A Critical Re-Examination of Food Web Patterns in Real Ecosystems

这项拟议研究的中心目的是对真实生态系统中所谓的营养结构经验法则进行批判性的重新评估。在威斯康星大学鲑鱼湖站和威斯康星州自然资源部的研究人员的合作下，将组装第一个专门用于表示大规模生态系统的营养结构的全系统数据库。由于水生环境代表了食物网法律所依据的系统的最大部分，这项工作将集中在小石湖，这是一个长期研究地点，作为正在进行的实验性酸雨监测项目的一部分进行了广泛研究，并承诺产生一套24个高度详细的食物网数据集。一项初步研究证实，在这里可以获得数量惊人的营养信息，并且可以尝试相对较高的分类和时间分辨率。这项研究将包括的细节包括：对所涉及的物种及其取食强度的全面和公平的解决；食物网络结构随季节和个体发育的时间变异性；研究不完整子系统对食物网络格局的影响；以及通过聚合和纳入主要到次要的相互作用系统地改变数据的分辨率而引入的食物网络结构的变化。以下是被问到的一些问题。许多食物网的概括所基于的数据如何代表真实的系统？食品网络属性对数据的时间和分类分辨率的依赖程度如何？像食物链长度这样的属性何时会真正受到环境的限制，或者只是受到数据质量的限制？

The central aim of this proposed research is to provide a critical reappraisal of so-called empirical laws of trophic structure in real ecosystems. In collaboration with researchers at the University of Wisconsin Trout Lake Station, and the Wisconsin Department of Natural Resources, the first whole-system data base designed specifically to represent the trophic structure of a large-scale ecosystem will be assembled. Because aquatic environments represent the largest fraction of systems upon which the food web laws are based, this effort will focus on Little Rock Lake, a long-term study site which has been extensively studied as part of an ongoing experimental acid rain monitoring project, and which promises to yield a suite of 24 highly detailed food web data sets. A pilot study confirmed the availability of a surprisingly large amount of trophic information here and the relatively high degree of taxonomic and temporal resolution that could be attempted. Amount the details that will be included in this study are: a full and more even- handed resolution of the species involved and their feeding intensities; temporal variability in food web structure with season and ontogeny; the effects on food web patterns of studying incomplete subsystems; and the variation in food web structure introduced by systematically changing the resolution of the data through aggregation and the incorporation of major to minor interactions. The following are some of the questions being asked. How representative of real systems ar ethe data upon which many food web generalizations are based? How dependent are food web properties on the temporal and taxonomic resolution of the data? When is a property such as food chain length truly limited by the environment or simply by the quality of the data?