity, increases from the poles to the tropics for a wide variety of terrestrial and marine organisms, often referred to as the latitudinal diversity gradient. [1] The latitudinal diversity gradient is one of the most widely recognized patterns in ecology. [1] It has been observed to varying degrees in Earth's past. [2]
Statistical tests (such as t-test, chi squared, etc.) can then be used to determine whether R is significantly different from 1. The variance/mean ratio method focuses mainly on determining whether a species fits a randomly spaced distribution, but can also be used as evidence for either an even or clumped distribution. [ 22 ]
Hubbell built on earlier neutral models, including Robert MacArthur and E.O. Wilson's theory of island biogeography [1] and Stephen Jay Gould's concepts of symmetry and null models. [7] An "ecological community" is a group of trophically similar, sympatric species that actually or potentially compete in a local area for the same or similar ...
Empirical measurements are generally restricted to a specific habitat, such as a cave or a pond, and principles gleaned from small-scale studies are extrapolated to larger systems. [72] Feeding relations require extensive investigations, e.g. into the gut contents of organisms, which can be difficult to decipher, or stable isotopes can be used ...
Pattern is the term for the contents and internal order of a heterogeneous area of land. [17] A landscape with structure and pattern implies that it has spatial heterogeneity, or the uneven distribution of objects across the landscape. [6] Heterogeneity is a key element of landscape ecology that separates this discipline from other branches of ...