The effects of bucket mounding site preparation on the processes and functions of a subboreal mineral wetland.

摘要

Natural pit and mound microtopography is common in wetlands throughout the Upper Great Lakes Region. Many of these mounds are created by tree uprooting which serves to homogenize the soil by mixing subsoil with surficial organic materials and surface soil. Uprooting may also serve to translocate material from the upper soil horizons, down the profile through root channels (Cremeans and Kalisx 1988).; Tree throw mounds are favored microsites for tree establishment (McClellan et al 1990). IN wetland areas, the distribution of elevations among microtopographic features is likely the determining factor affecting the growth and abundance of wetland vegetation (Niemela 1999, Ehrenfeld 1995). Mounds in wet areas serve to increase aerated soil volume above the water table and increase potential rooting depth of seedlings.; Bucket mounding is a mechanical site preparation technique being used to regenerate cut over Lake States Forested Wetlands. Mounding is similar to windthrow mounds in that elevated planting sites are created by covering forest floor material with mineral soil. The goals of this study were to determine the effects of bucket mounding site preparation on the key wetland processes of hydrology, productivity, and carbon storage. Treatments included two bucket mounded plantations and a control.; Bucket mounding did not effect hydrology as measured by depth to water table. Additionally, bucket mounded plantations were growing faster than the control treatment, and were exhibited decreased overstory diversity. Total site carbon storage was most affected by removal of the overstory and disruption of the forest floor layer during harvesting. Additionally, changes in groundstory vegetation have effected site carbon recovery. Groundstory vegetation in the bucket mounded treatments is dominated by pioneer woody species, while the control is dominated by mosses and grasses. Over time, the groundstory species composition should shift in the bucket mounded plantations so as to more closely resemble the control.; Overall, bucket mounding has not affected the key wetland processes of hydrology, productivity, and carbon storage. These results should further increase the use of bucket mounding bucket mounding throughout the Region.