Carbon sequestration resulting from bottomland hardwood afforestation in the Lower Mississippi Alluvial Valley

Increasing abandonment of marginal agricultural lands in the Lower Mississippi Alluvial Valley (LMAV) and rising global atmospheric carbon dioxide (CO2) levels create a need for better options of achieving rapid afforestation and enhancing both below and aboveground carbon sequestration. This study examines the responses of six mixtures of bottomland hardwood species to fertilizer and herbaceous release treatments as a means of enhancing afforestation and carbon sequestration in the LMAV. A completely randomized design with 6 x 2 x 2 factorial arrangement of treatments was employed on sites near Cleveland and Greenville, MS. Dormant unrooted cottonwood cuttings and bare-root (1-0) seedlings of all other species were planted in spring of 2006. First-year survival ranged from 50 to 80 percent for red mulberry, green ash/ oak mix, NRCS species mix and an oak mix. Cottonwood monoculture and cottonwood/oak mix plantings showed survival below 40 percent. Very little differences in first-year growth were noted among the various planting types. Soil carbon prior to planting constituted more than 99 percent of the ecosystem carbon. We expect a shift and redistribution of carbon pools as the site transitions from herbaceous vegetation to forest.