Tree ring width data for trees adjacent to the BBC collapse scar

This data set contains ring width data for trees adjacent to the BBC collapse scar. We used dendrochronology to link paleoecological data with modern observations of the response of this system to fire. Tree ring analysis provides a record of the response of the black spruce trees to changing climate and ongoing thermokarst, allowing for speculation about the response of this landscape to future climate change. We harvested twenty-one fire-killed tree cross-sections from the margin of the collapse and in the surrounding burn in the growing season of 2004. We measured ring width (sliding stage, Velmex Inc., Bloomfield, NY, USA, resolution: 0.001mm) for two radial transects of the tree cross-sections. To remove the age-related variation in growth rate, we crossdated trees with Cofecha and standardized ring-widths with the program ARSTAN (Richard Holmes, Laboratory of Tree Ring Research, University of Arizona). We recorded the presence of compression-wood for each tree ring, an indicator of leaning which is interpreted to be related to frost-heaving and permafrost collapse (Camill and Clark, 1998). This data set includes temperature and precipitation data from a composite of climate data from the University Experiment Station (1906-1947) and Fairbanks International Airport (1948-2000) (Wilmking et al., 2004).

本数据集包含紧邻BBC塌陷瘢痕（BBC collapse scar）的树木的年轮宽度数据。本研究采用树木年代学（dendrochronology）方法，将古生态数据与该生态系统对火灾响应的现代观测结果相结合。年轮分析可记录黑云杉（black spruce）应对气候变化与持续热喀斯特（thermokarst）的过程，借此可推演该景观对未来气候变化的响应。2004年生长季，我们从塌陷区域边缘及周边过火区内采集了21株被火烧死的树木的横切片。我们对树木横切片的两条径向样带开展年轮宽度测量，测量采用滑动台（sliding stage），设备来自美国纽约州布卢姆菲尔德市Velmex公司（Velmex Inc., Bloomfield, NY, USA），分辨率达0.001毫米。为消除生长速率随树龄产生的变异，我们使用Cofecha软件完成树木交叉定年，并通过ARSTAN程序（由亚利桑那大学树木年轮研究实验室Richard Holmes开发）对年轮宽度数据进行标准化处理。我们记录了每一个年轮中的应力木（compression-wood）存在情况——应力木是树木倾斜的指示特征，被认为与冻胀（frost-heaving）及永久冻土塌陷相关（Camill与Clark，1998）。本数据集还包含整合后的气候数据：1906-1947年数据取自大学实验站，1948-2000年数据取自费尔班克斯国际机场，相关气候数据集来自Wilmking等人2004年的研究（Wilmking et al., 2004）。