Establishment of large-scale herbivore exclosures

虽然我们有时对物种灭绝的原因有详细的了解，但关于其对生态系统的影响却缺乏信息。我和我的研究小组致力于了解大型食草动物的灭绝是如何影响非洲大草原上的植物种群的。我们在肯尼亚莱基皮亚的研究地点构成了研究这种灭绝后果的理想系统。Laikipia由10000平方公里的私人财产组成，其中每个财产都与三种情况中的一种有关，反映了脊椎动物群落典型的渐进灭绝，规模偏大：1)大象（~3000公斤）+黑斑羚（~70公斤）+ dik-dik（~5公斤）；2)黑斑羚+ dik-dik；或者只吃丁丁。在世界范围内，草食植物的影响往往取决于非生物因素，而东非降雨量的高空间变化模糊了植物种群动态的驱动因素。因此，解决这些问题的第一步是通过实验解开大型食草动物、降雨及其在形成植物种群中的相互作用的相对作用。该资金申请与NSERC发现资助提案同时提交。在我的“发现”号提案中，我寻求对一套电气化围栏的部分支持，以模拟上述东非土地利用实践导致的灭绝情景。在这个研究工具和仪器的提案中，我寻求资金用于在莱基皮亚的自然降雨梯度沿线建立另外两套草食动物暴露区。因为草食动物的影响取决于降雨，任何关于草食动物灭绝对植物的影响的结论都将局限于与第一次封地相似的降雨量地区。因此，额外的封闭将使我们能够明确地解决降雨在驱动植物种群中的作用，从而允许在草食动物灭绝、土地利用和气候变化的不同情景下产生可靠的预测。这些经历将构成我在UBC的研究项目的基础，我期望在我的职业生涯中培养许多加拿大研究生和本科生。

Although we sometimes possess detailed knowledge about the causes of extinction, a dearth of information exists regarding its consequences for ecological systems. My research group and I work to understand how extinctions of large herbivores affect plant populations in African savannas. Our study sites in Laikipia, Kenya comprise an ideal system in which to study the ramifications of such extinctions. Laikipia consists of a 10,000 square km mosaic of private properties, where each property is associated with one of three scenarios reflecting the progressive, size-biased extinction typical of vertebrate communities: 1) elephant (~3000 kg) + impala (~70 kg) + dik-dik (~5 kg); 2) impala + dik-dik; or 3) dik-dik only. Worldwide, the impacts of herbivory often depend on abiotic factors, and high spatial variation in rainfall throughout East Africa obfuscates the drivers of plant population dynamics. Thus, the first step toward addressing these issues is to experimentally disentangle the relative roles of large herbivores, rainfall, and their interactions in shaping plant populations. This funding request is being submitted simultaneously with an NSERC Discovery Grant proposal. In my Discovery proposal, I seek partial support for a single set of electrified fences to simulate the aforementioned extinction scenarios stemming from land-use practices in East Africa. In this Research Tools and Instruments proposal, I seek funding for the construction of two additional sets of herbivore exclosures to be established along a natural gradient of rainfall in Laikipia. Because impacts of herbivory depend on rainfall, any conclusions about the consequences of herbivore extinction for plants would be restricted to areas receiving similar amounts of rainfall to the first set of exclosures. Thus, additional exclosures would allow us to explicitly address the role of rainfall in driving plant populations, and thus permit the generation of robust predictions under different scenarios of herbivore extinction, land use, and climate change. These exclosures will comprise the foundation upon which my research program at UBC will be built, where I anticipate training many Canadian graduate and undergraduate students throughout my professional career.