Environmental Variation, Dormancy, and Rare Plant Persistence in Invaded Habitats

入侵栖息地的环境变化、休眠和稀有植物的持久性

• 批准号: 0236070
• 负责人: Jonathan Levine
• 金额: $ 50.02万
• 依托单位: University of California-Los Angeles
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-01-15 至 2003-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0236070&HistoricalAwards=false
• 关键词: Environmental; Variation; Dormancy; Rare; Plant

Growing concerns over the persistence of threatened and endangered species have rekindled interest in one of the classic problems in ecology: how do rare species persist? Without large populations distributed across heterogeneous environments, rare species are traditionally regarded as susceptible to extinction from environmental variability. By contrast, numerous coexistence models suggest that for species with dormancy, environmental fluctuations may beessential for persistence in competitive communities. Variable germination and dormancy allow species to exploit temporal variation to avoid both unfavorable environments and intense competition. Despite acceptance among community ecologists that environmental fluctuations may favor coexistence via these "storage effect" mechanisms, their implications for understanding how rare plants persist are only beginning to be explored. Better understanding how dormancy, surrounding community dynamics, and environmental variation influence persistence is essential to successfully managing threatened populations. This proposal outlines research to examine how rare annual plants persist in the highly variable, exotic grass dominated habitats of the California Channel Islands. With tenfold annual variation in rainfall, and over 15 rare and endangered annual plants, the island system provides a unique opportunity to examine how germination biology, environmental variation, and surrounding community dynamics influence persistence. The research team brings together a theoretical ecologist specializing in annual plant population models, a field ecologist with experience studying biological invasions in California herbaceous systems, and a conservation practitioner working in the Channel Islands National Park. The intellectual merit of the proposed research is that it will clarify how dormancy, environmental variation and surrounding community dynamics influence the persistence of rare annual plants. This is particularly important considering the increased environmental variation forecasted with climate change, and the continuing invasion of exotic species. The broader implications include the training of postdoctoral, graduate, and undergraduate students to work at the interface of models and experiments, and the generation of data necessary for successfully managing the rare annual plants of the Channel Islands. Through collaborations with the National Park Service and Nature Conservancy, the results of this project will be communicated to the general public and those directly responsible for managing the unique island flora.

人们对受到威胁和濒危物种的持续存在的持续性越来越担心，重新点燃了对生态学的经典问题之一的兴趣：稀有物种如何持续存在？如果没有分布在异质环境中的大种群，传统上，稀有物种被认为容易受到环境变异性的灭绝。相比之下，众多共存模型表明，对于有休眠状态的物种，环境波动可能会使竞争社区的持久性令人愉悦。可变发芽和休眠使物种可以利用时间变化，以避免不利的环境和激烈的竞争。尽管社区生态学家接受了环境波动可以通过这些“存储效应”机制有利于共存，但它们对理解稀有植物持续存在的含义才刚刚开始探索。更好地理解休眠，周围的社区动态和环境变化影响持久性对于成功管理受威胁人口的持久性至关重要。该提案概述了研究，以研究罕见的每年植物如何在加利福尼亚海峡群岛的高度可变的异国草占主导地位的栖息地中持续存在。降雨年度的十倍变化，以及15种稀有和濒危的年度植物，该岛系统提供了一个独特的机会，可以研究发芽生物学，环境变化和周围社区动态如何影响持久性。研究小组汇集了一名专门研究年度植物人群模型的理论生态学家，这是一位野外生态学家，具有研究加利福尼亚草本系统生物学入侵的经验，以及在海峡群岛国家公园工作的保护从业人员。拟议的研究的智力优点在于，它将阐明休眠，环境变化和周围的社区动态如何影响罕见的年植物的持久性。考虑到随着气候变化预测的环境变化的增加以及外来物种的持续入侵，这一点尤其重要。更广泛的含义包括培训博士后，研究生和本科生，以在模型和实验的界面上工作，以及成功管理频道群岛罕见的年度植物所需的数据。通过与国家公园管理局和自然保护协会的合作，该项目的结果将与公众传达，以及直接负责管理独特岛屿植物的人。