OPUS: CRS, Soil Biogeochemical Responses to Interacting Global Change Drivers and Feedbacks to the Climate System

长期生态数据集的合成对于提供新的科学见解和进展是重要的。该项目的目的是对近20年来从几个长期全球变化实验中收集的数据进行研究和综合。总体目标是了解土壤对三个对美国东北部生态系统具有重要意义的全球变化(气候变暖、大气氮沉积和非本土植物入侵)的响应。土壤是陆地生物圈中碳(作为有机质)的最大储存库，这些全球变化加速或抑制土壤有机质退化的程度将影响碳和养分的循环过程和对气候系统的反馈。这项研究的结果和产品将提供对土壤变暖、土壤氮素增加和植物入侵如何相互作用影响森林土壤生物和化学过程的综合理解。该OPUS项目的目的是对哈佛森林长期生态研究站点18年来四个长期全球变化实验收集的数据进行核心研究综合，目的是了解多种全球变化驱动因素如何单独和联合作用影响土壤微生物和生物地球化学参数，重点是真菌群落和土壤有机质动态。正在进行的实验持续了14-32年，代表了全球同类实验中运行时间最长的一些操作。这些地点气候相同，土壤、植被和土地利用历史相似，使用相同的土壤变暖和氮肥技术。已经进行了一套协调的生物地球化学和微生物测量。这种数据综合方法提供了一个独特的机会，可以了解随着时间的推移，土壤温度上升、土壤氮素丰富和生物入侵如何单独或联合影响土壤生物地球化学、植物-土壤相互作用和微生物群落动态。虽然已经针对单个实验进行了几次合成，但还没有协调一致的努力来整合和合成跨实验的数据。综合计划有两个关键组成部分：(1)测试土壤碳对同时变暖和氮素增加的反应机制；(2)真菌群落对全球变化的反应及其与土壤碳储量的联系的交叉研究综合。数据集包括：1)土壤非生物参数(温度、水分、pH、容重、质地)的长期记录；2)生物地球化学测量(土壤呼吸、无机N、N矿化、土壤总C和N、根生物量、菌根定植)；3)微生物生物量、活性、多样性、群落组成和功能容量。该项目将为博士后研究人员提供培训，研究结果将被纳入新汉普郡大学的课堂教学。该奖项反映了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。

Synthesis of long-term ecological datasets is important for providing new scientific insights and advances. The aim of this project is to conduct a research synthesis of data collected over nearly two decades from several long-term global change experiments. The overarching goal is to understand the soil responses to three global changes of significance for ecosystems in the northeastern United States (climate warming, atmospheric nitrogen deposition, and invasion by non-native plants). Soils are the largest repository of carbon (as organic matter) in the terrestrial biosphere, and the degree to which these global changes will accelerate or suppress soil organic matter decay will influence carbon and nutrient cycling processes and feedbacks to the climate system. The results and products of this research will provide a synthetic understanding of how soil warming, soil nitrogen enrichment, and plant invasion interact to influence biological and chemical processes in forest soils.The aim of this OPUS project is to conduct a core research synthesis of data collected over 18 years from four long-term global change experiments at the Harvard Forest Long-term Ecological Research site with the goal to understand how multiple global change drivers act individually and in combination to influence soil microbial and biogeochemical parameters, with an emphasis on fungal community and soil organic matter dynamics. The ongoing experiments span 14-32 years in duration and represent some of the longest running experimental manipulations of their type globally. These sites have the same climate and similar soils, vegetation, and land-use histories and use identical soil warming and nitrogen fertilization techniques. A coordinated set of biogeochemical and microbial measurements have been made. This data synthesis approach offers a unique opportunity to understand how increasing soil temperatures, soil nitrogen enrichment, and biotic invasion individually or in combination affect soil biogeochemistry, plant-soil interactions, and microbial community dynamics over time. While several syntheses have been done for individual experiments, there has been no coordinated effort to integrate and synthesize data across experiments. The synthesis plan has two key components: (1) testing a mechanism for the soil carbon response to simultaneous warming and nitrogen enrichment, and (2) a cross-study synthesis of fungal community responses to global change and linkages to soil carbon storage. Data sets to be used in this synthesis include long-term records of 1) soil abiotic parameters (temperature, moisture, pH, bulk density, texture); 2) biogeochemical measurements (soil respiration, inorganic N, N mineralization, total soil C and N, root biomass, mycorrhizal colonization); and 3) microbial biomass, activity, diversity, community composition, and functional capacity. The project will provide training for postdoctoral researchers and study results will be incorporated into classes taught at the University of New Hampshire.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.