The influence of clear and partial cut harvests on belowground nutrient cycling
processes was examined on the Pearl River floodplain, Mississippi. Foci examined
by this study included fine root biomass and detritus, fine root production,
fine root nutrient contents, soil respiration rates, and microbial biomass C,
N, and P during the first year post-harvest. Both the clearcut and partial cut
initially reduced fine root biomass; however, fine root biomass levels within
each treatment did not differ at this study's conclusion. Bimonthly fine root
production within both the clearcut and partial cut declined initially following
harvest; however, net primary production was greatest within the clearcut, followed
by the partial cut, and lowest within the control. Soil respiration rates showed
strong seasonal trends; however, increased soil respiration rates within the
clearcut
and partial cut were 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 recolonization was vigorous
within the clearcut and partial cut harvests, strongly influencing 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 root production and biomass following both silvicultural methods indicates
that, within these ecosystems, the negative influences of harvesting on belowground
C and nutrient pools may be short lived.