Effects of Forest Management and Elevated Carbon Dioxide on Soil Carbon Storage

This chapter addresses the effects of forest management and elevated carbon dioxide (CO₂) on soil carbon (C). Forest management may cause changes in soil C storage, affecting the atmospheric CO₂ levels, which in turn may affect both primary productivity and soil C storage. The recent literature review of forest management reconfirmed what has long been known: presence of nitrogen-fixing trees nearly always results in increased soil C and nitrogen (N). Elevated CO₂ may affect soil C by causing changes in primary productivity, litter quality, decomposition rates, root exudation, and turnover. Elevated CO₂ might also affect soil C indirectly by causing changes in soil CO₂ partial pressure, which may in turn affect root growth and decomposition. Soil C accumulation rates may also be indirectly affected by plant and microbial physiological responses to elevated soil carbon dioxide partial pressure (pCO₂). Increases in soil pCO₂ may have significant effects upon root growth and decomposer activity.