DISSERTATION RESEARCH: The alteration of landscape nutrient flows by human-induced increases in generalist omnivores

论文研究：人类引起的杂食动物增加对景观养分流的改变

• 批准号: 0909965
• 负责人: Robert Holt
• 金额: $ 1.15万
• 依托单位: University of Florida
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-05-15 至 2012-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0909965&HistoricalAwards=false
• 关键词: DISSERTATION; RESEARCH; alteration; landscape; nutrient

All organisms require nutrients, such as nitrogen, potassium, and phosphorus, and movements of these nutrients among habitats may fundamentally alter their availability for plant growth, and ultimately for the animals dependent upon these plants. Animals can be important avenues of nutrient movement across space. Humans have altered these nutrient flows, both by eliminating some species, and by introducing others which can lead to many direct and indirect impacts on ecological function. Feral swine - a species which was first introduced to the New World by the Spaniards and are now widespread and abundant - is a classic example of a species that can potentially have large impacts upon nutrient flows among habitats. A detailed study of impacts of feral pigs upon ecosystem nutrient flows is being undertaken in the Lower Suwannee National Wildlife Refuge, located on the Gulf Coast of Florida. The landscape consists of forested islands interlaced in salt marsh. The pigs use the islands as refuges, and their intense use of these areas has led to high deposition of fecal material in the island forest habitats. Surveys revealed higher nutrient levels in the island forest soil compared to mainland forest soil, and there appear to be considerable impacts upon local plant communities. Exclosures have been set up to determine whether feral hogs are indeed responsible for increased nutrients in these refuges areas, and to examine their impact on the plants. To determine the source of the deposited nutrients, the diet of the hogs is being determined through analysis of fecal and bone samples. Genetic analysis of DNA in the feces will permit an estimation of population size and, combined with the effect the population has on nutrient deposition, will allow a 'per hog' expression of the impact of feral hogs on the nutrient flows. Feral and wild pigs are found globally and are often very abundant in the southeastern U.S.A. Refuge and park managers consider them to be very destructive, but past work has not quantified the magnitude of their impacts on nutrient flows, even though it is clear that they can profoundly alter local ecological processes. The results of this study should have wide applicability, providing basic knowledge that can assist management of many disturbed ecosystems. The project also enriches science education. Undergraduates will be involved in both in the fieldwork and in laboratory analysis. Students will be encouraged to develop their own related projects. One student will examine the imprint of periodic food scarcity as well as disease recorded in tooth enamel and bones. The student will eventually apply the results to the archaeological remains of human populations. One unusual aspect of the educational experience provided by involvement with this project is that students will be interacting with a wide range of non-academic users of the refuge, for instance by the preparation of educational materials and Powerpoint presentations made available to the general public via organizations like the Friends of Lower Suwannee and the National Wildlife Refuge system.

所有生物都需要营养物质，如氮、钾和磷，这些营养物质在栖息地之间的移动可能从根本上改变它们对植物生长的可利用性，并最终改变依赖这些植物的动物的可利用性。动物是营养物质跨空间流动的重要途径。人类通过消灭一些物种和引入其他物种改变了这些营养流动，这可能对生态功能产生许多直接和间接的影响。野猪——一种由西班牙人首先引入新大陆的物种，现在分布广泛，数量众多——是一种可能对栖息地之间的营养流动产生巨大影响的物种的典型例子。一项关于野猪对生态系统养分流动影响的详细研究正在位于佛罗里达州墨西哥湾沿岸的下苏万尼国家野生动物保护区进行。景观由盐沼中交错的森林岛屿组成。猪把这些岛屿作为避难所，它们对这些地区的大量使用导致了岛上森林栖息地粪便物质的大量沉积。调查显示，与大陆森林土壤相比，岛屿森林土壤的营养水平更高，似乎对当地植物群落产生了相当大的影响。已经设立了隔离措施，以确定野猪是否确实对这些保护区的营养增加负有责任，并检查它们对植物的影响。为了确定沉积的营养物质的来源，正在通过分析粪便和骨骼样本来确定猪的饮食。对粪便中的DNA进行遗传分析可以估计种群规模，并结合种群对营养物质沉积的影响，可以用“每头猪”来表达野猪对营养物质流动的影响。野猪和野猪在全球范围内都有发现，在美国东南部通常非常丰富。保护区和公园的管理人员认为它们具有很强的破坏性，但过去的工作没有量化它们对营养物质流动的影响程度，尽管很明显它们可以深刻地改变当地的生态过程。本研究结果应具有广泛的适用性，为许多受干扰生态系统的管理提供基础知识。该项目还丰富了科学教育。本科生将参与实地工作和实验室分析。学生将被鼓励开发他们自己的相关项目。一名学生将研究周期性食物短缺的印记，以及牙釉质和骨骼中记录的疾病。学生最终将把结果应用于人类的考古遗迹。参与这个项目所提供的教育体验的一个不同寻常的方面是，学生将与保护区的广泛的非学术用户互动，例如通过准备教育材料和Powerpoint演示文稿，通过像下苏旺尼之友和国家野生动物保护区系统这样的组织向公众提供。