This dataset contain the secondary growth rates of a selection of 360 stems of the three most common species in the Scotty Creek ForestGEO plot. Growth was measured using microcores obtained by Katherine Dearborn in 2019 using a Trephor punch microcorer.

Sampling design: 
We had previously used principal components analysis to summarize patterns in abiotic variables at the 20 x 20 m grid cell scale throughout the Scotty Creek ForestGEO plot (Dearborn et al. 2021. Journal of Ecology). The first axis was representative of gradients in soil moisture content and frost table depth, while the second was representative of patterns in organic layer thickness. To select stems for microcore sampling, we first identified all 20 × 20 m grid cells that contained at least ten stems of the focal species (Picea mariana, Larix laricina, and Betula spp.) and divided them into categories that were greater than or less than the median values of a) basal area of the focal species, b) principal component 1, and c) principal component 2. We then assigned grid cells into categories based on every combination of these classes for a total of eight categories per species. Next, we randomly selected three grid cells per category for a total of 24 grid cells per species. Finally, we randomly selected five stems from each of these 24 grid cells (using each stem’s unique tree tag number), resulting in a total of 120 stems sampled per species (360 stems total across all three species). We obtained two to three cores from each stem (at 90 degree angles from one another) to capture within-stem variation in growth (~720 cores in total).

Labwork:
We used a high-resolution scanner and a camera mounted on a high-magnification dissection scope to photograph cores, then measured the ring widths of each core to create a ring width series for each core. Finally, we combined series from the same stem together to obtain an average measure of growth for each stem.

Column names are as follows:
tag = the tree tag number associated with the sampled stem
stem = the stem number of the sampled stem, if applicable (for multistemmed individuals only; a stem number 0 indicates that the main stem was sampled or that there were no multistems, 1 corresponds with multistem tag A, 2 with multistem tag B, etc.)
x = x-coordinate of the stem in m from origin (see scotty_plot_layout.pdf for more info)
y = y-coordinate of the stem in m from origin (see scotty_plot_layout.pdf for more info)
DBH1 = diameter at breast height of the stem in mm at the time of the initial census (2012-2014) obtained by using a dbh tape.
DBH2 = the diameter at breast height of the stem in mm at the time of the recensus (2018) obtained by adding up the ring widths between the two censuses (to obtain the increase in radius), multiplying by two (to obtain the increase in diameter), then adding the increase in diameter to the initial diameter measurement.