LTREB: KLEE- scaling up and out at the Kenya Long-term Exclosure Experiment

半干旱生态系统覆盖了世界的大部分地区。在非洲，这些稀树大草原支撑着地球上一些最壮观的大型哺乳动物生物多样性。非洲稀树草原已被深入研究，大量文献记录了放牧和土著食草动物对这些生态系统植被的影响。尽管进行了广泛的研究，但令人惊讶的是，人们对野生动物、家畜、林下植被和木本植被之间的相互作用知之甚少。肯尼亚长期封闭实验（KLEE）是第一个受控的，复制的尝试，以检查这些相互作用，这些球员之间共存的潜力，以及这种共存的限制。到目前为止，这种对牲畜和大型哺乳动物食草动物的三个公会的控制性排斥已经回答了关于一个主要的半干旱生态系统的生态学的各种问题。该更新提案将支持这项长期研究的第13-17年。下一阶段的目标是继续研究竞争、补偿和营养级联，同时启动关于树木密度变化的原因和后果的受控实验，并检查草食动物引起的和实验操纵的树木密度变化的生态系统后果。该项目继续为世界上最重要的生物群落之一的牧场管理和生物多样性保护提供重要信息。该项目是高度合作的，接待了来自多个美国和非洲机构的高级和初级研究人员。肯尼亚和美国的研究生都将参加拟议的研究并接受培训; KLEE研究将继续举办本科生研究，沿着来自肯尼亚、英国和美国的课堂访问。研究人员与当地牧民团体和土地所有者密切互动，以支持当地在土地和资源管理方面的努力。该奖项由NSF国际科学与工程办公室共同资助。

Semi-arid ecosystems cover large portions of the world. In Africa, these savannas support some of the most spectacular large mammal biodiversity on the planet. African savannas have been studied intensively, and considerable literature documents effects of both cattle grazing and indigenous herbivores on the vegetation of these ecosystems. Despite this extensive research, surprisingly little is known about interactions among wildlife, domestic livestock, understory vegetation and woody cover. The Kenya Long-term Exclosure Experiment (KLEE) is the first controlled, replicated attempt to examine these intereactions, the potential for co-existence among these players, and the limits to this co-existence. To date, this controlled exclusion of livestock and three guilds of large mammalian herbivores has answered diverse questions about the ecology of a major, semi-arid ecosystem. This renewal proposal will support years 13-17 of this long-term study. The goals of the next phase are to continue studies of competition, compensation, and trophic cascades while initiating controlled experiments on the causes and consequences of variation in tree densities and to examine the ecosystem consequences of herbivore-induced and experimentally manipulated changes in tree density.In addition to addressing fundamental questions in ecological science, this project continues to contribute essential information for rangeland management and biodiversity conservation in one of the world's most important biomes. The project is highly collaborative and hosts both senior and junior investigators from multiple US and African institutions. Both Kenyan and US graduate students will participate in, and receive training from, the proposed research; the KLEE study will continue to host undergraduate student research as well, along with classroom visits from Kenya, the United Kingdom and the US. Researchers interact closely with local pastoralist groups and landowners to support local efforts in land and resource management. This award is co-funded by NSF's Office of International Science and Engineering.