Collaborative Research: Moths, Ants, and Carnivorous Plants: the Spatial Dimension of Species Interactions

生态学家早就认识到，相互作用的物种的共存取决于不同但相互关联的栖息地的多样性。大多数物种共存模型都将这些栖息地“斑块”视为不变的景观元素，但在现实中，它们的大小和形状都在不断变化。生活在它们身上的食物网的结构和动态既控制着这些变化，也依赖于这些变化。哈佛大学和佛蒙特州大学的这项合作项目试图了解物种相互作用如何改变整个景观中动态生境斑块的空间分布，并确定这些斑块内和这些斑块之间食物网的结构。这个为期五年的研究项目的实验系统是Sarracenia“微生态系统”：北部猪笼草植物Sarracenia Purpurea；生活在其充满雨水的叶子中的细菌、原生动物、轮虫、螨虫和苍蝇幼虫组成的独特食物网；三种沼泽栖息地蚂蚁，它们是这种肉食植物的主要猎物；以及猪笼草蛾Exyra fax的幼虫，它们切割和排干猪笼草，并移走食物网栖息地。对新英格兰50个沼泽的调查和在哈佛森林长期生态研究地点进行的三次田间试验的结果将使模拟模型参数化，以预测蚂蚁、蛾和植物种群的空间结构变化，以及与植物相关的水生食物网的结构和组成。这项研究项目有三个广泛的影响。首先，这项研究吸引了本科生、研究生、K-12教师、研究助理和一名博士后参与合作研究。其次，这项研究将产生一个普遍适用的框架，用于理解复杂的生物体组合如何在空间结构变化的环境中组装、拆卸和重新组装。第三，将扩大使用一个模型生态系统--Sarracenia微生态系统--以涵盖食物网的景观级动态。

Ecologists have long recognized that coexistence of interacting species depends on a diversity of separate, but linked habitats. Most models of species coexistence treat these habitat "patches" as unchanging elements of the landscape, but in reality, they are constantly changing in size and shape. The structure and dynamics of the food webs that inhabit them both control and depend on these changes. This collaborative project between investigators at Harvard University and the University of Vermont seeks to understand how species interactions change the spatial distribution of dynamic habitat patches across the landscape, and to determine how food webs are structured within and among these patches. The experimental system for this five-year research project is the Sarracenia "microecosystem": the northern pitcher-plant Sarracenia purpurea; the unique food web of bacteria, protozoa, rotifers, mites, and fly larvae that live within its rainwater-filled leaves; three species of bog-inhabiting ants that are the primary prey for this carnivorous plant; and larvae of the pitcher-plant moth, Exyra fax, which cut and drain pitchers and remove food web habitat. Results from surveys of 50 New England bogs and three field experiments conducted at the Harvard Forest Long-Term Ecological Research site will parameterize a simulation model to predict changes in spatial structure of ant, moth, and plant populations, and the structure and composition of the aquatic food web associated with the plant. There are three broad impacts to this research project. First, the research engages undergraduates, graduate students, K-12 teachers, research assistants, and a post-doc in collaborative research. Second, this research will yield a generally applicable framework for understanding how complex assemblages of organisms assemble, disassemble, and reassemble in spatially-structured changing environments. Third, the use of a model ecological system - the Sarracenia microecosystem - will be expanded to encompass landscape-level dynamics of food webs.