Long-term stand growth after helicopter and ground-based skidding in a tupelo-cypress wetland: 21-year resultsThis article is part of a larger document. View the larger document here.
Three disturbance treatments were implemented on a tupelo-cypress forested wetland in southwestern Alabama on the Tensaw River in 1986: (1) clearcutting with helicopter log removal (HELI), (2) HELI followed by rubber-tired skidder traffic simulation (SKID), and (3) HELI followed by removal of all vegetation during the first two growing seasons via glyphosate herbicide application (GLYP). At year 2 the SKID treated areas were wetter and had dramatic negative changes in soil characteristics and hydrology. By year 7 these negative impacts of skidder traffic were ameliorated. Further, the SKID treatment resulted in increased regeneration of Nyssa aquatica. Water quality was not adversely impacted by any disturbance treatment and sediment accumulation was actually improved by both HELI and SKID treatments. At year 21 the SKID and HELI treatments are well stocked with over 4,000 stems/ha, but the GLYP plots have little woody plant regeneration. Despite large stand composition differences at year 7, the SKID and HELI plots are becoming more similar. This is largely due to a decreasing Salix nigra component. Aboveground tree biomass is also similar for the SKID and HELI treatments with no significant differences for any species.