Natural and Null Food Webs: A Critical Investigation of Biological and Methodological Explanations for Food Web Structure

9905446Martinez 食物网理论正在经历从食物网中尺度不变模式到恒定连接和尺度依赖模式的范式转变。这笔博士后启动资金将通过严格、系统地将经验观察到的食物网模式与零模型和机械模型生成的模式进行比较，阐明目前尚未确定的这种转变的生物学意义。正如丰富的生态学历史所表明的那样，这种比较对于评估以下主张至关重要：稳健的食物网模式表明了限制生态系统结构和功能的强大生物过程。由于缺乏比较，食物网模式是方法论人工产物的假设需要在对模式的生物学基础进行大量研究之前进行系统研究。先前对自然食物网和无效食物网进行比较的工作相对较少，表明生物过程是造成广泛的陆地、水生和海洋生态系统中连接价值相对较低的原因。为了描述造成这种和其他食物网模式的过程，候选生物机制将被形式化为构建食物网的计算机模型。以这种方式构建的食物网将与凭经验观察到的食物网进行比较。这种比较将表明模拟机制是否值得进一步分析和实验研究作为食物网模式的潜在来源。

9905446MartinezFood-web theory is undergoing a paradigmatic shift from scale-invariant patterns in food webs to constant connectance and scale-dependent patterns. This postdoctoral starter grant will clarify the currently undetermined biological significance of the shift by rigorously and systematically comparing empirically observed food web patterns with patterns generated by null and mechanistic models. As a rich history in ecology has shown, such comparisons are critical to evaluating the claim that robust food web patterns are indicative of powerful biological processes that constrain the structure and function of ecological systems. Lacking the comparisons, the hypothesis that food web patterns are methodological artifacts needs to be systematically studied before much work on the biological basis for the patterns is warranted. The relatively small amount of previous work comparing natural and null food webs suggests that biological processes are responsible for the relatively low value of connectance in a wide range of terrestrial, aquatic and marine ecological systems. In an attempt to delineate the processes responsible for this and other food web patterns, candidate biological mechanisms will be formalized into computer models that construct food webs. Webs constructed in this manner will be compared against empirically observed food webs. This comparison will indicate whether the simulated mechanisms deserve further analytical and experimental investigation as potential sources of food web patterns.