Tree-ring width measurements of Douglas fir from Degerloch from 1916 to 2021

Wood samples from Douglas fir trees were taken using an increment borer. From each tree two opposing increment cores were taken at breast height. The sampled trees stood in an area of ~50x50 meters. Total ring width was measured and digitized. The resulting two radii measurements of each tree were visually synchronized and averaged to form a tree-ring series. Additionally, metadata were collected such as tree height, circumference and provenance (coastal, interior). The tree-ring data were used to investigate the resilience, resistance and recovery of the Douglas fir trees to severe drought events and to perform climate sensitivity analysis. This tree-ring dataset was part of a sampling campaign to assess the growth potential of Douglas fir trees until the year 2100. Annual tree growth variability until 2100 was modeled for Germany (including the river basins draining to Germany) with a spatial resolution of 12x12 km using regional climate projections ensemble.研究人员采用树木生长锥（increment borer）采集花旗松（Douglas fir）的木芯样本：每棵树均在距地面1.3米的胸高位置采集两枚相对的木芯。采样林分分布于约50×50米的区域内。研究人员对总年轮宽度进行测量并完成数字化处理，将每棵树获取的两枚半径测量值进行目视配准后取平均值，以此构建单棵树的年轮序列。此外还采集了树高、树干周长以及种源地（沿海、内陆）等元数据。该年轮数据集被用于探究花旗松对极端干旱事件的抗性、恢复力与灾后恢复能力，并开展气候敏感性分析。该年轮数据集是一项采样研究计划的组成部分，该计划旨在评估花旗松直至2100年的生长潜力。研究团队利用区域气候投影集合（regional climate projections ensemble）数据集，以12×12千米的空间分辨率，对德国全境（含汇入德国的所有流域）内直至2100年的树木年生长变异性进行了模拟建模。