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依赖于不同但又相互联系的栖息地的多样性。大多数物种共存模型将这些栖息地“斑块”视为景观中不变的元素，但实际上，它们的大小和形状都在不断变化。栖息在它们身上的食物网的结构和动态既控制又依赖于这些变化。这个由哈佛大学和佛蒙特大学的研究人员合作的项目旨在了解物种之间的相互作用如何改变景观中动态栖息地斑块的空间分布，并确定这些斑块内部和之间的食物网是如何构建的。这个为期五年的研究项目的实验系统是萨拉色菌“微生态系统”：北方的猪笼草萨拉色菌；独特的食物网，由细菌、原生动物、轮虫、螨虫和苍蝇幼虫组成，它们生活在充满雨水的叶子中；三种居住在沼泽的蚂蚁，它们是这种食肉植物的主要猎物；以及罐草蛾（Exyra fax）的幼虫，它们会切断和排出罐草，并破坏食物网的栖息地。通过对50个新英格兰沼泽的调查和在哈佛森林长期生态研究中心进行的三次实地实验，将参数化一个模拟模型，以预测蚂蚁、飞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。这个研究项目有三个广泛的影响。首先，这项研究让本科生、研究生、K-12教师、研究助理和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组合如何在空间结构不断变化的环境中组装、拆卸和重组。第三，模型生态系统的使用——Sarracenia微生态系统——将被扩展到包括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.