Collaborative Research: Consequences of habitat heterogeneity and seed dormancy for adaptation at the margins of a native plant population

该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。这个项目的主要目标是了解环境和遗传因素如何影响植物物种范围的局部扩展。尽管近年来已经开发了许多模型来解决这个问题，但很少有经验来测试开发的理论。 这项研究结合了田间实验和建模，以了解植物的范围扩张可能受到人口边缘适应，人口边界的环境变化，以及休眠种子的传播超出这些边界的影响。已知遗传背景的种子将连续两年移植到多个地点，这些地点跨越加州本地一年生植物的当地种群边界。这条边界沿着蜿蜒的草原，具有很高的本地植物多样性和非蜿蜒的草原为主的入侵，非本地物种之间的过渡。与此同时，这些研究人员将开发新的数学模型，以阐明扩散，栖息地变异和适应如何影响当地的范围扩大。这些模型将使用来自田间实验的数据进行参数化，以估计平均存活率和繁殖率，以及这些生命率在地点、年份和基因型之间的变化。我们的综合方法将推进概念和经验的理解如何随着时间的推移扩散，休眠和适应形状的植物分布。该项目的更广泛影响包括保护，培训高级学生和公共教育。 研究范围扩展的机制对于理解入侵植物如何适应它们扩展到新的栖息地以及预测植物物种在快速环境变化下改变其地理分布的条件非常重要。这两种情况都与在不寻常的基质上发现的植物群落特别相关，如蛇纹石土壤。这些生境是一个特殊的保护问题，因为它们的许多本土植物物种是稀有和独特的，因为它们的植物群落受到入侵物种的威胁。该项目将支持和培训来自环境生物学代表性不足群体的大学生和博士后研究员，并将包括面向当地加州公立学校1-7年级学生的科学推广和课程开发。

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). The principal objective of this project is to understand how environmental and genetic factors affect local expansion of plant species' ranges. Although in recent years many models have been developed to address this issue, little has been done empirically to test developed theories. This study combines field experiments and modeling to understand how range expansion in plants may be influenced by adaptation at population margins, by changes in environmental variability across population boundaries, and by dispersal of dormant seeds beyond those boundaries. Seeds of known genetic backgrounds will be transplanted in two successive years into multiple sites spanning the local population boundary of an annual plant native to California. This boundary occurs along a transition between serpentine grassland harboring high native plant diversity and a non-serpentine grassland dominated by invasive, non-native species. Concurrently, these researchers will develop new mathematical models to elucidate how dispersal, habitat variability and adaptation influence local range expansion. The models will be parameterized using data from the field experiments to estimate average survival and reproduction, as well as variation in those vital rates among sites, years and genotypes. Our integrative approach will advance conceptual and empirical understanding of how dispersal, dormancy and adaptation shape plant distributions over time. Broader impacts of this project include conservation, training advanced students, and public education. Studying mechanisms of range expansion is important for understanding how invasive plants adapt as they expand into new habitats and for predicting conditions under which plant species shift their geographic distributions in response to rapid environmental change. Both contexts are especially relevant for plant communities found on unusual substrates, like serpentine soils. Such habitats are a special conservation concern since many of their native plant species are rare and unique, and because their plant communities are threatened by invasive species. The project will support and train university students and post-doctoral fellows from under-represented groups in environmental biology, and will include science-based outreach to, and curriculum development for, local California public school students in grades 1-7.