Effects of Climate Change in the Colorado Alpine: Ecosystem Response to Altered Snowpack and Rainfall Regimes

过去40年在尼沃特岭测量的气候数据表明，这个温带高山地区正在发生方向性变化。更冷、更湿的条件与植物群落组成的变化、土壤pH值的降低和对植被氮限制控制的改变有关。虽然未来可能出现许多气候情景，但由于反照率和蒸散量的增加，高山降水的增加可能会使降温趋势继续下去。因此，这项新的研究将强调积雪和降水对高山生态系统过程和模式的影响。项目组将确定和量化控制高山生态系统对积雪和降水响应的机制，并根据这些知识开发预测模型。研究重点有四个方面：(1)影响地球化学收支的流域物理和生物过程；(2)植物和土壤微生物过程，强调微生物对养分分配、库和通量、光合作用和净初级生产量的控制；(3)利用地理信息系统和遥感技术，对涉及动植物种群和群落的景观进行分层分析；(4)近几个世纪和几千年来古生态对雪况变化的响应。所有的研究领域都使用面向过程的模型，提供分析和预测能力。将这些模型与地理信息系统技术相结合，将提供空间显式表示，并提供一种将相关生物物理过程扩展到区域水平的机制。

Climatological data measured over the past 40 years at Niwot Ridge show that this temperate alpine site is undergoing directional change. Cooler, wetter conditions correlate with shifts in Plant community composition, reduced soil pH and modification of controls on nitrogen limitation to vegetation. While a number of future climatic scenarios are possible, enhanced precipitation in the alpine may continue the cooling trend due to increased albedo and evapotranspiration. This new research will therefore emphasize the influence of snowpack and precipitation on alpine ecosystem processes and patterns. The project group will identify and quantify mechanisms controlling the alpine ecosystem response to snowpack and precipitation and develop prediction models based on this knowledge. The research has four focal points: (1) watershed-level physical and biological processes affecting geochemical budgets; (2) plant and soil microbial processes, emphasizing organismic controls on nutrient allocation, pools and fluxes, photosynthesis and net primary production; (3) a hierarchical set of landscape analyses involving populations and communities of plants and animals and employing GIS and remote sensing techniques; and (4) paleoecological responses to changed snow conditions during recent centuries and millennia. All research areas use process-oriented models that provide analytical and predictive capabilities. Interfacing these models with GIS technologies will provide spatially explicit representation and provide a mechanism to scale relevant biophysical processes to regional levels.