Collaborative Research: LTREB- Long-Term Ecosystem Responses to More Extreme Precipitation Patterns and Warming

气温和降雨极大地影响了草原的结构和功能，使其特别容易受到预计的气候变化的影响。在中原地区，平均气温预计将上升，降雨模式预计将变得更加多变和极端，大降雨事件的频率增加，降雨间干旱延长。这些变化的生态后果很难预测。该LTREB项目通过支持在一个独特的实验设施(降雨控制小区、坡道)中对降雨和温度的长期控制来应对潜在的气候变化的后果。七年来，我们一直在评估重复的、完整的草原地块中降雨模式变化的影响(更大的降雨事件和更长的降雨间干旱，但总降雨量没有变化)。我们的中心假设是，降雨事件时间的变化将显著改变土壤水分的时间模式和深度分布，对植物、群落和生态系统过程产生长期影响。2003年，我们增加了一项变暖处理，以评估更极端的降雨模式(气候变异性增加)和气温上升(气候平均增加)相结合的后果。更极端的降雨模式和更温暖的气温的相互作用预计将是复杂的，但对于预测未来气候情景下草原资源和生态系统服务的可持续性至关重要。该LTREB项目将支持本科生和研究生的培训，向科学界提供新的数据，并向公众宣传全球变化研究的重要性。

Temperature and rainfall greatly influence the structure and function of grasslands, making them particularly vulnerable to projected climate changes. In the Central Plains mean temperatures are expected to increase and rainfall patterns are predicted to become more variable and extreme, with an increased frequency of large rainfall events and extended inter-rainfall droughts. The ecological consequences of these changes are difficult to predict. This LTREB project addresses the consequences of potential climate change by supporting the long-term manipulation of rainfall and temperature in a unique experimental facility (the Rainfall Manipulation Plots, RaMPs). For seven years, we have been assessing the impacts of altered rainfall patterns (larger rain events with longer inter-rainfall droughts, but no change in total precipitation amount) in replicated, intact grassland plots. Our central hypothesis is that changes in the timing of rainfall events will significantly alter temporal patterns and depth distributions of soil moisture, with long-term consequences for plant, community and ecosystem processes. In 2003 we added a warming treatment to assess the consequences of a combination of more extreme rainfall patterns (increased climatic variability) and increased temperatures (increased climatic mean). The interactive effects of more extreme rainfall patterns and warmer temperatures are expected to be complex, but will be critical for predicting the sustainability of grassland resources and ecosystem services under future climate scenarios. This LTREB project will support the training of undergraduate and graduate students, provide new data to the scientific community, and inform the general public on the importance of global change research.