Community assembly and ecosystem processes in the light of evolutionary history: the formation and function of plant communities

一个世纪以来，对群落生态学家来说，了解决定物种共存和由此产生的多样性模式的基本过程一直是至关重要的。尽管有丰富的文献，但问题仍然存在：物种的相似性和差异在产生我们观察到的生态群落和过程中有多重要？我们目前的理解是，一个物种进入一个群落的能力取决于两个因素：资源利用的重叠程度，其中生态位划分促进了稳定的共存，以及物种之间适应度差异的大小。我将利用植物物种之间的进化关系和性状差异来理解共存的机制，从而了解群落多样性模式。我将采用观察、实验和理论方法来测试在确定不同植物物种共存的过程中，空间和时间上偶然过程如何与物种特征相互作用。我的研究将包括四个目标。首先将评估生态位差异是如何通过植物物种之间的进化关系来表现的。第二项将是在Jokers Hill对植物多样性进行大型实验操作，以了解进化史在生物生产和维持传粉媒介多样性等生态系统过程中有多重要。第三是评估之前实验中的多样性如何预测引进外来物种的成功。最后的目标将是监测alvar群落（一种濒临灭绝的生境类型）并评价物种关系在多样性、功能和入侵模式方面的作用。确定进化史和特征差异的作用是理解群落是如何组成的以及它们为何以这种方式运作的关键。这样的理解可以让科学家评估物种保护的价值，以及如何最大限度地发挥恢复群落的功能。我提出的研究将是第一个评估进化史如何影响当前共存和生态系统功能的研究。

The quest to understand the fundamental processes determining species coexistence and resulting patterns of diversity has been of central importance for community ecologists for a century. In spite of a rich literature, the question remains: How important are species' similarities and differences in generating the ecological communities and processes we observe? Our current understanding is that the ability of a species to enter a community depends on two things: the degree of overlap in resource use, where niche partitioning promotes stable coexistence, and the magnitude of fitness differences among species. I will use evolutionary relationships and trait differences among plant species to understand mechanisms of coexistence, and therefore community diversity patterns. I will employ observational, experimental and theoretical approaches to test how spatially and temporally contingent processes interact with species traits in determining the coexistence of different plant species. My research will be comprised of four objectives. First will be to assess how niche differences are represented by evolutionary relationships among plant species. Second will be a large experimental manipulation of plant diversity at Jokers Hill to see how much evolutionary history matters in ecosystem processes such as biomass production and maintaining pollinator diversity. Third will be to assess how diversity in the previous experiment predicts the success of introduced exotic species. The final objective will be to monitor alvar communities (an endangered habitat type) and to evaluate the role of species relationships for patterns of diversity, function and invasion. Determining the role of evolutionary history and trait differences is key to understanding how communities are put together and why they function the way they do. Such an understanding can allow scientists to evaluate species conservation value and how to maximize the function of restored communities. My proposed research will be the first to evaluate how evolutionary history impacts current coexistence and ecosystem function.