NOAA/WDS Paleoclimatology - Touchan - Kef Laagab - PIHA - ITRDB TUN011

The first large-scale network of tree-ring chronologies from the western Mediterranean (WM; 32°N–43°N, 10°W–17°E) is described and analyzed to identify the seasonal climatic signal in indices of annual ring width. Correlation and rotated empirical orthogonal function analyses are applied to 85 tree-ring series and corresponding gridded climate data to assess the climate signal embedded in the network. Chronologies range in length from 80 to 1129 years. Monthly correlations and partial correlations show overall positive associations for Pinus halepensis (PIHA) and Cedrus atlantica (CDAT) with winter (December–February) and spring (March–May) precipitation across this network. In both seasons, the precipitation correlation with PIHA is stronger, while CDAT chronologies tend to be longer. A combination of positive correlations between growth and winter–summer precipitation and negative partial correlations with growing season temperatures suggests that chronologies in at least part of the network reflect soil moisture and the integrated effects of precipitation and evapotranspiration signal. The range of climate response observed across this network reflects a combination of both species and geographic influences. Western Moroccan chronologies have the strongest association with the North Atlantic Oscillation.

本研究对地中海西部（WM；北纬32°–43°，西经10°–东经17°）首个大型树轮年表网络进行了描述与分析，旨在识别年尺度年轮宽度指数中的季节性气候信号。研究采用85条树轮序列及对应格点气候数据，通过相关分析与旋转经验正交函数(rotated empirical orthogonal function)分析，评估该网络中蕴含的气候信号。所有年表的长度介于80至1129年之间。月相关分析与偏相关分析结果表明，地中海松（Pinus halepensis, PIHA）与大西洋雪松（Cedrus atlantica, CDAT）的生长指标，与该研究区域冬季（12月—次年2月）、春季（3月—5月）的降水整体呈正相关关系。在这两个季节中，地中海松序列与降水的相关性更强，而大西洋雪松年表的存续年限普遍更长。生长与冬夏降水呈正相关，同时与生长季温度呈负偏相关，这表明该网络至少部分区域的年表记录了土壤湿度状况，以及降水与蒸散(evapotranspiration)的综合气候信号。本研究观测到的跨网络气候响应差异，是物种特性与地理区位双重影响共同作用的结果。摩洛哥西部的树轮年表与北大西洋涛动(North Atlantic Oscillation)的相关性最强。