Erosion response of a harvested piedmont loblolly pine plantation in Alabama: preliminary resultsThis article is part of a larger document. View the larger document here.
The erosion impact of typical forest management operations in a loblolly pine (Pinus taeda L.) plantation in the Piedmont region of Alabama was investigated. Soil loss and runoff were highly variable throughout postharvest and first year after site preparation and planting. Under postharvest conditions, the annual rate of soil loss was 106.5 and 274.4 kg/ha in two locations (DIST1 and DIST2) of the harvest tract while annual rate of runoff was 141.4. and 200.4 mm/ha, respectively. The annual rate of soil loss after site preparation/planting varied by treatment in which orientation of planted beds or no beds were tested for its influence on erosion. The treatments consisted of beds oriented down the slope (DTS), across the slope (ATS), no bedding, and machine planting only (MPO). Soil loss was greatest on sites where beds were oriented DTS followed by sites subjected to MPO with no soil disruption prior to establishment of planting beds (MPO). The annual rate of soil loss from DTS and MPO was estimated to be 14 520 and 774 kg/ha and stands in contrast to erosion rates of 79.2 and 67.0 kg/ha for sites where beds were oriented ATS and where no disturbance took place, respectively. Nutrient mobilization was evaluated by determining chemical constituents of runoff collected after each precipitation event. In the postharvest phase, the total amount of base cations determined in runoff was estimated to be 6.81 and 4.60 kg/ha for DIST1 and DIST2, respectively. Cumulative totals of base cations were estimated to be 9.67 kg/ha in DTS and 3.57 and 3.19 kg/ha in MPO and ATS, respectively. Calcium and potassium were the most abundant elements in runoff while aluminum increased in runoff compared to postharvest conditions.