Tree-ring width, and tree-ring stable carbon isotope data from SW Alaska

These data include tree-ring chronologies and stable carbon isotope data for locations in southwestern Alaska that were used in the study Decoupling of temperature and growth of white spruce at western treeline, Alaska is unrelated to intrinsic water stress. The ring-width index (RWI) chronologies were produced by first removing age-related declines in growth by fitting a modified negative exponential curve, or a zero-slope curve if there were no age-related declines, to each ring-width series and then by averaging the individual indices together using a Tukey bi-weight robust mean (Cook and Kairiukstis 1990) using the dplR package (Bunn 2008) in R (R Core Team 2018). RWI is a dimentionless index used for tree ring chronologies. Carbon stable isotope chronologies were produced for a 30-50 year period from each side. Wood was sub-sampled to alpha cellulose using the modified Brendel et al. (2005) method (Gaudinski et al. 2011) and analyzed at the University of Arizona, Environmental Isot..., , # Tree-ring width, and tree-ring stable carbon isotope data from SW Alaska

Dataset DOI: [10.5061/dryad.9w0vt4bsm](10.5061/dryad.9w0vt4bsm)

## Description of the data and file structure

The study sites comprise a subset of a larger network of monitoring plots on the northern Alaska Peninsula, on and adjacent to National Park Service lands (Csank et al. 2016; Sherriff et al. 2017). At each site, we preferentially cored a minimum of 20 mature, large diameter canopy trees at a distance of at least 10 m from one another. At forest sites we sampled trees >20 cm DBH and >10 m in height. At woodland sites, where trees were smaller, we sampled trees >8 cm DBH. Additional details regarding field methods can be found in previously published studies from these sites (Csank et al. 2016; and Sherriff et al. 2017). 

Cores were collected at 30-50 cm above the root crown and crossdated using standard dendrochronological techniques (Stokes and Smiley 1996). Tree-ring widths for each core were counted...,