Coarse Woody Debris in Southern United States Loblolly Pine Plantations: From Stand-Level to Regional Scales

Broad-scale estimates of coarse woody debris (CWD) yield across landscapes are somewhat rare, despite the importance of CWD in ecosystem functioning and its potential role in terrestrial carbon cycles. Yields of CWD were estimated at regional scales by linking a stand-level predictive model with regional forest inventory data for 11 states in the southern United States. We estimated that the accumulation of CWD in late-rotation loblolly pine plantations across the South totals 48.67 million metric tons of dry wood necromass, the carbon equivalent of 24.33 million metric tons. This represents annual CO2 emissions of 21 coal-fired power plants, or the amount of carbon sequestered each year in 7 million ha of pine forests. Confidence intervals for CWD dry weight per hectare generally did not exceed ±25% of the estimated values. Although county-level estimates were of higher uncertainty, the spatial pattern appeared to be relatively consistent with the extent of loblolly pine, with low yields near the extremes of the species' natural range and high yields in extensively forested portions of its range. Quantifying regional carbon stores of CWD with respect to stand-level management activities may improve accuracy of regional estimates and provide further insight into management effects on the carbon pool and the carbon cycle.