International Research Fellowship Program: Herbivorous Nematodes and the Microbial Loop: Unraveling Below-ground Mechanisms Affecting Plant Production

0758674Krumins国际研究奖学金计划使美国科学家和工程师能够在国外进行9到24个月的研究。 该计划的奖项提供了联合研究的机会，以及使用独特或互补的设施，专业知识和国外的实验条件。Krumins与Wim H博士合作。土壤食物网中的养分循环对植物生产和植物群落多样性至关重要，因为土壤生物之间的直接和间接相互作用（特别是微生物循环）可能会影响植物的养分有效性。大多数土壤研究都是研究与植物根系相关的土壤食物网中微生物与其他生物隔离进行的养分循环。 在自然界中，植物和土壤生物之间的正反馈和负反馈的混合驱动养分循环，并最终驱动植物生产和群落结构。 例如，线虫的根部放牧会对植物产生负面影响（直接影响），但与放牧相关的消费者废物可能会通过营养富集对植物产生积极影响（间接影响）。 这个奖学金项目的目标是与货车德Putten博士合作开发的，是在土壤群落中整合这些间接（养分转化）和直接（草食动物）的相互作用。 在这样做的过程中，他们不仅将解决决定植物生产的重要地下机制，而且还将有助于一个重要的理论增长体，描述植物和土壤生物群之间的积极与消极相互作用的相对重要性。 这里提出的实验将同时回答以下重要问题：1。根食草动物会间接和积极地影响微生物循环的生物量和活性吗？ 2.）的情况。增强的微生物循环活动会对植物生产产生积极影响吗？ 他们将在温室实验中使用盆栽沙丘草来解决这些问题。 为了测试放牧的直接影响，PI将创建一个食草线虫密度梯度，并测量功能和群落组成中的微生物环路响应以及地下和地上生物量中的植物响应。 通过与Peter C. de Ruiter和主机，在这些实验中获得的数据将用于开发数学模型，预测植物对间接的正反馈的反应。

0758674KruminsThe International Research Fellowship Program enables U.S. scientists and engineers to conduct nine to twenty-four months of research abroad. The program's awards provide opportunities for joint research, and the use of unique or complementary facilities, expertise and experimental conditions abroad.This award will support an eighteen-month research fellowship by Dr. Jennifer A. Krumins to work with Dr. Wim H. van der Putten at the Netherlands Institute of Ecology in Heteren, The Netherlands.Nutrient cycling in soil food webs is critical to plant production and plant community diversity because direct and indirect interactions between soil organisms (especially the microbial loop) potentially affect nutrient availability to plants. Most soil research studies nutrient cycling carried out by microbes in isolation from other organisms in soil food webs associated with plant roots. In nature, a mixture of positive and negative feedbacks between plants and soil organisms drive nutrient cycling and ultimately, plant production and community structure. For instance, root grazing by nematodes can negatively affect plants (a direct effect), but consumer waste associated with grazing may positively affect plants through nutrient enrichment (an indirect effect). The goal of this fellowship project, developed in collaboration with Dr. van der Putten, is to integrate these indirect (nutrient conversion) and direct (herbivorous animals) interactions in the soil community. In doing this, they will not only resolve important below-ground mechanisms that determine plant production, but will also contribute to an important growing body of theory describing the relative importance of positive versus negative interactions between plants and soil biota. The experiment proposed here will simultaneously answer the following important questions: 1.) Will root herbivory indirectly and positively affect microbial loop biomass and activity? 2.) Will enhanced microbial loop activity positively influence plant production? They will address these questions in greenhouse experiments using potted dune grasses. To test the direct effect of grazing, the PI will create an herbivorous nematode density gradient and measure microbial loop response in function and community composition and plant response in below and above ground biomass. Through collaboration with Dr. Peter C. de Ruiter and the host, the data acquired in these experiments will be used to develop mathematical models predicting plant responses to indirect, positive feedbacks.