Effects of spatial scale of sampling on food web structure
Effects of spatial scale of sampling on food web structure
复制标题
采样空间尺度对食物网结构的影响
作者：
S. Wood;R. Russell;Dieta Hanson;Richard J. Williams;J. Dunne
本研究问是否采样的空间尺度改变食物网的结构特性，是否有任何差异是由于物种丰富度和连接性与规模的变化。了解采样努力的不同方面如何影响生态网络结构，对于基础生态学知识和网络分析在保护和管理中的应用都很重要。使用一个高分辨率的食物网的海洋潮间带生态系统的Sanak群岛在东部阿留申群岛，阿拉斯加州，我们评估如何共同研究的网络结构的属性不同的食物网采样在五个层次的空间尺度代表六个数量级的面积分布在整个群岛的281个版本。物种（S）和链接（L）丰富度都增加了约一个数量级，在五个空间尺度。每个物种的链接（L/S）增加了一倍多，而连接度（C）下降了约三分之二。网络结构的14个常用性质随空间尺度的变化呈现出系统性的变化，有的增加，有的减少。虽然生态网络的性质随采样范围而系统地变化，但使用生态位模型和幂律标度关系的分析表明，对于许多属性，这种明显的敏感性是由于随着空间尺度的增加，网络的S增加，C减少。只要考虑到S和C的影响，区域抽样偏差对我们理解网络结构的许多方面没有特别的影响。然而，确实需要注意一些属性，如循环中的物种比例，随着采样空间尺度的增加，其增加幅度超过预期。
This study asks whether the spatial scale of sampling alters structural properties of food webs and whether any differences are attributable to changes in species richness and connectance with scale. Understanding how different aspects of sampling effort affect ecological network structure is important for both fundamental ecological knowledge and the application of network analysis in conservation and management. Using a highly resolved food web for the marine intertidal ecosystem of the Sanak Archipelago in the Eastern Aleutian Islands, Alaska, we assess how commonly studied properties of network structure differ for 281 versions of the food web sampled at five levels of spatial scale representing six orders of magnitude in area spread across the archipelago. Species (S) and link (L) richness both increased by approximately one order of magnitude across the five spatial scales. Links per species (L/S) more than doubled, while connectance (C) decreased by approximately two-thirds. Fourteen commonly studied properties of network structure varied systematically with spatial scale of sampling, some increasing and others decreasing. While ecological network properties varied systematically with sampling extent, analyses using the niche model and a power-law scaling relationship indicate that for many properties, this apparent sensitivity is attributable to the increasing S and decreasing C of webs with increasing spatial scale. As long as effects of S and C are accounted for, areal sampling bias does not have a special impact on our understanding of many aspects of network structure. However, attention does need be paid to some properties such as the fraction of species in loops, which increases more than expected with greater spatial scales of sampling.