Belowground nutrient dynamics following three harvest intensities on the Pearl River floodplain, Mississippi

The influence of clear and partial cut harvests on belowground nutrient cyc ling processes was examined on the Pearl River floodplain, Mississippi, Foc i examined by this study included fine root biomass and detritus, fine root production, fine root nutrient contents, soil respiration rates, and micro bial biomass C, N, and P during the first year post-harvest. Both the clear cut and partial cut initially reduced fine root biomass; however, fine root biomass levels within each treatment did not differ at this study's conclu sion, Bimonthly fine root production within both the clearcut and partial c ut declined initially following harvest; however, net primary production wa s greatest within the clearcut, followed by the partial cut, and lowest wit hin the control. Soil respiration rates showed strong seasonal trends; howe ver, increased soil respiration rates within the clearcut and partial cut w ere not found until almost 1 yr post-harvest. Decreased microbial biomass C levels were observed following both harvests. Only the clearcut treatment significantly reduced microbial biomass N. No treatment effects were found regarding microbial biomass P. Herbaceous and woody vegetation recolonizati on was vigorous within the clearcut and partial cut harvests, strongly infl uencing fine root production levels and soil respiration rates. It appears that fine roots from naturally recolonizing vegetation play a large role in belowground C storage following disturbance. The rapid increases in fine r oot production and biomass following both silvicultural methods indicates t hat, within these ecosystems, the negative influences of harvesting on belo wground C and nutrient pools may be short live.