PS 30-171 - Community analyses of remnant forests in Shelby Co., TN reveal potential eastern old-growth forest

Abstract: European colonization of eastern North America resulted in widespread destruction of old
growth eastern deciduous forest, negatively impacting native plant and animal biodiversity over
the last several centuries. However, remnant old growth forest may be more common than
previously thought, and urban forested natural areas may also contain old growth forest
elements. While harboring important native eastern forest biodiversity and providing important
ecosystem services, these forests may also be threatened by continued anthropogenic
disturbance, especially if such forests remain “hidden” or uncharacterized. The objectives of
this study were to investigate the presence of potential eastern old growth elements in several
urban forested natural areas around Shelby Co., TN and to compare these forests to the
Overton Park Old Forest State Natural Area in Memphis, TN to better understand how potential
differences in land use history may have shaped the studied forests. We used stratified random
plot sampling to obtain species composition, stem density, basal area, and coarse woody debris
measurements. We also obtained cores from a subset of the largest trees to estimate minimum
ages for each surveyed forest. We show that the studied urban forested natural areas meet
some, but not all, commonly employed criteria for old growth forest elements consistent with
ongoing recovery trajectories from anthropogenic disturbance. The studied forests are also
distinct in species composition, likely due to unique land use and disturbance histories.
Nevertheless, the urban forested natural areas of Shelby Co. harbor important native
biodiversity in a region that has experienced intensive historical anthropogenic disturbance.