DISSERTATION RESEARCH: Effects of multiple invasive species on nutrient cycling in Lake Seminole: effects of warmer winters on ecosystem dynamics

人类活动正在引起全球物种分布的重大变化。这些变化导致了植物和动物的新组合的发展，因为新物种入侵了广泛的生态系统。在许多情况下，多个物种侵入同一地区，它们对生态系统进程的相互影响尚未得到充分了解。该项目的总体目标是调查多种入侵者对格鲁吉亚和佛罗里达边界的塞米诺尔湖营养循环的相互影响。实验将记录来自亚洲的一种高产水生植物黑藻与大量亚洲蛤蜊河蚬和两种新建立的蜗牛物种（来自南美洲的斑点福寿螺和来自佛罗里达的沼泽福寿螺）共同生活的影响。这些实验的目的是模拟自然条件下的光和温度，并确定在营养吸收率的差异，存储和释放的黑藻与和没有蚬和两个福寿螺物种。为了确定由于其他非本地物种的存在而引起的水生植被的丰度和分布的大规模变化，将开发遥感方法来跟踪非本地水生植被的快速变化。将把中围生态系统实验和遥感分析的结果纳入一个一般概念模型，以预测随着这些入侵物种向北迁移到其他湖泊和河流，未来可能对养分循环产生的影响。最近的气候变化和人类增加的生物迁移正在将许多物种分散到新的地点，导致许多生态系统中出现新的物种组合。了解非本地水生植物和动物如何相互作用，可以预测它们对特定生态系统服务的影响，如营养循环，提供可持续的高质量饮用水供应，以及休闲划船和捕鱼。塞米诺尔湖最近的入侵福寿螺，在那里已经建立了另外两个丰富的入侵物种（黑藻和蚬），提供了一个独特的机会，在早期阶段研究多物种入侵，并调查对生态系统服务的影响，特别是它们对水质的影响。塞米诺尔湖目前在养分和污染物储存以及向下游社区提供高质量水方面发挥着关键作用。然而，人们对湖泊内入侵物种的相互作用或综合影响知之甚少，也不知道最近的引入将如何影响湖泊生产和营养循环。该项目将有助于填补这些知识空白，并向地方和区域利益攸关方通报入侵物种对湖泊生态系统的影响。将组织一次研讨会，以促进与利益攸关方就入侵物种的影响进行沟通。该概念模型将有助于建立一个预警网络，告知居民如何减少入侵物种的传播、潜在的毒性风险和野生动物疾病。当地学生将受益于直接参与研究和讲习班。

Human activities are causing major changes in species distributions globally. These changes have led to the development of new combinations of plants and animals as new species have invaded a wide range of ecosystems. In many cases, multiple species have invaded the same areas, and their interactive effects on ecosystem processes are not well understood. The overarching objective of this project is to investigate the interactive effects of multiple invaders on nutrient cycling in Lake Seminole, on the border of Georgia and Florida. Experiments will document the effects of a highly productive species of aquatic plant from Asia, Hydrilla verticillata, living together with an abundant Asian clam, Corbicula fluminea, and two newly established snail species (Pomacea maculata, from South America and Pomacea paludosa from Florida). These experiments are designed to simulate natural conditions of light and temperature and determine differences in rates of nutrient uptake, storage, and release by Hydrilla with and without Corbicula and the two Pomacea species. To determine larger scale changes in abundance and distribution of aquatic vegetation due to the presence of the other non-native species, remote sensing methods will be developed for tracking rapid changes among non-native aquatic vegetation. Results from mesocosm experiments and remote sensing analyses will be integrated into a general conceptual model to forecast likely future impacts on nutrient cycling as these invasive species move northward to other lakes and rivers. Recent climate change and increased organism movement by humans are dispersing many species into new locations, resulting in novel species combinations in many ecosystems. Understanding how non-native aquatic plants and animals interact allows for projection of their effects on specific ecosystem services, such as nutrient cycling, provision of sustainable supplies of high-quality drinking water, and recreational boating and fishing. The recent invasion of Lake Seminole by Pomacea, where two other abundant invasive species (Hydrilla and Corbicula) were already established, provides a unique opportunity to study multi-species invasions at an early stage and to investigate effects on ecosystem services, specifically their impact on water quality. Lake Seminole currently plays a critical role in nutrient and contaminant storage as well as in providing high-quality water to downstream communities. However, little is known about the interactions or combined effects of invasive species within the lake, nor how recent introductions will affect lake production and nutrient cycling. This project will help to fill these knowledge gaps and to inform local and regional stakeholders of the effects of invasive species on lake ecosystems. A workshop will be organized to facilitate communication with stakeholders on the effects of invasive species. The conceptual model will help to create an early warning network to inform residents on how to reduce the spread of invasive species, the potential risks of toxicity, and wildlife diseases. Local students will benefit from direct participation in research and workshops.