DISSERTATION RESEARCH: King of the hill? How competitive interactions affect biogeographical pattern and species responses to environmental variability.

随着气温的升高，植物正沿着山坡向更凉爽的气候迁移。这种迁移的一个未被充分研究的结果是，由于与向上迁移的物种竞争加剧，无法向山上迁移的高山物种可能会变得更加稀少。这种激烈的竞争是否足以导致物种灭绝？这项研究将利用美国科罗拉多州落基山脉南部的高山植物群落，为这一情景提供为数不多的实验测试之一。该项目通过将竞争实验与数学模型相结合来预测未来的人口增长，并将结果推广到其他生态系统，从而扩展了过去的工作。该研究将为变温变降水模式下的高寒和其他生态系统的管理提供新的见解，特别是对野生动物管理、娱乐和恢复中重要的物种。此外，该项目将利用落基山生物实验室的科学节和儿童自然营的外展项目，为本科生和公众提供研究机会。研究人员利用生态位模型进行了一项实验，将高山物种移植到预计会侵蚀上坡的低海拔植物群落中。结果表明，低海拔植物群落对高山焦点物种的影响大于高山常驻群落。研究人员将自然种群的人口统计数据与实地竞争操作相结合，以参数化积分投影模型。这些模型的目的是在实验条件下对焦点物种种群增长进行长期预测，以确定它们在因温度升高而改变的竞争环境中的生存能力。这个项目将把这些结果推广到更广泛的系统和物种。研究人员将收集焦点物种和竞争群落的植物性状和环境数据，以参数化一个新的基于性状的模型，旨在预测物种性状差异的竞争相互作用结果。通过在新测量的性状-环境关系上预测竞争环境，该项目将在各种物理和竞争环境中产生植物性能的先验预测。

Plants are moving up mountainsides into cooler climates as temperatures have increased. An understudied consequence of this movement is that alpine species, which cannot move further up mountains, may become rarer because of more competition with the upward migrating species. Could this intensified competition be strong enough to cause species extinctions? This research will provide one of the few experimental tests of this scenario, using alpine plant communities of the southern Rocky Mountains, CO, USA. This project expands upon past work by coupling competition experiments with mathematical models to predict population growth into the future and to generalize the results to other ecosystems. This research will provide new insights for the management of alpine and other ecosystems under variable temperature and precipitation patterns, specifically for species important in wildlife management, recreation, and restoration. In addition, this project will provide research opportunities for undergraduate students and the public by utilizing the Rocky Mountain Biological Laboratory's Science Festival and Kids Nature Camp outreach programs.The researchers have used niche models to inform an experiment that transplanted alpine species into the low elevation plant communities expected to encroach upslope. Results suggest that focal alpine species performance is reduced more by low elevation plant communities than by resident alpine communities. The researchers are combining demographic data from natural populations with field manipulations of competition to parameterize integral projection models. These models are aimed at long-term predictions of focal species population growth under experimental conditions to determine their viability in a competitive environment altered by increased temperatures. This project will generalize these results to a wider set of systems and species. The researchers will collect plant trait and environmental data on focal species and competing communities to parameterize a new trait-based model aimed at predicting competitive interaction outcomes from differences in species traits. By predicating the competitive environment on newly measured trait-environment relationships, this project will produce a priori predictions of plant performance in various physical and competitive environments.