Development of a protocol for monitoring status and trends in forest soil carbon at a national level

摘要

The national Forest Health Monitoring (FHM) program requires protocols for monitoring soil carbon contents. In a pilot study, 30 FHM plots loblolly/shortleaf (Pinus taeda L./Pinus echinata Mill.) pine forests across Georgia were sampled by horizon and by depth increments. For total soil carbon, approximately 40/100 of the variance was between plots, 40/100 between subplots and 20/100 within subplots. Results by depth differed from those obtained by horizon primarily due to the rapid changes in carbon content from the top to the bottom of the A horizon. Published soil survey information overestimated bulk densities for these forest sites.