LTER: Multi-decadal responses of prairie, savanna, and forest ecosystems to interacting environmental changes: insights from experiments, observations, and models

人类活动正在改变地球的生态系统，造成大气中二氧化碳(CO2)浓度、磷和氮等限制性营养物质的供应以及火灾等干扰速度的前所未有的组合。与此同时，人类正在增加物种灭绝和包括害虫和病原体在内的入侵物种的传播。雪松溪长期生态研究计划的研究人员正在使用来自草原、稀树草原和森林的长期模型和数据，以了解和预测这些由人类驱动的相互作用的环境变化将如何改变地球？S生态系统以及生态系统提供支持人类福祉的服务的能力。这项工作建立在CDR标志的基础上，将长期实验和观察的数据结合在一起，探索资源(养分、大气二氧化碳)、环境的非生物方面(温度、降水)、生物多样性和干扰(火、土地利用变化)的变化对地方到全球尺度上相互关联的生态过程的交互影响。除了这一主要研究目标外，CDR项目还将继续通过指导本科生研究人员并为他们提供独立研究和专业发展机会，在科学、技术、工程和数学(STEM)领域培养一支多元化的、具有全球竞争力的劳动力队伍。CDR还将继续通过K-12教育计划、公民科学活动、会员和志愿者计划、公共旅游、成人教育以及艺术和人文伙伴关系，增加公众的科学素养和公众对STEM的参与。这些活动每年涉及数以千计的参观者和参与者，包括明尼苏达州的教师、邻居、公职人员和其他公众。CDR研究将继续对多种环境变化驱动因素的生态影响进行数十年的研究，包括世界上运行时间最长的生物多样性和二氧化碳升高实验，以及世界上运行时间最长的一些关于营养丰富和火灾频率的研究。新的CDR研究计划将建立在过去洞察力的基础上，并寻求更普遍的理解和预测能力。例如，一项新的森林生物多样性实验将建立在过去CDR生物多样性研究的基础上，以理清生物多样性多个方面(功能、系统发育和物种)的作用，并使用树木来测试生物多样性理论的普遍性。第二，在长期生物多样性实验和稀树大草原中复制的新实验将确定干旱、养分、变暖和生物多样性对生态系统过程和稳定性的交互影响。第三，新的计划将开发和测试预测生态系统如何从长期的氮素富集化中恢复的模型。第四，新的实验将测试关于消费者如何相互作用，如野牛和火灾干扰，以重组和改变草原、稀树草原和森林生态系统功能的假设。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Human activities are altering the earth's ecosystems and creating unprecedented combinations of carbon dioxide (CO2) concentrations in the atmosphere, supplies of limiting nutrients like phosphorus and nitrogen, and rates of disturbances such as fire. At the same time, humans are increasing species extinctions and the spread of invasive species, including pests, and pathogens. Researchers at the Cedar Creek Long Term Ecological Research Program (CDR) are using long-term models and data from grasslands, savannas, and forests to understand and forecast how these interacting human-driven environmental changes will alter the earth?s ecosystems and the ability of ecosystems to provide the services that support human well-being. This work builds on the CDR hallmark of combining data from long-term experiments and observations to explore the interactive effects of changes in resources (nutrients, atmospheric carbon dioxide), abiotic aspects of the environment (temperature, precipitation), biodiversity, and disturbance (fire, land use change) on linked ecological processes at local to global scales. In addition to this primary research goal, the CDR program will continue to develop a diverse, globally competitive workforce in Science, Technology, Engineering, and Math (STEM) by mentoring undergraduate researchers and providing them with independent research and professional development opportunities. CDR also will continue to increase public scientific literacy and public engagement with STEM through K-12 education programs, citizen science activities, membership and volunteer programs, public tours, adult education, as well as arts and humanities partnerships. These activities reach thousands of visitors and participants each year, including teachers, neighbors, public officials, and other members of the public in Minnesota.CDR research will continue its multi-decadal studies of the ecological impacts of multiple environmental change drivers, including the longest-running biodiversity and elevated CO2 experiments in the world, and some of the world's longest-running studies of nutrient enrichment and fire frequency. New CDR research initiatives will build from past insights and seek more general understanding and predictive ability. For example, a new forest biodiversity experiment will build on past CDR biodiversity research to disentangle the roles of multiple facets of biodiversity (functional, phylogenetic, and species) and use trees to test the generality of biodiversity theory. Second, new experiments replicated in the long-term biodiversity experiment and savanna will determine the interactive effects of drought, nutrients, warming, and biodiversity on ecosystem processes and stability. Third, new initiatives will develop and test models that predict how ecosystems recover from chronic nitrogen enrichment. Fourth, new experiments will test hypotheses about the how consumers such as bison and fire disturbance interact to restructure and alter the functioning of grassland, savanna, and forest ecosystems.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.