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，植物正在向山坡上移动，进入更凉爽的气候。这一运动的一个未被充分研究的结果是，由于与向上迁徙的物种有更多竞争，不能再往山上移动的高山物种可能会变得更加稀有。这种激烈的竞争会不会强大到足以导致物种灭绝？这项研究将提供这一情景的为数不多的实验测试之一，使用美国科罗拉多州落基山脉南部的高山植物群落。该项目通过将竞争实验与数学模型相结合来扩展过去的工作，以预测未来的人口增长，并将结果推广到其他生态系统。这项研究将为不同温度和降水模式下高山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、娱乐和恢复具有重要意义的物种。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推广计划，为本科生和公众提供研究机会。研究人员使用利基模型为一项实验提供了信息，该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。结果表明，低海拔植物群落比居留高山群落对局部高山物种性能的影响更大。研究人员正在将自然种群的人口统计数据与现场竞争操作相结合，以将整体投影模型参数化。这些模型旨在长期预测实验条件下局部物种的种群增长，以确定它们在因气温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。研究人员将收集有关重点物种和竞争群落的植物特征和环境数据，以使一个新的基于特征的模型参数化，该模型旨在根据物种特征的差异预测竞争相互作用的结果。通过根据新测量的性状-环境关系预测竞争环境，该项目将产生对各种物理和竞争环境中植物表现的先验预测。

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.