Pores;f;ology Management ELSEVIER Forest Ecology andManagement 90 (1997) 161- 169 Recovery status of a tupelo-cypress wetland seven years after disturbance: silvicultural implications W. Michael Aust a, * , Stephen H. Schoenholtz b, Thomas W. Zaebst a, Beth A. Szabo b ’ Virginia Polytechnic Institute and State University, Blacksburg, VA, USA b Mississippi State University, Mississippi. MS, USA Abstract Three disturbance treatments were imposed on a palustrine forested wetland (Nyssa aquatica-Taxodium distichum) located in southwestern Alabamain 1986: (i) clearcuttingwith helicopterlog removal@ELI), (ii) HELI followed by rubber-tired skidder traffic simulation (SKID) and (iii) HELI followed by removalof all vegetation during the first two growing seasons via glyphosate herbicide application(GLYPH). After two growing seasons, it was hypothesized that eventualwoody plant growth would he best in the HELI-treatedareas, because SKID plots had reduced rates of water movement and soil aeration. However,measurements at stand age seven yearsindicate that SKID actually has greater total above-ground biomass (65979 kg/ha) than HELI (46748 kg/ha) and SKID plots have a higher proportion of the most desirable timberspecies (Nyssa aquatica). GLYPH areas resemble freshwater marshes, although the areas arebeinginvaded by Salix nigra seedlings. All disturbance treatments havesignificant groundflora components that haveincreased sediment accumulation 70-175% relative to an undisturbed reference area. By age seven years,regrowth of vegetation haslowered the water tableduringthe growingseason but has had little effect on soilredoxpotential andpH. Our observations suggest that this wetland system is rapidly recovering from logging disturbance seven years ago. Keywords: Timber harvesting; Forested wetlands 1. Introduction Timber harvesting operations in forested wetlands have been increasingly scrutinized by the general public and by agencies authorized to implement the Federal Water Pollution Control Act (Tolliver, 1993). Public and agency concerns about timber harvesting in forested wetlands have revolved around issues such as maintaining site hydrology and productivity, water quality, and biodiversity (Walbridge, 1993). l Corresponding author. Information is neededto assess the effects of timber harvesting in forested wetlands becauseof potential consequences involving alterations of water table level, soil saturation, oxidation-reduction dynamics, decomposition,nutrient availability and species com- position (Gosselink et al., 19901,which are deterrni- nants of productivity, biodiversity and water quality. Alterations in vegetation and hydrology may also cause responses in erosion-deposition dynamics within forested wetland systems(Aust et al., 1991; Perisonet al., 1993) and subsequentlyaffect nutrient input-export fluxes (Johnston, 1991). Several studies of initial impacts of timber harvesting in southern 0378-I 127/97/$17.00 Copyright 0 1997 Elsevier Science B.V. All rights reserved. PII SO378- 1 127(96)03899-6