DISSERTATION RESEARCH: Soil resource variability as a driver of interactions within, and emergent properties of, tritrophic ecological networks

论文研究：土壤资源变异性作为三营养生态网络内部相互作用及其新兴特性的驱动因素

• 批准号: 1600961
• 负责人: Sharon Strauss
• 金额: $ 1.92万
• 依托单位: University of California-Davis
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-06-01 至 2018-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1600961&HistoricalAwards=false
• 关键词: DISSERTATION; RESEARCH; Soil; resource; variability

A key goal in ecology is understanding how and why environmental variation shapes species interactions. Food webs describe the feeding relationships between organisms, and illustrate the ecological roles of plants and animals in natural communities. Food webs also describe how the entire suite of feeding interactions might function. Understanding how and why food webs differ between places is important because it can help predict ecological impacts of environmental change such as species loss or habitat change. In this project, researchers will study how changes in soil nutrients cause differences in food webs. The research focuses on the feeding interactions between plants and caterpillars, and between caterpillars and their predators. By documenting "who eats whom" in Northern California soils of low versus high fertility, this project will be able to describe complex food webs and ask how these webs are different across soil types. Because most of our understanding of this topic comes from agricultural ecosystems that have soils impacted by fertilizer, this project will provide new insights as it is based on soils that naturally vary in fertility. This research will involve several undergraduate students and an ecology club. Variation in soil resources is a ubiquitous form of environmental heterogeneity, with strong direct and indirect effects on organismal traits and species interactions. Multiple theories address the effects of resource level on trophic interactions: the Resource Availability Hypothesis (RAH) suggests that resource availability should shape plant traits and, consequently, their quality to herbivores; in turn, the Slow Growth, High Mortality (SGHM) and High Performance, High Mortality Hypotheses (HPHM) relate plant quality to interactions between herbivores and natural enemies. Based on these theories, this research will disentangle the interacting roles of predation and nutritive and defensive plant traits in shaping plant-caterpillar-top predator tri-trophic interactions. Using a natural mosaic of low fertility serpentine and higher fertility non-serpentine soils in California, this project will build exclusion cages to assess how top-predators affect plant-caterpillar interactions across different soil types. Plant nutritive and defensive traits will be measured simultaneously to disentangle the relative importance of traits and predation in driving food web structure across different resource contexts. Together, these experiments will advance our understanding of how and why species interactions vary across heterogeneous landscapes.

生态学的关键目标是了解环境变化如何以及为什么塑造物种相互作用。食物网描述了生物体之间的喂养关系，并说明了自然界动植物的生态作用。食物网还描述了整个喂养相互作用的套件如何起作用。了解地方之间的食物网是如何以及为什么在地方之间的重要性很重要，因为它可以帮助预测环境变化的生态影响，例如物种丧失或栖息地变化。在这个项目中，研究人员将研究土壤养分的变化如何导致食物网的差异。该研究的重点是植物与毛毛虫之间以及毛毛虫及其捕食者之间的饲料相互作用。通过记录在北加州北加州土壤中的“谁吃谁”，该项目将能够描述复杂的食物网，并询问这些网络在土壤类型之间的不同之处。因为我们对该主题的大多数理解都来自具有肥料影响的土壤的农业生态系统，因此该项目将提供新的见解，因为它基于自然在生育上变化的土壤。这项研究将涉及几个本科生和一个生态俱乐部。 土壤资源的变化是环境异质性的一种普遍形式，对有机特征和物种相互作用具有强烈的直接和间接影响。多种理论解决了资源水平对营养相互作用的影响：资源可用性假设（RAH）表明，资源可用性应塑造植物特征，从而塑造其对食草动物的质量；反过来，缓慢的生长，高死亡率（SGHM）和高表现，高死亡率假设（HPHM）将植物质量与草食动物与自然敌人之间的相互作用联系起来。基于这些理论，这项研究将消除捕食和营养和防御性植物特征在塑造植物 - 孢子式捕食者捕食者三营相互作用中的相互作用。该项目使用加利福尼亚州低生育力的天然镶嵌和较高的生育非serpentine土壤，该项目将建立排除笼子，以评估顶级预言如何影响不同土壤类型的植物 - 甲状腺肿相互作用。将同时衡量植物营养和防御性状，以消除特征和捕食在跨不同资源环境驱动食物网络结构中的相对重要性。这些实验将共同提高我们对种类相互作用在异质景观之间的理解和为什么的理解。