International Research Fellowship Program: Ecological Consequences of Large-Herbivore Declines under Different Rainfall Regimes

0852961PringleThis award is funded under the American Recovery and Reinvestment Act of 2009（Public Law 111-5）.The International Research Fellowship Program enables U.S. Scientists and engineers to conduct nine to twenty-four months of research abroad. 该计划的奖项提供了联合研究的机会，以及使用独特或互补的设施，专业知识和国外的实验条件。普林格尔将与国际昆虫病理学和生态学中心（CIPE）的法比安哈斯博士、肯尼亚国家博物馆的查尔斯·瓦鲁伊博士和肯尼亚国家博物馆的M.最近的研究表明，大型哺乳动物食草动物可能是？强大的互动？它们的消失将促使生物群落发生重大变化。本项目旨在记录和解释短期（2-3年）的反应，植物和无脊椎动物群落的排斥有蹄类食草动物在肯尼亚稀树草原，并研究这些反应是如何取决于降雨量的变化。这是通过一项独特的实验来完成的，该实验采用四种1公顷处理：完全排除（去除所有大于4公斤野兔的食草动物）、排除所有大于6公斤堤防的食草动物、仅排除大型食草动物（大象和长颈鹿）以及无围栏控制（所有动物都在场）。这些处理在自然降雨梯度的三个水平上各重复三次。项目人员正在检验四个具体假设。我：草食动物的排斥改变了个别植物的适口性，提高招聘，减少物种的均匀度，并增加栖息地的结构复杂性。II：通过对植物的这些影响，草食动物排斥导致草食性和肉食性节肢动物的总生物量增加。第三章：个体节肢动物的间接反应各不相同，但取决于（a）饮食的广度和寄主植物的偏好，（B）觅食策略，（c）捕食的脆弱性。第四，直接和间接影响的强度与降雨量呈负相关。人类正在减少全球大型食草动物的数量，气候变化预示着降水模式的巨大变化。然而，没有人知道这些变化将如何影响生物多样性和生态功能的标志性景观，如非洲热带草原和黄石生态系统。产生这些知识将揭示大型哺乳动物如何影响生态动态以及这些影响如何受到环境背景的调节的基本事实。它还将为预测在快速变化的世界中大型哺乳动物减少和灭绝的后果提供基础。到目前为止，大型哺乳动物迁移反应的测量一直是特殊的和机会主义的，提供的机制来解释的反应往往是推测性的。此外，在物种丰富的有蹄类动物公会进行的少数排斥实验大多是？全部或全部都没有？这意味着无法确定特定物种或亚群的影响，而我们基于顺序大小的排除方法将隔离这些影响。最后，这个实验是第一个结合联合收割机大型草食动物排斥与复制跨越多个层次的环境梯度，这是一致的，最近呼吁生态学家解决物种相互作用的上下文依赖。在开发人力资本和国际合作方面，该项目支持来自肯尼亚农村当地社区的五名全职研究助理。他们的就业为他们提供了宝贵的、可转移的技能（肯尼亚本土生物多样性的鉴定、数据输入和计算机培训、管理和团队合作经验）。这些人也来自不同的种族群体和宗教，在一个被种族冲突撕裂的地区（最近是2008年1月）;共同努力巩固了克服种族差异的纽带。将带领当地人及其子女图尔斯实验设施，使他们能够在教育环境中与生物多样性互动，这将促进该区域的环境管理。该项目还涉及长期独立运作的肯尼亚三个研究机构（以及美国和加拿大的三所大学）之间的合作;这种合作将建立内部和国际伙伴关系和能力，以促进未来的共同努力。该项目还为今后对该地区鲜为人知的无脊椎动物的研究奠定了基础。最后，将在肯尼亚当地媒体和万维网上发表供非科学受众阅读的短文，传播这项工作对养护和管理的影响。

0852961PringleThis award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).The International Research Fellowship Program enables U.S. scientists and engineers to conduct nine to twenty-four months of research abroad. The program's awards provide opportunities for joint research, and the use of unique or complementary facilities, expertise and experimental conditions abroad.This award will support a twenty-four-month research fellowship by Dr. Robert M. Pringle to work with Dr. Fabian Haas at the International Centre for Insect Pathology and Ecology (CIPE), with Dr. Charles Warui at the National Museums of Kenya, and with Dr. M. Kinnaird at the Mpala Research in Kenya.Recent studies suggest that large mammalian herbivores may be ?strong interactors? whose removal will precipitate major changes in biological communities. This project aims to document and explain the short-term (2-3 year) responses of plant and invertebrate communities to the exclusion of ungulate herbivores in a Kenyan savanna, and also to examine how these responses are contingent upon variability in rainfall. This is being done using a unique experiment with four 1-ha treatments: total exclusion (removal of all herbivores larger than 4-kg hares), exclusion of all herbivores larger than 6-kg dik-diks, exclusion only of megaherbivores (elephants and giraffes), and unfenced control (all animals present). These treatments are each replicated three times at three levels of a natural rainfall gradient. Project personnel are testing four specific hypotheses. I: Herbivore exclusion alters the palatability of individual plants, enhances recruitment, reduces species evenness, and increases structural complexity at the habitat level. II: Via these effects on plants, herbivore exclusion leads to increased total biomass of both herbivorous and carnivorous arthropods. III: Indirect responses of individual arthropod species vary, but depend on (a) diet breadth and host-plant preference, (b) foraging strategy, and (c) predation vulnerability. IV: The strength of both direct and indirect effects is negatively correlated with rainfall. Humans are reducing large-herbivore populations worldwide, and climate change promises dramatic changes in precipitation patterns. Yet nobody knows how these changes will affect biodiversity and ecological function in iconic landscapes such as African savannas and the Yellowstone ecosystem. Generating this knowledge will reveal fundamental truths about how large mammals influence ecological dynamics and how these influences are modulated by environmental context. It will also provide a basis for predicting the consequences of large-mammal declines and extinctions in a rapidly changing world. To date, measurements of responses to large-mammal removal have been idiosyncratic and opportunistic, and the mechanisms offered to explain underlying the responses are often speculative. Moreover, the few exclusion experiments conducted in species-rich ungulate guilds have mostly been ?all or none,? meaning that the effects of particular species or subgroups cannot be identified, whereas our sequential size-based exclusion approach will isolate these effects. Finally, this experiment is the first to combine large-herbivore exclusion with replication across multiple levels of an environmental gradient, which is consistent with recent calls for ecologists to address the context-dependence of species interactions. In terms of developing human capital and international collaboration, this project supports five full-time research assistants from local communities in rural Kenya. Their employment provides them with valuable, transferable skills (identification of native Kenyan biodiversity, data entry and computer training, management and teamwork experience). These men are also from different ethnic groups and religions in a region torn (as recently as January, 2008) by ethnic strife; working together cements bonds that overcome ethnic differences. Local people and their children will be taken on guided tours of the experimental facilities, allowing them to interact with biodiversity in an educational setting, which will promote environmental stewardship in the region. This project also involves collaboration among three research institutions in Kenya (as well as three universities in the US and Canada) that have long operated separately; this collaboration will build intra- and international partnerships and capacity that will facilitate future joint endeavors. The project also lays a foundation for future work on the poorly known invertebrates of this region. Lastly, the conservation and management implications of the work will be disseminated in short essays for non-scientific audiences to be published both in local Kenyan media and on the worldwide web.