Collaborative Research: RAPID: Does a Range Shifting Species Alter Ecosystem Function?

以植物为食的生物在通过生态系统转移能量和营养物质方面发挥着重要作用，这是生态系统为社会提供的许多服务的基础，如渔业、清洁饮用水和碳储存。然而，生态系统中生物的特性和丰度正在发生变化，因为气候温暖的物种进入了以前较冷的地区，这些地区受到气候变化的不成比例的影响。了解这些物种运动如何改变生态系统过程是预测和管理气候变化对生态系统及其服务的影响的重要一步。本研究调查了一种新的水生昆虫物种在高海拔湿地的建立和随后的种群激增如何影响所有生态系统核心过程的时间和规模，即植物材料的消耗，支持植物和动物生长的营养物质的循环，捕食者的猎物的可用性，以及淡水栖息地与周围陆地环境之间的联系。除了科学进步之外，这项研究还通过儿童科学营推进幼儿教育，在野外科学考察期间为公众提供机会，并通过让历史上代表性不足的群体的本科生参与实地生态研究来培养下一代科学家。本研究验证了一个新的假设，即具有不同于常驻物种的生活史特征的范围转移物种的优势地位将改变生态系统过程的物候和规模，改变食物网能量转移，并导致生态系统状态转移。具体而言，本研究调查了最近范围转移的地虱（nemotalius hostilis）丰度的大量增加对生态系统的影响，该物种具有新颖的生活史特征，幼虫发育发生在秋季和冬季，而不是像停留物种那样在夏季。该研究将生物生物量的实地测量与营养循环和碎屑处理的分析相结合，以1)量化范围转移和常驻地虱种群规模以及向蝾螈捕食者种群的能量转移；2)实验测试迁地蝇和常驻地蝇对碎屑资源的密度依赖性竞争；3)利用已建立的模型和30年的球虱和蝾螈丰度数据集来估计与范围转移和常驻球虱相关的过去、当代和未来的生态系统过程结果，包括碎屑分解、养分释放和对陆地生态系统的补贴。这种研究相互关联的生态系统隔间的综合方法产生了具有一般应用的强大的机制理解。此外，通过将关键的顶部捕食者纳入研究，我们将对自上而下的控制如何影响范围转移的生态系统结果有新的认识。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Organisms that feed on plants play important roles in moving energy and nutrients though ecosystems, which underlies many services that ecosystems provide to societies such as fisheries, clean drinking water, and carbon storage. However, the identity and abundance of organisms in ecosystems is changing as warm-climate species move into previously cooler regions that are disproportionately impacted by climate change. Understanding how these species movements alter ecosystem processes is an important step in anticipating and managing the impacts of climate change on ecosystems and their services. This research investigates how the establishment and subsequent population boom of a novel aquatic insect species into high elevation wetlands influences the timing and magnitude of processes central to all ecosystems, namely the consumption of plant material, the cycling of nutrients that support plant and animal growth, the availability of prey for predators, and the connections between freshwater habitats and the surrounding terrestrial environment. In addition to scientific advancement, this research advances early childhood education via childrens’ science camps, provides opportunities for public outreach during science tours at a field station, and trains the next generation of scientists by engaging undergraduate students from historically underrepresented groups in field-based ecological research.This research tests the novel hypothesis that the dominance of a range-shifting species with life history characteristics that differ from resident species will shift the phenology and magnitude of ecosystem processes, altering food-web energy transfer, and resulting in ecosystem state-shifts. Specifically, this research investigates the ecosystem impact of a large increase in the abundance of a recent range-shifting caddisfly (Nemotaulius hostilis) with novel life history trait of larval development occurring in the fall and winter, rather than summer like resident species. The research combines field measurements of organism biomass with assays of nutrient cycling and detritus processing to 1) quantify range-shifting and resident caddisfly population size and energy transfer to salamander predator populations; 2) experimentally test density-dependent competition for detritus resources between range-shifting and resident caddisflies; 3) leverage established models and a 30-year dataset on caddisfly and salamander abundance to estimate the past, contemporary, and future ecosystem-process-outcomes associated with range-shifting and resident caddisflies including detritus decomposition, nutrient release, and subsidies to the terrestrial ecosystem. This combined approach investigating interlinked ecosystem compartments generates a strong mechanistic understanding with general application. Moreover, by integrating the keystone top-predator into the research, we will develop new understanding of how top-down control influences the ecosystem outcomes of range shifts.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.