DISSERTATION RESEARCH: Biotic interactions and the geographic range limit of Clarkia xantiana across a complex environmental gradient

论文研究：复杂环境梯度下的生物相互作用和 Clarkia xantiana 的地理范围限制

基本信息

批准号：
1701072
负责人：
David Moeller
金额：
$ 1.99万
依托单位：
University of Minnesota-Twin Cities
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2017
资助国家：
美国
起止时间：
2017-05-15 至 2019-04-30
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1701072&HistoricalAwards=false
关键词：
DISSERTATION RESEARCH Biotic interactions geographic

项目摘要

It is a longstanding question why some species are found across vast portions of the earth (e.g., dandelions), and some species only occur in small patches of habitat. Similarly, the fact that some species are expanding their ranges rapidly (e.g., invasive species) while many are not remains difficult to explain. Figuring out what enables, or prevents, plants from growing in certain areas has far reaching consequences for management of invasive species, continued productivity of crops in variable environments, and protection of threatened organisms. This project uses a Californian plant species, (Clarkia xantiana), restricted to a small area of Southern California to explore the environmental factors limiting species distributions. Studies often only consider climatic factors, such as temperature and precipitation, as drivers of these distributions. But researchers are increasingly realizing the role microorganisms play in affecting plant growth and distribution. This project will characterize soil microbial communities within and outside C. xantiana's native range, and use a novel field experiment to test how microbes and rainfall may interact to limit C. xantiana's range. The researchers will also conduct a series of educational field trips with a local middle school to teach students about hypothesis testing, scientific experiments, and the natural history of Southern California. This project uses next generation sequencing and a manipulative field experiment to explore interactions between soil microbial communities, precipitation, and plant traits, and how these factors influence the geographic distribution of Clarkia xantiana ssp. xantiana in the foothills of the Southern Sierra Nevada. Multivariate statistical analyses will be used to examine patterns of community shifts across geographic space, focusing on those microbial taxa differentiating sites within and outside C. xantiana's distributional limit. An in situ soil microbial transplant experiment, paired with a rainfall manipulation treatment, will quantify the main and interactive effects of these factors on fitness outside the range. PVC growth cores installed in the ground at sites outside the range edge will be used to manipulate local soil microbial environments surrounding individual xantiana plants via inoculation with microbial communities from inside the range. This is paired with a rainfall manipulation treatment in a split-plot design, where half of the plots will receive 50% rainfall addition. The effects of site, rainfall treatment, inoculum, and all two-way interactions on components of lifetime fitness and phenology will be analyzed using ANOVA.

这是一个长期以来的问题，为什么在地球大部分地区（例如蒲公英）中发现了某些物种，而某些物种仅出现在小小的栖息地中。同样，某些物种正在迅速扩展其范围（例如，入侵物种），而许多物种并不难解释。找出在某些地区的启用或阻止植物在某些地区生长的原因对侵入性物种的管理，可变环境中农作物的持续生产力以及对受威胁生物的保护产生的影响。该项目使用加利福尼亚植物（Clarkia Xantiana），仅限于南加州的一小部分，以探索限制物种分布的环境因素。研究通常仅将气候因素（例如温度和降水）视为这些分布的驱动因素。但是，研究人员越来越多地意识到微生物在影响植物生长和分布中的作用。该项目将表征C. Xantiana的本地范围内外的土壤微生物群落，并使用新颖的现场实验来测试微生物和降雨如何相互作用以限制C. Xantiana的范围。研究人员还将与当地的中学进行一系列教育实地考察，以向学生传授假设检验，科学实验和南加州的自然历史。该项目使用下一代测序和操纵性场实验来探索土壤微生物群落，降水和植物特征之间的相互作用，以及这些因素如何影响Clarkia Xantiana SSP的地理分布。 Xantiana在内华达山脉南部的山麓地区。多元统计分析将用于检查跨地理空间的社区转变模式，重点介绍了C. Xantiana的分布限制内外的微生物分类分类地点。原位土壤微生物移植实验与降雨操纵处理配对，将量化这些因素对范围内适应性的主要和互动效果。范围边缘外部位于地面上安装的PVC生长核心将用于操纵Xantiana植物周围的局部土壤微生物环境，通过接种从范围内的微生物群落接种。这是在分开图设计中与降雨操纵处理搭配的，其中一半的地块将增加50％的降雨量。现场，降雨处理，接种物以及所有双向相互作用对终生健身和物候组成部分的影响，将使用ANOVA分析。