Preliminary Evidence of Deep Soil and CWD Carbon Burial and Storage in An Old-Growth Hemlock Forest, Adirondack Mountains, NY.

Northeastern forest soil carbon capture and storage is important given that aboveground accrual is dynamically equilibrated. Those that have posited soil C storage maximum have derived conclusions from shallow sampling (<30 cm). Yet, omnipresence pit-mound topography resulting from stochastic climatic events buries coarse woody debris (CWD) a/o inverts soil pedons. These phenomena play a significant role in old-growth ecosystem carbon storage and pedogenic trajectories where CWD burial and soil inversion may prolong their ability to store/capture carbon by making it bioclimatically unavailable and mixing genetic soil horizons in an unpredictable fashion. To this end we conducted a taxonomic survey of forest soil pedons in a randomly selected Adirondack, NY old-growth hemlock tract and 30 systematically random selected soil pits to an a priori layer of mineral soil >30 cm thick were established in a 25 x 15 m grid. The tract was flat (<5%), the canopy consisted of 270-360 yr hemlock (Tsuga canadensis), with total basal area and aboveground biomass of 39.2-59.0 m2/ha and 224-366 Mg/ha, and the soils are broadly described as Typic Haplorthods. Forest floor (Oi+Oe+Oa), Oi+Oe, Oa, and buried Oa horizon depths averaged 36.9±11.5 cm, 5.7±3.2, 26.1±15.5, and 33.3±12.0, respectively. Buried CWD (Ow) of three distinct colors and textures (i.e. Ow1-Ow3) was identified in half of the pits with an average thickness of 31.3±17.9 and a mineral soil layer >30 cm thick was reached at an average of 48.8±22.2 cm with respective ranges of 7-59 and 22-114 cm. Results buttress the argument that an understanding of ecosystem carbon storage potential requires deep soil sampling and further analysis of the taxonomic, pedogenic, and biochemical ramifications posed by CWD burial. The commonly held belief that forest carbon capture reaches stasis at 100-120 years following disturbance does not reflect all forests of the region specifically those with old-growth characteristics.