DISSERTATION RESEARCH: Linking phenotypic variation in plant anti-herbivore defense to spatial variation in soil nutrient pools

论文研究：将植物抗草食动物防御的表型变异与土壤养分库的空间变异联系起来

• 批准号: 1404120
• 负责人: Oswald Schmitz
• 金额: $ 2.16万
• 依托单位: Yale University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-06-01 至 2016-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1404120&HistoricalAwards=false
• 关键词: DISSERTATION; RESEARCH; Linking; phenotypic; variation

The cycling of nutrients such as nitrogen through ecosystems is a critical process that maintains biodiversity and environmental services of agricultural, urban, and natural lands. There is increasing evidence that the way plant and animal species interact with each other could control the rate of nutrient cycling. For instance, many plants respond to herbivore damage by producing defensive anti-herbivore chemicals in their tissues to ward off further damage. These defensive compounds could also slow down the nitrogen cycling rate when dead plant material enters the soil by impairing microbial decomposition. Understanding how the soil nutrient environment changes plant growth and the production of plant defenses is of critical importance to agronomists interested in lowering pesticide and fertilizer use while maximizing yield. Results of the study will be communicated to local stakeholders and small-scale farmers near the study site through a workshop and seminar designed to integrate knowledge of ecosystem dynamics into sustainable land management strategies. In addition, continuing engagement with a local township conservation commission will incorporate study results directly into land management strategies. Results will be shared through presentations at professional meetings and funding will support the mentoring of undergraduates on projects with the potential for co-authorship on publications that arise from the work.Linking genes to ecosystem function is a recent focus in ecosystem ecology, because a plant's genotype determines how it functions and thus has the potential to impact ecosystem processes. Plant genotypes are also shaped by their growing environment, however, resulting in differential trait expression across environmental conditions. Knowing how such trait plasticity connects to ecosystem functioning is fundamental to prediction of how environmental change will influence ecosystem processes like nitrogen (N) cycling. Interactions among rates of herbivory, structural anti-herbivore defensive compounds, and site fertility can all affect trait plasticity and thus can affect the connections between genes and ecosystems. These interactions will be examined manipulating the growing environment in caged raised bed garden plantings of several different genotypes of a common meadow plant, goldenrod (Solidago altissima), which innately express anti-herbivore defenses differently under different conditions. The experiment will exclude or add Melanoplus femurrubrum grasshopper herbivores and exclude or add fertilizer. The study will measure how rapidly soil microbes decompose plant leaf litter from the genotypes grown in the different herbivory and fertilizer conditions. Subsequent experiments will measure how this processing changes soil microbial communities, soil nitrogen availability, and subsequent plant growth and traits. Finally, a 15N tracer experiment will allow measurement of nitrogen cycling by tracking the amount of nitrogen in the soil and in plants after it is released by microbial decomposition. Taken together these experiments will determine whether plant genotype, the expression of plant anti-herbivore traits, or soil N level best predicts N cycling within ecosystems.

通过生态系统的氮气（例如氮）的循环是一个关键过程，可维持农业，城市和自然土地的生物多样性和环境服务。 越来越多的证据表明，动植物彼此相互作用的方式可以控制营养循环的速度。例如，许多植物通过在组织中产生防御性的抗小鼠化学物质来应对食草动物的损害，以防止进一步的损害。当死植物材料通过损害微生物分解而进入土壤时，这些防御性化合物也可能会降低氮循环速率。了解土壤养分环境如何改变植物的生长和植物防御能力对有兴趣降低农药和肥料使用的农艺师而言，同时最大化产量至关重要。该研究的结果将通过研讨会和研讨会在研究地点附近的本地利益相关者和小型农民传达，旨在将生态系统动力学知识纳入可持续土地管理策略。此外，继续与当地乡镇保护委员会的互动将直接将研究结果直接纳入土地管理策略。结果将通过在专业会议上的演讲中分享，资金将支持本科生在项目上的指导，并有可能在作品上共同创作。基因型决定了它的功能，因此具有影响生态系统过程的潜力。但是，植物基因型也受到其不断增长的环境的影响，导致环境条件下的性状差异表达。知道这种性状可塑性如何连接到生态系统功能，这是对环境变化将如何影响生态系统过程等生态系统过程的基础。草食性，结构性抗草食性防御性化合物和部位生育率之间的相互作用都会影响性状可塑性，从而影响基因与生态系统之间的联系。这些相互作用将进行检查，以操纵笼中的床床花园种植的不断增长的环境，这些植物的几种不同的基因型goldenrod（Solidago altissima）天生在不同条件下以不同的方式表达抗Herbivore防御。该实验将排除或添加黑色素质量草皮食动物，并排除或添加肥料。该研究将测量土壤微生物在不同的草食和肥料条件下生长的基因型中分解植物叶的垃圾。随后的实验将测量这种加工如何改变土壤微生物群落，土壤氮的可用性以及随后的植物生长和特征。最后，15N示踪剂实验将通过在微生物分解释放后通过跟踪土壤和植物中的氮量来测量氮循环。综上所述，这些实验将确定植物基因型，植物抗草皮动物性状的表达或土壤n水平最佳预测生态系统内的n循环。