US-Kenya Dissertation Enhancement: Aloe Secundiflora Shrubs as Facilitators in Semi-Arid Kenyan Rangelands, and Their Potential Use in Restoration

0218254 Stanton&Amp；Kin这篇论文资助了美国研究生伊丽莎白·金女士，她在加州大学戴维斯分校种群生物学中心的Maureen Stanton教授的指导下，在肯尼亚进行了一项研究，以评估多汁灌木库拉索芦荟对退化的半干旱稀树草原上多年生草本植物Cichrus ciliaris的促进作用。不同植物物种成员之间的促进作用可以影响相互作用物种的种群动态和植物群落的结构。但促进者和受益物种之间的关系并不是一成不变的，根据物种的生活史阶段，在某些时间和某些条件下，甚至可能变得消极。在一系列不同的环境条件下，金女士将测量移植的芦荟灌木对受益草的每个生活史阶段的影响，以便预测移植的芦荟灌木的存在对种群水平的影响。她将回答以下问题。在一系列可能的环境条件下，相互作用向量如何变化？互动向量如何根据受益人的生活历史阶段而变化？植物群落中其他物种的间接影响如何影响局部受益物种的相互作用？当在人口模型中使用特定阶段的健康测量时，促进者的存在如何影响受益者的预测人口增长率？这些结果将被用来评估使用这些移植的多肉灌木作为促进过度放牧的干燥稀树草原牧草恢复的一种手段的潜在影响。肯尼亚国家博物馆的Joshua Muasya博士和Emily Wabuyele女士将就这一项目向King女士提供指导。这项研究的结果有望增加目前关于促进植物与受益物种相互作用的知识。它还将为参与遏制环境退化和改善人类福利的资源管理者和政策制定者提供宝贵的信息，这些问题是肯尼亚和世界其他地方干旱地区面临的问题。该项目还将支持一名优秀研究生在职业生涯早期的一次国际研究经历。国际科学与工程办公室和环境生物学部门共同支持这一奖项。

0218254Stanton & KingThis dissertation enhancement grant supports a US graduate student, Ms. Elizabeth King, working under the direction of Professor Maureen Stanton, in the Center for Population Biology at the University of California- Davis, to conduct a study in Kenya to evaluate the facilitative effect of the succulent shrub Aloe secundiflora on a perennial grass species, Cenchrus ciliaris, in degraded, semi-arid savannas.Facilitative interactions between members of different plant species can impact the population dynamics of the interacting species and the structure of plant communities. But the relationship between a facilitator and a beneficiary species is not constant and, depending on the life history stage of the species, can even become negative at certain times and under certain conditions. Under an array of different environmental conditions, Ms. King will measure the effect of transplanted aloe shrubs on each life history stage of the beneficiary grass in order to project the population-level consequences of the presence of the transplanted aloe shrubs. She will address the following questions. How does the interaction vector vary under a spectrum of possible environmental conditions? How does the interaction vector vary depending on the life history stage of the beneficiary? How do indirect effects of additional species in the plant community impact the interaction vector for a focal beneficiary species? When stage-specific fitness measurements are used in demographic models, how does the presence of a facilitator affect the projected population growth rate of the beneficiary? The results will be used to evaluate the potential impact of the use of these transplanted succulent shrubs as a means to enhance the recovery of grasses in overgrazed dry savannas. Dr. Joshua Muasya and Ms. Emily Wabuyele at the National Museums of Kenya will provide guidance on this project to Ms. King.The results of this study are expected to add to the current knowledge on the interactions of facilitator plants with a beneficiary species. It will also contribute valuable information to resource managers and policy makers involved in curtailing environmental degradation and improving human welfare--problems that face arid areas in Kenya and elsewhere in the world. This project will also support an international research experience very early in the career of an outstanding graduate student.The Office of International Science and Engineering and the Division of Environmental Biology jointly support this award.