Tree-Ring Analysis of Long-term Temporal and Spatial Variability of Drought on the Northern Plains of Canada

加州大学洛杉矶分校自然发生的干旱是美国和加拿大大平原农业和资源管理的长期问题。由于来自平原的大多数气候记录长度较短，预测潜在干旱严重程度的努力受到阻碍。拟议的研究将利用树轮分析来提取建立评估潜在严重程度基线所需的长期气候记录。该研究项目将在艾伯塔省、萨斯喀彻温省和马尼托巴省的一些地点从活树和亚化石木材中获得树轮。这些地点与美国现有的地点相结合，将首次形成一个真正全面的平原树木年轮网络。基于年轮宽度和密度的树木年轮年表将至少在过去500年内建立起来。将研究降水量、年轮宽度和密度之间的关系，并开发传递函数，以重建这段时间的区域干旱记录。将对由此产生的记录进行分析，以确定晚材密度作为降水预测因子的相对能力、近期干旱的严重性(相对于较早的干旱)以及北部平原的干旱发生模式和周期性。本研究既有理论研究，也有应用研究。

U. of California, Los Angeles Naturally occurring droughts are a chronic problem for agriculture and resource management in the Great Plains of the U.S. and Canada. Attempts to predict potential drought severity are hampered by the short length of most climatic records from the plains. The research proposed will utilize tree ring analysis to extract long term climatic records needed to establish baselines for assessing potential severity. The research project will obtain tree rings from living trees and subfossil wood at a number of sites in Alberta, Saskatchewan and Manitoba. These sites when combined with existing sites in the U.S. will form a truly comprehensive tree ring network of the plains for the first time. Tree ring chronologies based on ring widths and densities will be constructed for at least the last 500 years. Relations between precipitation, ring widths and density will be examined and transfer functions developed to reconstruct regional records of drought for this period of time. The resulting records will be analyzed to determine the comparative ability of latewood density as a predictor of precipitation, the severity of recent as opposed to older droughts, and drought occurrence patterns and periodicities in the northern plains. The research is both theoretical and applied.