US-South Africa Dissertation Enhancement: A Demographic Analysis of Life History Variation and Seed Dispersal in the Ant-Dispersed Proteaceae

9819840Stanton本学位论文增强补助金资助美国研究生Caroline Christian女士，她在加州大学戴维斯分校人口生物学中心的Maureen L.Stanton教授的指导下工作。克里斯蒂安女士将对南非蚂蚁分散的Proteaceae的生活史、变异和种子传播进行人口统计学分析。许多动物是种子传播的媒介，但由于栖息地的改变，许多种子传播者正在失去，导致许多植物物种的减少。蚂蚁种子散布是世界上许多易起火灌木丛的主要种子传播方式。这种散布方法在南非的开普弗洛里斯特地区尤其重要，该地区拥有数量异常多的稀有蚂蚁散布物种。通过取代本地蚂蚁传播者，非本土阿根廷蚂蚁正在重塑该地区蚂蚁种子传播互惠关系，但对植物种群的长期影响知之甚少。克里斯蒂安女士将研究在蚂蚁散布的Proteaceae中发现的两种生活史形成的两种潜在的选择性力量：蚂蚁传播种子和火灾频率。她将研究两个有着相似生活史但具有不同生殖特征的Proteaceae物种的种群动态。通过受控田间实验，克里斯蒂安女士将研究种子传播的组成部分如何影响种子休眠、种子存活率和幼苗的建立。来自田间试验和人口统计数据的数据将被用来开发一个矩阵模拟模型，以预测哪些种类的物种对种子传播方法的变化最敏感。这一预测模型具有重要的保护应用价值。南非博物馆的著名非洲蚂蚁分类学家哈米什·罗伯逊博士将为克里斯蒂安女士提供这个项目的指导。研究结果将为植物种群动态研究提供重要的新知识。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。

9819840StantonThis dissertation enhancement grant supports a US graduate student, Ms. Caroline Christian, working under the guidance of Professor Maureen L. Stanton, of the Center for Population Biology at the University of California, Davis. Ms. Christian will conduct a demographic analysis of the life history variation and seed dispersal in the ant-dispersed Proteaceae of South Africa. Many animals serve as mediators for seed dispersal, but due to habitat alterations many seed dispersers are being lost, resulting in a decline in many plant species. Ant seed dispersal is the major seed dispersal method in many fire-prone shrublands worldwide. This dispersal method is especially important in the Cape Floristic region of South Africa, which contains an unusually high number of rare ant-dispersed species. Through its displacement of native ant dispersers, the non-indigenous Argentine ant is reshaping ant seed-dispersal mutualisms in this region, but little is known about the long-term consequences on plant populations. Ms. Christian will examine the two potential selective forces that have shaped the two life histories found in the ant-dispersed Proteaceae: seed dispersal by ants, and fire frequency. She will examine the population dynamics of two Proteaceae species which share similar life histories, but have different reproductive characteristics. Through controlled field experiments, Ms. Christian will examine how the components of seed dispersal influence seed dormancy, seed survivorship, and seedling establishment. Data from the field experiments and from demographic plots will be used to develop a matrix simulation model to predict which types of species are most sensitive to alterations in seed dispersal methods. This predictive model can have significant conservation applications. Dr. Hamish Robertson, a leading African ant taxonomist at the South African Museum, will provide guidance on this project to Ms. Christian. The results will provide important new knowledge about plant population dynamics. This project will also support an international research experience very early in the career of an outstanding graduate student.