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

9819840Stanton这项论文强化资助资助了一名美国研究生Caroline Christian女士，她在加州大学戴维斯分校人口生物学中心Maureen L. Stanton教授的指导下工作。克里斯蒂安女士将对南非反分散的变形科植物的生活史变异和种子传播进行人口统计学分析。许多动物作为种子传播的媒介，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上许多易发火灾灌木林的主要种子传播方式。这种扩散方法在南非开普植物区尤其重要，该地区含有数量异常高的稀有抗分散物种。通过取代本地蚂蚁传播者，非本地阿根廷蚂蚁正在重塑该地区蚂蚁种子传播的相互关系，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量，这两种力量塑造了在蚂蚁分散的变形科中发现的两种生命史：蚂蚁的种子传播和火灾频率。她将研究两种具有相似生活史但具有不同繁殖特征的变形科物种的种群动态。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。来自田间试验和人口统计图的数据将用于开发一个矩阵模拟模型，以预测哪种类型的物种对种子传播方法的变化最敏感。该预测模型具有重要的保护应用价值。南非博物馆（South African Museum）著名的非洲蚂蚁分类学家哈米什·罗伯逊（Hamish Robertson）博士将在这个项目上为克里斯蒂安提供指导。研究结果将为植物种群动态提供重要的新知识。该项目还将支持优秀研究生在职业生涯的早期获得国际研究经验。

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.