Soil Carbon Distribution in High-Elevation Forests of the United States
This chapter summarizes data from the literature on soil carbon distribution and turnover in high-elevation forests, and examines whether high-elevation forest ecosystems will act as a source or a sink for atmospheric carbon dioxide in the event of global climate change. Despite that high-elevation forests occur to a limited extent in the United States, they play a unique role in carbon dynamics on a regional basis. Because high-elevation forests are often inaccessible, they commonly display an old-growth character including tree ages in excess of 500 years and high amounts of organic matter in above-ground biomass and coarse woody detritus. As with most ecosystems, the soil is the largest storehouse of organic C in high-elevation forests ecosystems. High-elevation forests often receive high inputs of nutrients and environmental contaminants due to orographic effects and cloud-water deposition. The response of subalpine forests to climate change is dependent on snowpack behavior and its effect on migration of tree line and expansion of tree islands.