期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2015
卷号：112
期号：6
页码：1791-1796
DOI：10.1073/pnas.1422475112
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：SignificancePower laws of scaling are major achievements of ecology. Such empirical laws say that one quantity varies as some power of another quantity. For example, Taylor's law says that the variance of population density changes as a power of the mean population density. Density-mass allometry says that the mean population density is a power-law function of the mean body mass. We show, to our knowledge for the first time in any animal community, that the variance of population density is a power-law function of mean body mass, and that the parameters of all three power laws just mentioned are influenced by whether the animals are parasites, free-living parasitized species, or free-living unparasitized species. Lifestyle matters in ecology. How do the lifestyles (free-living unparasitized, free-living parasitized, and parasitic) of animal species affect major ecological power-law relationships? We investigated this question in metazoan communities in lakes of Otago, New Zealand. In 13,752 samples comprising 1,037,058 organisms, we found that species of different lifestyles differed in taxonomic distribution and body mass and were well described by three power laws: a spatial Taylor's law (the spatial variance in population density was a power-law function of the spatial mean population density); density-mass allometry (the spatial mean population density was a power-law function of mean body mass); and variance-mass allometry (the spatial variance in population density was a power-law function of mean body mass). To our knowledge, this constitutes the first empirical confirmation of variance-mass allometry for any animal community. We found that the parameter values of all three relationships differed for species with different lifestyles in the same communities. Taylor's law and density-mass allometry accurately predicted the form and parameter values of variance-mass allometry. We conclude that species of different lifestyles in these metazoan communities obeyed the same major ecological power-law relationships but did so with parameters specific to each lifestyle, probably reflecting differences among lifestyles in population dynamics and spatial distribution.
关键词：parasite ; metazoan ; power law ; Taylor’s law ; allometry
