Collaborative Research: Effects of forest fragmentation on Lepidopteran herbivores of contrasting diet breadth

栖息地被分割成更小、更孤立的部分，可能会让动物生活在食物资源不足的地区。对于那些饮食专家来说，这个问题尤其严重。这些专家可能会从栖息地中消失，它们的消失会对其他物种产生连锁反应，从而进一步改变生态群落的组成。这个项目将检验一些假说，这些假说被用来解释来自破碎森林的特殊食草动物数量的减少。这项研究对于理解土地利用的变化或破坏栖息地的其他干扰如何影响生物多样性和生态系统的完整性具有重要意义。本项目将以不同饵料需求品种的蝴蝶幼虫为研究对象。它们对特定植物种类的依赖以及它们作为鸟类猎物的角色将在康涅狄格州的40个森林地点进行研究，这些地点的基本生态相互作用是众所周知的。除了分析对过去森林破碎化的反应外，保护毛毛虫免受捕食的实验将有助于量化食物资源的重要性。这项研究将提高对受人类影响的天然食物网的理解，并可以指导未来的森林管理。该项目还将为森林生态学的学生提供研究培训，这将加强科学队伍。森林破碎化很可能在很大程度上改变物种之间的相互作用，一个反复出现的模式是小森林碎片食物网中饮食专家的流失。该项目侧重于鳞翅目幼虫、寄主植物和鸟类捕食者组成的复杂的三营养生态网络，将建立自下而上和自上而下的机制如何改变森林碎片中专业食草动物的绝对和相对丰度。该项目将结合植物-鳞翅目联系和区域森林破碎化的大量现有数据、40个地点植物和毛虫的新数据、实地实验和实验室对毛虫食性广度和生长响应的分析，量化温带落叶林中寄主植物可用性和捕食对鳞翅目幼虫食性的影响。这种详细的、多营养的方法将加强对由于碎片化而导致的营养网络变化的机制理解。这项工作将产生四个更广泛的影响：1)培训未来的科学家，2)招募代表性不足的群体，3)科学领域的公共宣传，4)改善科学基础设施。

The fragmentation of habitats in to smaller and more isolated pieces can leave animals in areas that have insufficient food resources within reach. This problem is particularly acute for those species that are dietary specialists. These specialists may then be lost from the habitats, and their loss can have cascading effects on other species that may further alter the composition of ecological communities. This project will test alternative hypotheses that have been proposed to explain declines in specialist herbivores from fragmented forests. This research is important in understanding how changes in land use or other disturbances that fragment habitats will affect biodiversity and the integrity of ecosystems. The project will focus on butterfly larvae of species with different diet requirements as model study organisms. Their dependence on particular plant species and their role as prey for birds will be studied in 40 forest sites in Connecticut where the basic ecological interactions are well known. In addition to analysis of response to past forest fragmentation, experiments protecting caterpillars from predation will help quantify the importance of food resources. The study will improve understanding of natural food webs subject to human impacts and can guide future forest management. This project will also provide research training for students in forest ecology that will strengthen the scientific workforce.Forest fragmentation is likely to substantially modify interactions among species and a recurrent pattern is the loss of dietary specialists from food webs in small forest fragments. Focusing on a complex, tri-trophic ecological network of larval Lepidoptera, their hostplants and avian predators, the project will establish how bottom-up and top-down mechanisms alter the absolute and relative abundance of specialist herbivores in forest fragments. The project will combine extensive extant data on plant-Lepidoptera associations and regional forest fragmentation, new data on plants and caterpillars at 40 sites, field experiments, and lab analyses on caterpillar diet breadth and growth response to quantify effects of host plant availability and predation on the diet specificity of lepidopteran larvae in temperate deciduous forests. This detailed, multi-trophic approach will enhance mechanistic understanding of changes in trophic networks due to fragmentation. Four broader impacts will result from this work: 1) training future scientists, 2) recruiting underrepresented groups, 3) public outreach in science and 4) improving scientific infrastructure.