LTREB: The Population and Community Dynamics of Desert Winter Annuals

0212782 Venable这个LTEB的建议是在美国亚利桑那州图森市附近的沙漠实验室的索诺兰沙漠站点的永久地块上，扩展对沙漠冬季一年生植物种群和群落动态的连续记录。它将澄清和扩大人口统计变异和协变及其在人口和社区过程中的作用的理解。本野外站将在10 - 19年前建立的长期样地上，在灌木冠下和开阔地，连续监测荒漠一年生植物的萌发、存活和繁殖数据。延迟发芽和年间种子携带被认为是重要的沙漠一年生植物的持久性，因此土壤种子储量的大小将被监测，并确定什么分数发芽，在每年的灌木下和开放的每一个物种。种子将从标准化的土壤样品中分离出来，并进行生存力测试。这项研究的结果将与天气数据一起分析，以确定气候变化如何决定这些一年生植物物种的种群变化。研究人员将构建这一沙漠年系统的种群和群落模型，这些模型将用于探索土壤种子库在面对环境变化时缓冲种群的作用。沙漠一年生植物作为模式生物，在我们理解生物如何适应多变和不可预测的环境方面发挥了重要作用。它们也被用来解释在可变环境中的非平衡群落动态。然而，它们的动力学并不为人所知的经验，特别是种子的行为。该项目将为评估这些想法提供最好的长期可用数据。在该系统的进化生态学、种群生态学和群落生态学方面已经进行了大量的理论和实验工作。这种理论和实验工作与长期观察的结合被证明是产生植物生态学新见解和综合的有力途径。这项研究将通过在一所主要研究型大学的学术环境中进行，进一步实现研究与教育相结合的目标。研究生和本科生将参与促进实践培训和研究经验的能力，补充正式课程。博士，硕士和本科生荣誉项目将作为本研究的一部分或分支。REU支持将寻求相关的本科项目。在这项研究的第一阶段，参与该项目的本科生和研究生中有一半以上是妇女，将努力在拟议的研究中纳入更高比例的妇女。PI将通过与校园内的少数民族访问计划合作，奋进将代表性不足的种族和文化群体纳入这项研究。

0212782VenableThis LTREB proposal is to extend the continuous record of population and community dynamicsof desert winter annual plants on permanent plots at a Sonoran Desert site at the DesertLaboratory near Tucson, AZ, USA. It will clarify and extend the understanding of demographicvariation and covariation and its role in population and community processes. Data ongermination, survival and reproduction of desert annual plants will be continuously monitored onlong-term plots established from 10 to 19 years ago at locations both under shrub canopies and inthe open at this field station. Delayed germination and between year seed carry over are thoughtto be important for the persistence of desert annuals, so the magnitude of the soil seed reserveswill be monitored and determine what fraction germinate in each year for each species undershrubs and in the open. Seeds will be separated from standardized soil samples and tested forviability. The results of this research will be analyzed together with weather data to determinehow climatic variation determines population variation for these annual plant species. Theinvestigators will then construct population and community models of this desert annual system.These models will be used to explore the role of soil seed banks in buffering populations in theface of environmental variation. They will also be used to investigate how life historydifferences among species promote their coexistence and species diversity.Desert annual plants have played an important role as model organisms in the development of ourunderstanding of how organisms adapt to variable and unpredictable environments. They havealso been used to exemplify ideas about non-equilibrium community dynamics in variableenvironments. Yet their dynamics are not well known empirically, especially the behavior ofseeds. This project will provide the best available long-term data for evaluating these ideas.There has been considerable theoretical and experimental work carried out on the evolutionaryecology, population ecology and community ecology of this system. Such combinations oftheoretical and experimental work with long-term observations are proving to be a powerfulapproach to yield new insights and syntheses in plant ecology.This research will further the goal of combining research and education by virtue of occurring inthe academic environment of a major research university. Graduate and undergraduate studentswill be involved in capacities that fosters hands-on training and research experience thatcomplements formal coursework. Ph.D., Masters, and undergraduate honors projects will befacilitated as part of or offshoots of this research. REU support will be sought for relatedundergraduate projects. In the first phase of this research more than half of the undergraduateand graduate participants in this project were women and an attempt will be made to include ahigh percentage of women in the proposed research. The PI will endeavor to includeunderrepresented ethnic and cultural groups in this research by working with minority accessprograms on campus.