LTREB Renewal: Emergent landscape patterns in stream ecosystem processes resulting from groundwater/surface water interactions

这项研究的重点是热带溪流的水化学如何受到地表水和地下水输入的影响，以及这些输入反过来又如何受到厄尔尼诺南方涛动等气候变化的影响。这是一项长期研究的延续，该研究汇编了中美洲唯一连续的长期（20年）河流化学记录。在与厄尔尼诺事件相关的长期干旱期之后，缓冲不良的低地溪流在长达8个月的时间里酸度增加了100倍。这些延长的酸化事件似乎是正常季节（即干季/湿季）趋势的放大。该项目调查了导致这些事件的机制，以及这种酸化如何影响溪流的生态。中美洲的低地溪流支持着各种水生群落，并将大量碳从高产的陆地生态系统输送到大气和海洋。据预测，中美洲的气候将导致旱季降雨量减少。这种气候变化可能会对新热带河流的化学成分产生重大的有害影响。为了在更全球化的背景下更好地理解这些研究成果，该项目在中美洲的长期数据集正在与整个热带地区（例如亚马逊河、刚果河、湄公河和恒河）的其他数据集联系起来。此外，该项目的成果将在“生命之水”项目中传播，该项目包括在当地社区开展外展活动，以及一个配有河流保护和水质/水量问题教学工具的国际无障碍网页。

This study focuses on how the water chemistry of tropical streams is influenced by surface and groundwater inputs and how these inputs are, in turn, affected by climatic variations such as the El Nino Southern Oscillation. This is a continuation of a long-term study that has compiled the only continuous long-term (20 yrs) record of stream chemistry in Central America. Following long dry periods associated with El Nino events, poorly-buffered lowland streams exhibit 100-fold increases in acidity for up to eight months. These prolonged acidification events appear to be an amplification of normal seasonal (i.e. dry season/wet season) trends. This project investigates the mechanisms causing these events and how this acidification affects the ecology of the streams.Lowland streams in Central America support diverse aquatic communities and transport large amounts of carbon from highly productive terrestrial ecosystems to the atmosphere and ocean. The climate in Central America is predicted to have decreased dry-season rainfall. This climatic shift will likely have major deleterious effects on the chemistry of neo-tropical streams. To better understand these research findings in a more global context, the long-term data set from this project in Central America is being linked to other data sets throughout the tropics (e.g., Amazon, Congo, Mekong and Ganges Rivers). In addition, the results of this project will be disseminated in the Water for Life/Agua para la Vida program, which includes outreach activities in local communities and an internationally accessible web page equipped with teaching tools on river conservation and water quality/quantity issues.