Dissertation Research: Tree-grass Interactions in a Kenyan Savanna: the Effects of Wild and Domestic Herbivores

许多栖息地是树木和草的混合物。这些地区包括大草原、热带稀树草原和林地。这些社区的草木平衡经常发生变化，对当地生物多样性和人类都产生了重要影响（丛林入侵、牧场生产）。然而，人们对这些变化背后的机制知之甚少，部分原因是树木和草对彼此既有积极的影响，也有消极的影响。例如，树木和草竞争水和光，但也可以改善土壤条件，保护彼此免受食草动物的侵害。在肯尼亚的金合欢稀树草原上进行的大规模长期实验将研究树与草之间的相互作用以及稀树草原生态是如何受到以下因素的影响的：(1)野生和家养食草动物，(2)树木大小，(3)树木密度。这项研究的目标之一是让当地利益相关者了解他们土地管理做法的后果。在世界上的许多地方，包括肯尼亚的研究区，野生动物与家畜在混合使用的牧场上共存。了解野生和家养食草动物对树-草相互作用的影响，对于成功地管理这些牧场，实现生产和保护目标至关重要。该项目将使区域土地管理人员随时了解其调查结果。将与利益攸关方举行几次非正式讲习班，讨论他们对该地区历史变化的看法，传播研究成果，并讨论其对管理的影响。

Many habitats are a mixture of trees and grasses. These include prairies, savannas, and woodlands. These communities often shift in their balance of grasses and trees, with important consequences for both native biodiversity and humans (bush encroachment, rangeland production). However, the mechanisms underlying these changes are poorly understood, in part because trees and grasses can have both positive and negative effects on each other. For example, trees and grasses compete for water and light, but also can improve soil conditions and protect each other from herbivores. Large-scale, long-term experiments in an acacia savanna in Kenya will examine how tree-grass interactions, and savanna ecology in general, are effected by a) wild and domestic herbivores, b) tree size, and c) tree density. One of the goals of this research is to inform local stakeholders of the consequences of their land management practices. In many parts of the world, including the study area in Kenya, wildlife coexists with domestic cattle on mixed-use rangeland. An understanding of the effects of wild and domestic herbivores on tree-grass interactions is central to successful management of these rangelands for both production and conservation objectives. This project will keep regional land managers informed of its findings. Several informal workshops will be held with stakeholders to discuss their perceptions of historical changes in the area, to disseminate research results, and to discuss their management implications.