Refer to Table 2 in the Photographs section for post-treatment data by species and size class.
Data collection methodology for pre- and post-release (Tables 1 & 2):
Randomly distributed fixed-radius circular plots, 1/250th acre in size. Plot locations were different during both measurement periods. Tally all commercial tree species <5" dbh and >12" in height within plot radius in 2 size classes. Plot is considered stocked if it meets above noted stocking criteria
Basal Area: At each plot in the post-thinning survey a 10-factor prism was used to measure basal area of trees => 5" DBH. There should be no difference between the pre and post-thinning basal area as no trees larger than 5" DBH were cut during the thinning.
The goal on these sites was to try and maintain the diversity present on the site by favoring rare species (primarily birch (paper and yellow), oak, elm, basswood, and pine, and disfavoring aspen, which generally dominated most areas. We marked crop trees and then a chainsaw crew followed up by cutting anything that was in crown competition about 6’ around each marked stem. Anecdotally it really helped maintain species that were otherwise being overtaken by aspen.
It’s labor intensive, but instead of a stand that would ultimately end up 85% aspen and 15% “other”, we probably bumped it something more like 60% aspen and 40% “other”. In 45 more years we can go in and remove the ~65 year old aspen and paper birch while leaving everything else and probably end up with 20% aspen and 80% “other”. We don’t have a lot of nice northern hardwood stands and so maintaining or enhancing them where we can is important.