Collaborative Research: Effects of Nutrient Stress on a Co-evolved Food Web

生态学家面临的一个主要挑战是了解环境压力对群落结构和功能的影响。这项研究将确定一种新的应激源-增加大气氮沉积-是如何改变与北方猪笼草，瓶子草相关的碎屑为基础的食物网的动态。提出了三种不同类型的分析，以解决与猪笼草群落的营养动态相关的假设。一个实地“脉冲”实验将操纵食物网的物种组成和氮的来源。氮同位素将被用来揭示氮的运动来自人为来源和猎物。温室“压力”实验将测量不同食物网结构对猪笼草营养吸收和生长的影响。实验结果将用于开发社区组装和食物网动态模型。拟议的研究将揭示共同进化系统的人为压力的重要性，并有助于更深入地了解自上而下和自下而上的力量对非平衡组合动态的对比效应。这项研究将产生通用模型，可应用于其他生态社区经历新的压力。它将涉及研究生和本科生在监督和独立的研究。

A major challenge for ecologists is to understand the effects that environmental stressors have on community structure and function. This research will determine how a novel stressor - increased atmospheric deposition of nitrogen - is altering the dynamics of the detritus-based food web associated with the northern pitcher plant, Sarracenia purpurea. Three different types of analyses are proposed to address hypotheses related to the trophic dynamics of pitcher plan communities. A field 'pulse' experiment will manipulate the species composition of the food web and the source of nitrogen. Nitrogen isotopes will be used to reveal the movement of nitrogen derived from anthropogenic sources and from prey. A greenhouse 'press' experiment will measure the effects of different food web structures on nutrient uptake and growth of pitcher plants. Experimental results will be used to develop models of community assembly and of food web dynamics. The proposed research will reveal the importance of anthropogenic stressors on co-evolved systems and contribute to a deeper understanding of the contrasting effects of top-down and bottom-up forces on the dynamics of non-equilibrial assemblages. The research will result in general models that can be applied to other ecological communities experiencing novel stressors. It will involve graduate and undergraduate students in supervised and independent research.