US-Mexico Dissertation Enhancement: Changes in Community Structure and Ecosystem Processes in Response to Armored Catfish Invasion

尽管入侵性放牧生物已经在全球范围内被引入，但人们对外来食草动物对营养循环和其他关键生态系统过程的影响知之甚少。本博士论文增强项目的主要目的是研究外来装甲鲶鱼是否会改变入侵热带生态系统中原生物种的营养循环和初级生产力，降低其食物质量和数量，并减少原生无脊椎动物和鱼类的生物多样性。研究生Krista Capps在Alexander Flecker博士的指导下，将研究盔甲鲶鱼对墨西哥南部生物和文化多样性地区Grijalva-Usumacinta流域河流系统的影响。这项研究将与墨西哥圣克里斯托瓦尔德拉斯卡萨斯的南方农业学院（ECOSUR）的Rocío Rodiles-Hernández博士合作进行。本研究的成果将包括：1)评估入侵放牧生物影响的实验框架；2)了解外来装甲鲶鱼如何保留和加工营养物质；3)装甲鲶鱼入侵地点的生物和化学调查；4)通过创建和增强生物收集来增强对Grijalva-Usumacinta流域生物多样性的认识。外来物种的引入是全球物种多样性和生态系统功能面临的最大威胁之一。本研究将直接促进对外来放牧生物及其对生态系统健康影响的认识。由于甲鲶鱼的入侵与Usumacinta流域淡水渔业的崩溃有关，因此从这项研究中获得的知识也将具有广泛的管理意义。该研究小组将与墨西哥国家人类学和历史研究所合作，促进对外来装甲鲶鱼种群的管理，并将加强联合国教科文组织世界遗产帕伦克国家公园及其周围淡水生物的生物多样性知识。

Although invasive grazing organisms have been introduced throughout the globe, little is understood about the effects of exotic grazers on nutrient cycling and other key ecosystem processes. The major objectives of this doctoral dissertation enhancement project are to examine whether exotic armored catfish alter nutrient cycling and primary productivity, decrease food quality and quantity for native species, and reduce native biodiversity of invertebrates and fishes in invaded tropical ecosystems. Graduate student Krista Capps, under the mentorship of Dr. Alexander Flecker, will study the impacts of armored catfishes on rivers systems in the Grijalva-Usumacinta watershed, a biologically and culturally diverse region in southern Mexico. The research will be done in collaboration with Dr. Rocío Rodiles-Hernández of the Colegio de la Frontera Sur (ECOSUR) in San Cristobal de las Casas, Mexico. The products generated by this study will include: 1) an experimental framework to assess the effects of invasive grazing organisms, 2) an understanding of how exotic armored catfish retain and process nutrients, 3) biological and chemical surveys of armored catfish invasion sites, and 4) enhanced biodiversity knowledge of the Grijalva-Usumacinta watershed through the creation and enhancement of biological collections.The introduction of non-native species is one of the greatest threats to species diversity and ecosystem function throughout the world. This study will directly contribute to the general understanding of exotic grazing organisms and their effects on ecosystem health. Since armored catfish invasion has been linked to the collapse of freshwater fisheries in the Usumacinta watershed region, knowledge derived from this study will also have extensive management implications. The research team will collaborate with the Mexican National Institute of Anthropology and History to promote management of exotic armored catfish populations, and will enhance the biodiversity knowledge of freshwater organisms in and around Palenque National Park, a UNESCO World Heritage Site.