Long-Term Ecological Research (LTER) at Hubbard Brook Experimental Forest (HBR-LTER)

凭借其半个世纪的生态学研究历史，哈伯德·布鲁克(HBR)遗址已演变为LTER模型，收集了森林流域生态系统中独特且极其宝贵的长期生物地球化学循环记录。HBR的首要目标是增加对美国东北部森林景观的生态模式和过程的了解，特别是在应对干扰方面。研究了三种类型的扰动：1)空气污染，2)灾难性事件(例如，砍伐)和3)非灾难性事件(例如，土壤冻结事件、冰暴和昆虫暴发)。生物地球化学研究建立在40年来实验流域元素通量和植被动态记录的基础上，重点是建立定量的营养循环。长期测量、实验和过程研究是在各种尺度上进行的，从小块土地到整个流域和森林。长期实验包括一项全流域钙肥研究，旨在抵消酸沉积造成的土壤钙流失，并跟踪整个流域的钙通量和循环，特别是对目前正在下降的糖枫种群的影响。这些实验和正在进行的过程研究将结合新的举措，审查复合干扰对生态系统结构和功能、元素化学计量和滞后的影响，所有这些都是在生态状态因素的景观水平变化的背景下进行的。新的研究包括：1)幼林和成熟林施氮、磷和钙的小区水平施肥；2)对不同营养水平的山毛榉树皮病害进行深入而广泛的研究；3)详细研究与糖枫衰退、森林营养和生产力有关的氮和碳动态。更广泛的影响。HBR研究与空气污染和大气沉积对生态系统过程的影响等重要社会问题密切相关。《哈佛商业评论》的主要科学家积极参与有关空气污染、酸沉积及其生态后果的区域和国家宣传活动。随着《哈佛商业评论》产生了具有新闻价值的科学发现和生产受欢迎的产品，这一范围得到了扩大。HBR是在高影响力期刊、有影响力的合成产品和论文/学位论文发表方面生产率最高的LTER网站之一。新的概念框架旨在指导未来的HBR，并可能影响其他LTER研究。该网站的研究已经培养了两代以上的杰出生态系统科学家，并将继续培养大量的本科生、研究生和博士后。HBR正在积极增加多样性和妇女对科学的参与，从学生层面到教职员工层面。其他外展活动包括校园LTER计划、公共生态旅游和创新的科学链接功能。

With its half-century history of ecological research, the Hubbard Brook (HBR) site has evolved into a model LTER gathering unique and extremely valuable records of long-term biogeochemical cycling in forested watershed ecosystems. The overarching goal of HBR is to increase understanding of the ecological patterns and processes that characterize forested landscapes in the northeastern USA, particularly in response to disturbances. Three types of disturbances are examined: 1) air pollution, 2) catastrophic events (e.g., clear-cutting) and 3) non-catastrophic events (e.g., soil freezing events, ice storms and insect outbreaks). Biogeochemical studies build on a 40-year record of element fluxes and vegetation dynamics in experimental watersheds, focused on construction of quantitative nutrient cycles. Long-term measurements, experiments and process studies are conducted at a variety of scales, ranging from small plots to entire watersheds and forests. Long-term experiments include a whole-watershed calcium fertilization study designed to offset soil Ca losses due to acidic deposition and to track calcium fluxes and cycling throughout the watershed, with particular emphasis on effects on currently declining sugar maple populations. Such experiments and ongoing process studies are to be coupled with new initiatives examining the effects of compounded disturbances on ecosystem structure and function, elemental stoichiometry and hystereses, all in the context of landscape-level variation in ecological state factors. New studies include 1) plot-level fertilization of young and mature forest with nitrogen, phosphorus and calcium, 2) intensive and extensive study of beech bark disease across multiple trophic levels, and 3) detailed study of nitrogen and carbon dynamics in relation to sugar maple decline, forest nutrition and productivity. Broader Impacts. HBR research is crucially linked with the important societal issues of air pollution and the effects of atmospheric deposition on ecosystem processes. Key HBR scientists are active in regional and national outreach regarding air pollution, acid deposition and their ecological consequences. This outreach is expanded with HBR's generation of newsworthy scientific findings and the production of popularly accessible products. HBR is among the most productive LTER sites in terms of publications in high impact journals, influential synthesis products and theses/dissertations. The new conceptual framework is intended to guide HBR in the future and is likely to influence other LTER research as well. Research at this site has trained more than two generations of prominent ecosystem scientists and will continue this with the training of a high number of new undergraduates, graduate students and postdocs. HBR is actively increasing diversity and the participation of women in science, from the student level to the faculty level. Additional outreach includes the Schoolyard LTER program, public ecological tours and the innovative Science Links feature.