Impact of Harvest Utilization, Site Preparation and Weed Control on Soil C and N in a Rotation Age Loblolly Pine Planttion.

The impact of harvest utilization (stem only vs whole tree), site prepareation intensity (chop and burn vs shear, pile, and disk) and competition control (none vs herbicide treatment) on soil C and N were evaluated in a 34-year-old loblolly pine plantation in the North Carolina Piedmont.  there were no significant impacts of harvest utilization on forest floor or mineral soil C or N, in spite of significantly higher removals of OM and N in the whole tree harvest compared to the stem only harvest. Forest floor C and N were greater in the shear, pile and disk treatment compared to the chop and burn treatment and in the herbicide treatment compared to the no herbicde treatments. Previous predictions that the more intensive harvest and site preparation treatments would lead to declines in forest floor and mineral soil C and N and thus negatively affect long term site productivity in this stand were not  confirmed by the data.  Thee results suggest that these loblolly pine plantation ecosystems may be more resilent that previously hypothesized.