Geometry, heterogeneity and competition in variable environments
Geometry, heterogeneity and competition in variable environments
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可变环境中的几何、异质性和竞争
DOI：
10.1098/rstb.1990.0190
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发表时间：
1990
期刊：
影响因子：
--
通讯作者：
P. Chesson
中科院分区：
文献类型：
--
作者：
P. Chesson
环境波动对竞争物种共存的影响可以通过一种新的几何分析来理解。这一分析表明，当环境波动时，低密度的物种如何获得平均增长率优势，并且所有物种的增长率都具有称为亚加性的特殊几何形式。这种低密度优势反对竞争性排斥。加性增长率不提供这种低密度优势，而超加性增长率促进了竞争排斥。增长率几何可以用种群内的异质性来理解。总的种群增长被分成不同的组成部分，如可能由不同的生活史阶段、表型或不同微生境中的亚群贡献。这种种群内异质性的相关方面可以表现为人口增长的不同组成部分对环境和竞争因素的敏感度的散点图，并可以作为协方差定量衡量。三因素模型有助于在概念上将人口增长划分为适当的组成部分。
The effects of environmental fluctuations on coexistence of competing species can be understood by a new geometric analysis. This analysis shows how a species at low density gains an average growth rate advantage when the environment fluctuates and all species have growth rates of the particular geometric form called subadditive. This low density advantage opposes competitive exclusion. Additive growth rates confer no such low density advantage, while superadditive growth rates promote competitive exclusion. Growth-rate geometry can be understood in terms of heterogeneity within populations. Total population growth is divided into different components, such as may be contributed by different life-history stages, phenotypes, or subpopulations in different microhabitats. The relevant aspects of such within-population heterogeneity can be displayed as a scatter plot of sensitivities of different components of population growth to environmental and competitive factors, and can be measured quantitatively as a covariance. A three-factor model aids the conceptual division of population growth into suitable components.