No abstract

Three 4-yr-old stands (or locations) were selected for treatment. Treatment consisted of two components: (1) thinning water tupelo (Nyssa aquatica L.) stump sprouts and (2) cutting all stems of Carolina ash (Fraxinus caroliniana Mill.) and black willow (Salix nigra Marsh.) (cleaning). Contrary to results in other areas, survival of water tupelo coppice was very high and was not affected by the treatments. Cleaning had little or no positive effect on the individual tree or stand-level variables we measured. Thinning sprout clumps significantly increased diameter growth of water tupelo; the effect of thinning was considerably larger for one location. Stand basal area growth was decreased by thinning sprout clumps. However, quadratic mean diameter was increased by thinning, particularly at one location. Although thinning decreased basal area 5 yr after treatment, the increase in quadratic mean diameter was sufficient for there to be no significant effect of thinning on total volume 5 yr after treatment. Because of this, and in anticipation of imminent natural thinning of the unthinned plots, we suspect that the thinned plots will eventually have significantly greater standing volume than the unthinned plots, at least for the location where density of large sprouts was initially the highest. Rotation age will be decreased for that stand because stems will achieve merchantable size sooner. Thus we consider precommercial thinning of sprout clumps to be a potentially effective practice in stands with a high density of large water tupelo sprouts. South. J. Appl. For. 25(4):165–172.

Two water tupelo (Nyssa aquatica L.) stands in the Mobile Delta of Alabama were selected to test the hypothesis that mechanized felling does not reduce establishment and growth of natural water tupelo regeneration relative to traditional tree felling with chainsaws. To test the hypothesis, we established six, 2 ac treatment plots in each of two blocks on each of two sites, and randomly assigned plots to either mechanical tree felling with a tracked, swing feller or chainsaw felling. Each site was clearcut in Fall, 1992, and merchantable boles were removed by helicopter. Establishment and growth of regeneration was assessed prior to harvest and annually for 3 yr after harvest in five, 0.01 ac measurement plots located in each treatment plot. Stand harvesting promoted establishment of water tupelo seedlings such that 3 yr after treatment we recorded over 270/ac on each site regardless of felling method. Seedling height increased at a steady rate and averaged about 39 in. tall after three growing seasons. Woody competition also responded to the harvest, outnumbering water tupelo seedlings 3 yr after treatment by as much as seven to one on Site 2. Water tupelo stump sprouts developing from chainsaw felling grew well and averaged about 13.5 ft tall after three growing seasons. However, mechanical felling reduced water tupelo stump sprouting by 50% leading to a lower density of sprout clumps in mechanically felled plots (P = 0.0253). Our results indicated that mechanical felling techniques used in this study may adversely impact regeneration of water tupelo swamps where coppice is a desirable form of reproduction. South. J. Appl. For. 24(2):65-69.