scholarly journals ONCE AGAIN ABOUT THE BIOTIC COMMUNITY

ÈKOBIOTEH ◽  
2020 ◽  
Vol 3 (3) ◽  
pp. 472-477
Author(s):  
G.S. Rozenberg ◽  
Keyword(s):  
Population Genetics ◽  
Community Ecology ◽  
Neutral Theory ◽  
Patch Dynamics ◽  
Species Structure ◽  
Biotic Community ◽  
Temporal Aspect

Community ecology studies the patterns of changes in biodiversity, species structure, and the number of individual populations in a spatial and temporal aspect. The article discusses some modern theories of community ecology (neutral theory, patch dynamics, M. Vellend's ideas about four basic processes in communities similar to processes of population genetics [selection, drift, dispersal, selection], etc.).

Metacommunities

2019 ◽  
pp. 266-284
Author(s):  
Gary G. Mittelbach ◽  
Brian J. McGill
Keyword(s):  
Species Diversity ◽  
Species Interactions ◽  
Neutral Theory ◽  
Patch Dynamics ◽  
Species Traits ◽  
Local Communities ◽  
The Other ◽  
Species Sorting ◽  
Niche Differences ◽  
Dynamics Of Populations

Just as the dispersal of individuals may link the dynamics of populations in space, the dispersal of species among communities may link local communities into a metacommunity. Four different perspectives characterize how dispersal rates, environmental heterogeneity, and species traits interact to influence diversity in metacommunities. These perspectives are: patch dynamics, species sorting, mass effects, and the neutral perspective. The neutral perspective stands in stark contrast to the other three perspectives in that it assumes that niche differences between species are unimportant and that species are demographically identical in terms of their birth, death, and dispersal rates. Under the neutral perspective, species diversity is maintained by a balance between speciation, extinction, and dispersal. Although neutral theory is incompatible with realistic modes and rates of speciation, it has been enormously influential in focusing our attention on the linkages between species interactions on local scales, and evolutionary and biogeographic processes occurring on large scales.

Motoo Kimura. 13 November 1924—13 November 1994

1997 ◽  
Vol 43 ◽  
pp. 255-265 ◽  
Author(s):  
James F. Crow
Keyword(s):  
Population Genetics ◽  
Natural Selection ◽  
Neutral Theory ◽  
Random Chance ◽  
Evolutionary Changes ◽  
Sewall Wright ◽  
Theoretical Population ◽  
Theoretical Population Genetics

Motoo Kimura's research contributions can be divided into two parts. The first is a series of papers on theoretical population genetics, the quality and quantity of which place him as the successor to the great trinity, R.A. Fisher, J.B.S. Haldane and Sewall Wright. The second is his neutral theory, the idea that the bulk of molecular evolutionary changes are driven by mutation and random chance, rather than by natural selection. The neutral theory brought him fame far beyond the confines of population genetics, and has made the name Motoo Kimura well-known to evolutionary biologists. (Motoo is pronounced ‘Mo-toe’, not ‘Mo-two’. By repeating the letter O, Kimura sought to indicate that this syllable was to be protracted. Unfortunately, rather than producing the desired effect, this more often led to mispronunciation.)

scholarly journals Is Aldo Leopold’s “Land Community” an Individual?

2018 ◽  
Author(s):  
Roberta L. Millstein
Keyword(s):  
Community Ecology ◽  
Moral Obligation ◽  
Ecological Theory ◽  
Theory And Practice ◽  
Land Ethic ◽  
Biotic Community ◽  
Community Or ◽  
Community Concept ◽  
Land Community

The concept of “land community” (or “biotic community”) that features centrally in Aldo Leopold’s Land Ethic has typically been equated with the concept of “ecosystem.” The author argues that we need to rethink Leopold’s concept of land community. First, Leopold’s views are not identical to those of his contemporaries, although they resemble those of some subsequent ecologists. Second, the land community concept does not map cleanly onto the concept of “ecosystem”; it also incorporates elements of the “community” concept in community ecology. Third, the question of whether land communities have boundaries can be addressed by an analysis of land communities as individuals. There are challenges to be worked out, but the author argues that these challenges can be resolved. The result is a defensible land community concept that is ontologically robust enough to be a locus of moral obligation while being consistent with contemporary ecological theory and practice.

Species coexistence

2020 ◽  
pp. 5-27 ◽  
Author(s):  
Peter Chesson
Keyword(s):  
Community Ecology ◽  
Species Coexistence ◽  
Neutral Theory ◽  
Niche Overlap ◽  
Shared Environment ◽  
Similar Species ◽  
Average Performance ◽  
Niche Differences ◽  
Ecological Drift ◽  
Average Fitness

In most places on Earth, many similar species are found coexisting. This key observation is often explained in terms of ecological differences in how species interact with their shared environment, that is, in terms of their niche differences. Niche differences can to lead to stable coexistence in contrast to the ecological drift predicted by the neutral theory of community ecology. Coexistence becomes stabilized as density feedback within species is strengthened relative to density feedback between species. Coexistence is reflective of two distinct niche comparisons, niche overlap, and species relative average fitness. In general, low niche overlap (dissimilarity in use of the environment) and similar average fitnesses (similar average performance) favor coexistence. For a unified theory of species coexistence, it is shown how the Lotka–Volterra competition model can reflect and quantify several types of niche comparison, including comparisons of resource use, susceptibility to natural enemies, and temporal variation in activity.

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