Biogeochemical and Vegetational Responses to an ExperimentalSimulation of Ecosystem Warming

预计下个世纪的气候变化将影响生态系统，但我们缺乏预测这些影响的方向和程度的知识。这项研究将通过现场操作提高我们预测这些影响的能力，在科罗拉多州落基山生物实验室，使用架空散热器增加亚高山草甸内大片地块的向下热通量。热通量将被设置为与2050年最坏气候情景下预测的地表变暖大致相符。这种变暖对土壤湿度和温度、土壤养分库和转化、温室气体通量、植物生产、物种分布和物候的影响将被测量。小气候和养分循环模型，每一个都将用对照样地的数据进行校准，并用暖样地的数据进行验证，这将扩展我们对植被、温室气体通量、土壤养分和土壤小气候之间的反馈机制的认识，并将为将我们的发现推广到其他样地提供基础。这项研究还将确定气候敏感的生态参数，这些参数可能成为全球变暖生态症状在地理上广泛监测的目标。

Climate changes projected for ext century will impact ecosystems, yet the knowledge to foresee the direction and magnitude of these impacts is lacking. This study will improve our ability to predict these impacts by field manipulations, using overhead radiators to increase the downward heat flux on large plots within a subalpine meadow at the Rocky Mountain Biological Laboratory, CO. The heat flux will be set to match approximately the surface warming predicted in worst-case climate scenarios for the year 2050. Effects of this warming on soil moisture and temperature, soil nutrient pools and transformations, greenhouse gas fluxes, and plant production, species distribution, and phenology will be measured. Microclimate and nutrient cycle models, each to be calibrated with data from the control plots and validated with data from the warmed plots, will extend our knowledge of feedback mechanisms linking vegetation, greenhouse gas fluxes, soil nutrients, and soil microclimate, and will provide a basis for generalizing our findings to other sites. The research will also identify climate-sensitive ecological parameters that could be targets for geographically widespread monitoring of ecological symptoms of global warming.