DISSERTATION RESEARCH: Understanding the hidden roles of parasites in ecosystem processes

在大多数生态系统中，寄生虫构成了生物多样性的很大一部分，可以对其宿主的个人、种群和社区产生强烈的影响。尽管寄生虫无处不在，但由于生态系统生态学和疾病研究之间的整合很少，因此寄生虫在生态系统过程中的作用，如能量和物质的流动，在很大程度上仍不清楚。这项建议的中心目标是研究寄生虫对淡水中两个基本生态系统过程的影响？养分循环和初级生产。这项拟议的研究将首先量化吸虫寄生虫感染对蜗牛宿主的两个功能特征(觅食和养分排泄)的影响，然后使用现实的室外中隔实验来量化吸虫影响营养循环和初级生产的直接和间接机制。总的来说，这项研究将有助于促进对寄生虫在生态系统过程中的作用的概念性理解，鉴于持续出现的疾病、自由生活生物多样性的丧失以及新宿主的引入导致寄生虫群落的变化，这是一个紧迫的主题。联合-PI将通过实施侧重于淡水生态和全球变化的有效的K-12科学课程，建立在社区教育和外联的已证实记录的基础上。该课程新颖地使用了教室中观实验，利用1个L玻璃瓶，其中包含野外收集的池塘生物，以创建微型淡水生态系统，随后这些生态系统受到两种广泛形式的全球变化的影响：化肥造成的营养污染和非本地蜗牛形式的入侵物种。学生将密切跟踪他们的中观系统的发展，同时获得关于全球变化问题和中小学水平的科学标准(例如，假设检验和批判性思维)的知识。与外展活动相结合，该中心将通过在加州门多西诺县霍普兰研究和推广中心在夏季实地考察期间为四名本科生提供研究机会，加强为代表性不足的学生提供服务的持续努力。

Parasites comprise a large fraction of biodiversity within most ecosystems and can exert strong effects on individuals, populations and communities of their hosts. Despite their ubiquity, the roles of parasites in ecosystem processes, such as fluxes of energy and matter, remain largely unknown due to the rarity of integration between ecosystem ecology and disease research. The central aim of this proposal is to examine the influences of parasites on two fundamental ecosystem processes in freshwaters ? nutrient cycling and primary production. The proposed research will first quantify the effects of infection by trematode parasites on two functional traits of snail hosts (grazing and nutrient excretion) and then use a realistic outdoor mesocosm experiment to quantify the direct and indirect mechanisms through which trematodes influence nutrient cycling and primary production. Collectively, this research will help to advance a conceptual understanding of the roles of parasites in ecosystem processes, which is a pressing topic in light of changes in parasite communities driven by ongoing disease emergence, losses of free living biodiversity, and introductions of novel hosts.The Co-PI will build upon a proven track record of community education and outreach by implementing an effective K-12 science curriculum that focuses on freshwater ecology and global change. The curriculum is novel in its use of a classroom mesocosm experiment utilizing 1 L glass jars containing field-collected pond organisms to create miniature freshwater ecosystems that are subsequently impacted by two widespread forms of global change: nutrient pollution from fertilizer and invasive species in the form of non-native snails. The students will closely track the development of their mesocosms while gaining knowledge on both global change issues and science standards at the elementary and middle school levels (e.g., hypothesis testing and critical thinking). In conjunction with outreach, the Co-PI will enhance ongoing efforts to serve underrepresented students by providing research opportunities to four undergraduates during the summer field seasons at the Hopland Research and Extension Center in Mendocino County, California.