SOIL ORGANIC CARBON IN MID-ATLANTIC REGION FOREST SOILS: STOCKS AND VERTICAL DISTRIBUTION

Abstract

Soil contains the largest terrestrial pool of organic carbon (Boschi et al., 2018) and temperate forest soils have been a major sink for atmospheric carbon; however, determining the size of the soil organic carbon stock can be problematic. Sampling practices vary for sampling depth, and determining the density of the soil. The aforementioned standard practices need to be revised if the size of SOC stocks are to be accurately quantified, to establish a global SOC baseline.

A soil monitoring of 414 forested sites within 11 national parks in the National Capital Region (Schmit, 2014) was conducted over 10 years. Samples were collected from the leaf litter and each soil horizon to 1 meter depth. Soil bulk density (Db) was determined by the core method for the A horizons, and proxy Db values were investigated for the subsoil. The vertical distribution of SOC concentration and stocks were evaluated with respect to soil order, physiographic region/landform, drainage class and parent material.