Impacts of Mechanical Tree Felling on Development of Water Tupelo Regeneration in the Mobile Delta, Alabama

Two water tupelo (Nyssa aquatica L.) stands in the Mobile Delta of Alabama were selected to test the hypothesis that mechanizedfelling 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 assessedprior to harvest and annually for 3 yr after harvest infive, 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 27O/ac on each site regardless offelling 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, mechanicalfelling reduced water tupelo stump sprouting by 50% leading to a lower density of sprout clumps in mechanicallyf elledplots (P = 0.0253). Our results indicated that mechanicalfelling techniques used in this study may adversely impact regeneration of water tupelo swamps where coppice is a desirable form of reproduction. South.