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).