Douglas-fir ring width data for reconstructing past periods of western spruce budworm outbreak

The western spruce budworm (Choristoneura occidentalis; \"WSB\") is one of the most widely distributed native defoliators of coniferous forests in North America, where it plays an important role in shaping ecosystem function. Here we provide tree-ring data used to reconstruct periods of past WSB outbreak at 12 sites across central to northern Colorado over the past 300 years. , Ring-width data for reconstructing periods of WSB outbreak were collected from Douglas fir in the 1990s, but unpublished. Sample sites were selected based on the availability of large, old Douglas fir and the absence of evidence of recent (i.e., since c. 1940) fire or logging to minimize the potential effects of other disturbances on radial growth. At each site, tree-ring data were collected by preferentially sampling at least 20 large Douglas fir using an increment borer. Cores were transferred back to the lab, where they were dried, mounted, and sanded to a fine polish, following standard dendrochronological methods. Ring widths were then measured to a 0.01 mm precision using a Velmex UniSlide digital encoded traversing table paired with a standard light microscope. To ensure accurate dating, ring-width series were visually cross-dated using the maker year approach and statistically verified using the dplR package in R., , # Douglas-fir ring width data for reconstructing past periods of western spruce budworm outbreak [https://doi.org/10.5061/dryad.bnzs7h4n3](https://doi.org/10.5061/dryad.bnzs7h4n3) ## Description of the data and file structure Tree ring data for reconstructing past periods of western spruce budworm outbreak across Colorado. ### Files and variables This dataset provides site metadata and annual tree-ring measurements for 15 sites across Colorado where Douglas-fir were sampled to reconstruct periods of past outbreak. Metadata information for all sites are provided in the* Host-Metadata.csv* file. Tree-ring data for each site are provided as individual *.rwl* files. In each of these data files, the data are stored in Tucson decadal format where the first 10 values following the decade are the 10 annual measurements for the 10 years of that decade. The code 999 or -9999 indicate the end of the record code. Measurements are in units of 0.01 mm (end code 999) or 0.001 mm (end code -9999)....,西部云杉卷叶蛾（Choristoneura occidentalis，简称WSB）是北美本土分布最广泛的针叶林食叶害虫之一，在塑造生态系统功能方面发挥着重要作用。本研究提供了用于重建过去300年间科罗拉多州中部至北部12个站点西部云杉卷叶蛾暴发周期的树木年轮数据。 用于重建西部云杉卷叶蛾暴发周期的树轮宽度数据于20世纪90年代从花旗松上采集，但尚未发表。采样站点的选择依据为：存在大型老龄花旗松，且无近70年来（即约1940年以来）火灾或采伐的记录，以尽可能降低其他干扰对径向生长的潜在影响。在每个站点，通过生长锥优先采集至少20株大型花旗松的样本以获取树木年轮数据。将钻取的木芯带回实验室，按照标准树木年代学方法进行干燥、固定并打磨至精细抛光状态。随后使用搭配标准光学显微镜的Velmex UniSlide数字编码移动台，以0.01毫米的精度测量年轮宽度。为确保定年准确，年轮宽度序列采用标记年法进行目视交叉定年，并通过R语言的dplR包进行统计验证。 # 用于重建西部云杉卷叶蛾既往暴发周期的花旗松树轮宽度数据 [https://doi.org/10.5061/dryad.bnzs7h4n3](https://doi.org/10.5061/dryad.bnzs7h4n3) ## 数据与文件结构说明 用于重建科罗拉多州全域西部云杉卷叶蛾既往暴发周期的树木年轮数据。 ### 文件与变量 本数据集包含科罗拉多州15个站点的站点元数据与年树木年轮测量数据，这些站点均通过采集花旗松样本以重建既往西部云杉卷叶蛾暴发周期。所有站点的元数据均存储于*Host-Metadata.csv*文件中。各站点的树木年轮数据以单独的*.rwl*文件形式提供。在所有此类数据文件中，数据均以图森十年格式存储：年代标识后的前10个数值对应该年代10年的年度测量值。代码999或-9999代表记录结束标识。测量值单位分别为0.01毫米（结束代码为999时）与0.001毫米（结束代码为-9999时）……