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

9819840StantonThis论文增强补助金支持美国研究生，卡罗琳基督教女士，在教授莫林L。加州大学戴维斯分校人口生物学中心的斯坦顿说。 Christian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。 许多动物充当种子传播的媒介，但由于栖息地的改变，许多种子传播者正在消失，导致许多植物物种的减少。 蚂蚁种子传播是世界范围内许多易发生火灾的灌木林的主要种子传播方式。 这种传播方法在南非的开普植物区系地区尤为重要，该地区含有数量异常多的稀有蚂蚁传播物种。 通过取代本地蚂蚁传播者，非土著阿根廷蚂蚁正在重塑该地区的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。 克里斯蒂安将研究两种潜在的选择力，它们塑造了蚂蚁分散的Proteaceae中发现的两种生活史：蚂蚁的种子传播和火灾频率。 她将研究两种Proteaceae物种的种群动态，这两种物种具有相似的生活史，但具有不同的生殖特征。 通过受控的田间实验，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，种子存活和幼苗建立。 从田间试验和人口统计图的数据将被用来开发一个矩阵模拟模型，以预测哪些类型的物种是最敏感的种子传播方法的改变。 这种预测模型可以有显着的保护应用。 哈米什·罗伯逊博士是南非博物馆的一位著名的非洲蚂蚁分类学家，他将为克里斯蒂安女士提供这个项目的指导。这些结果将为植物种群动态提供重要的新知识。 该项目还将在优秀研究生的职业生涯早期提供国际研究经验。

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.