Collaborative Research: Consequences of Climate-Induced Range Shifts on Multiple Ecosystem Functions

自然生态系统的健康运作取决于共存于其中的各种物种的相互作用。不同但密切相关的物种沿着环境梯度（例如，从干到湿）相互替换。在某些情况下，新物种的功能相似，但在其他情况下，物种的替换对生态系统以及为人类提供的商品和服务产生重大影响。在地球上，物种分布正在随着气候变化而变化，但人们对这种变化将如何影响生态系统知之甚少。在过去的25年里，一项对生活在科罗拉多州落基山脉高海拔池塘里的动物的持续研究表明，物种正在向更高的海拔转移。在同一海拔，随着水的变化，动物们也会迁移到不同类型的池塘（永久的或临时的）。这个新项目的目标是确定这种变化如何影响生态系统功能。本科生的培养是该项目的关键组成部分，本科生将参与研究的各个方面。一个跨机构的研究实验将为他们开发，在那里他们可以共同研究物种范围从北卡罗来纳州转移到缅因州的影响。还将培养一名研究生和一名博士后。最后，该团队将继续在每个家庭机构以及科罗拉多州的落基山生物实验室进行公众宣传，大部分研究将在那里进行。该项目将测试主要腐食动物（caddisfly幼虫）沿环境梯度的范围变化如何影响多个生态系统过程，包括碎屑能量向腐食动物次生产物的转移、藻类吸收的碎屑结合营养物质的释放、藻类对食草动物自下而上的影响以及生态系统代谢。研究人员将使用模型、实验和来自整个池塘的比较数据来研究：1)从碎屑处理速率和对棕色（碎屑）和绿色（藻类）营养路径的级联效应来看，沿着永久梯度和海拔梯度的物种替换在多大程度上是功能性替换；2)在海拔范围内跨越永久梯度的物种转移的相互作用效应，以及与海拔范围转移相关的相互作用效应。3)生态系统过程的变化与群落重排如何扩大到自然池塘。影响将从三个方面进行评估：1)动物食用的死亡植物部分的营养和能量的数量（营养），2)消耗的多少被释放回环境并刺激藻类的生长，藻类也可以被食用，以及3)物种的新组合如何影响池塘的整体生产力。

The healthy functioning of natural ecosystems depends on the interactive roles of the various species that coexist in them. Different but closely related species replace each other along environmental gradients (e.g., from dry to wet). In some cases the new species function similarly, but in others species replacements have major impacts on the ecosystem and the goods and services provided to humans. Around the planet, species distributions are shifting in response to a changing climate, yet little is known about how the shifts will affect ecosystems. One continuous study over the past 25 years of the animals that live in high elevation ponds in the Rocky Mountains of Colorado shows that species are shifting to higher elevations. And at the same elevation animals are moving to different types of ponds (permanent vs. temporary) as the water regime varies. The goal of this new project is to determine how such shifts impact ecosystem function. Training of undergraduate students is a key component of the project and undergraduates will be involved with all aspects of the research. A cross-institutional research experiment will be developed for them, where they can work together to study the impacts of species range shifts from North Carolina to Maine. One graduate student and a postdoctoral associate will also be trained. Finally, the team will continue public outreach at each home institution, as well as at the Rocky Mountain Biological Laboratory in Colorado where most of the research will be conducted. This project will test how range shifts along environmental gradients in the dominant group of detritivores (caddisfly larvae) will affect multiple ecosystem processes, including the transfer of detrital energy to detritivore secondary production, release of detritus-bound nutrients for algal uptake, bottom-up effects of algae on herbivores, and ecosystem metabolism. Researchers will use models, experiments, and comparative data from whole ponds to investigate the degree to which 1) species replacements along permanence and elevational gradients are functional replacements in terms of detritus processing rates and cascading effects on brown (detrital) and green (algal) trophic paths, 2) the interactive effects of species shifts across the permanence gradient within an elevation and those associated with range shifts across elevations, and 3) how changes in ecosystem processes with community rearrangements scale up to natural ponds. Impacts will be assessed on three components: 1) the amounts of nutrients and energy from dead plant parts that are eaten by animals (detritivory), 2) how much of the consumption is released back into the environment and stimulates the growth of algae, which can then also be eaten, and 3) how new combinations of species affect the overall productivity of the ponds.