Dissertation Research: Quantifying the role of mixotrophic feeding in aquatic food webs

水生生态学的基本原则之一是，藻类通过光合作用的初级生产，支持所有水生食物网，并负责地球上大约一半的初级生产力。实际上，许多藻类是混合营养型的；也就是说，它们能够通过异养消耗细菌、其他藻类，甚至是从陆地来源输送到湖泊的溶解和颗粒物质来补充光合作用的产生。本论文将使用天然稳定同位素示踪剂来量化由于光合作用和混合营养作用而产生的藻类产量。来自实验室和野外实验的混合营养估计将与美国大陆混合营养丰度的预测模型相结合，以评估混合营养在淡水食物网中的重要性。混合营养是一种潜在的重要自然过程，人们已经知道它有一段时间了，但对它的理解却很少。这项研究的结果将使水生食物网的描述和模型更加准确。这方面的知识将为淡水生态系统的变化提供更好的预测——比如有毒藻华的发生——这些变化越来越暴露于人类引起的变化之中。研究人员将从服务不足的群体中招募本科生，通过正在进行的SUNY-ESF项目参与研究。此外，这项研究将在SUNY-ESF的蔓越莓湖生物站进行，该站在整个夏季都是一个活跃的教学校园。在该站注册课程的学生将参与研究。

One of the basic tenets of aquatic ecology is that primary production by algae, through the process of photosynthesis, supports all aquatic food webs and is responsible for approximately half of the primary productivity on earth. In reality, many algal species are mixotrophic; that is, they are capable of supplementing photosynthetic production with heterotrophic consumption of bacteria, other algae, or even dissolved and particulate material transported into lakes from terrestrial sources. The proposed dissertation research will use natural stable isotopic tracers to quantify the amounts of algal production due to photosynthesis versus mixotrophy. Estimates of mixotrophy from laboratory and field experiments will be combined with predictive models of mixotroph abundance across the continental United States to evaluate the importance of mixotrophy in freshwater food webs.Mixotrophy represents a potentially important natural process that has been known for some time, but is poorly understood. Results from this study will allow more accurate descriptions and models of aquatic food webs. This knowledge will provide better predictions of changes to freshwater ecosystems - such as the occurrence of toxic algal blooms - that are increasingly exposed to human-induced modifications. The investigators will recruit undergraduates from under-served groups to participate in the research through ongoing SUNY-ESF programs. In addition, the research will be carried out at SUNY-ESF's Cranberry Lake Biological Station, which is an active teaching campus throughout the summer. Students enrolled in courses at the station will participate in the study.