LTREB: Biogeochemical Mechanisms of Response in the Third Decade of Whole-Ecosystem Experimental Manipulations at the Bear Brook Watershed in Maine (BBWM)

这笔拨款将用于支持缅因州的熊溪流域（BBWM），在那里进行了大约20年的关于大气硫和氮沉积对森林影响的研究。研究在两个流域进行，每个流域由一阶流排水。其中一个每两个月由直升机处理一次，以模拟大气中硫和氮的沉积。在过去的20年里，这项研究已经确定并验证了控制森林对空气污染反应的关键因素，也揭示了我们在理解上的主要差距，这些差距对于确定《清洁空气法》及其1990年修正案下当前和潜在的未来法规的成功至关重要。最近的研究还在研究气候如何与其他空气污染物相互作用，从而决定水质和森林健康。这笔拨款将支持该项目进入第三个十年，届时新的生态响应机制正在出现，而这些机制只能通过长期的、多十年的研究来调查。这个项目更广泛的影响包括培养本科生和研究生，他们将成为未来的科学领袖。这项研究提供了模拟空气污染物的化学处理对整个生态系统反应的直接证据，提供了受控实验室研究无法提供的结果。酸沉降问题仍然是森林生态系统健康和水质关注的问题。气候和酸沉积之间也有直接的相互作用，世界上很少有实地研究地点准备研究。这项研究直接解决了今天和未来的这些信息需求。

This grant will support the Bear Brook Watershed in Maine (BBWM) where research has been conducted for approximately 20 years on the effects of atmospheric sulfur and nitrogen deposition on forests. The research is conducted on two watersheds, each drained by a first order stream. One is treated bimonthly by helicopter to simulate atmospheric deposition of sulfur and nitrogen. Over the past 20 years, this research has identified and verified key factors governing forest response to air pollution, and also revealed major gaps in our understanding that are critical to determining the success of current and potential future regulations under the Clean Air Act and its amendments of 1990. Recent research is also studying how climate interacts with other air pollutants to determine water quality and forest health. This grant will support the project into the third decade where new ecological response mechanisms are emerging that can only be investigated by long-term, multi-decadal research. The broader impacts of this project include the training of undergraduate and graduate students who will be the scientific leaders of tomorrow. This research provides direct evidence of whole-ecosystem responses to chemical treatments that simulate air pollutants providing results not possible from controlled laboratory studies. The issue of acid deposition remains a concern for forest ecosystem health and water quality. There are also direct interactions between climate and acid deposition that few field research sites in the world are prepared to study. This research directly addresses those information needs for today and the future.