Lake states aspen productivity following soil compaction and organic matter removal
General Technical Report Pacific Northwest Research Station, USDA Forest Service
S. Parker, S.S. Hummel
Beyond 2001: a silvicultural odyssey to sustaining terrestrial and aquatic ecosystems. Proceedings of the 2001 National Silviculture Workshop
Aspen (Populus tremuloides Michx. and P. grandidentata Michx.) provides wood products, watershed protection, and wildlife habitat for numerous game and non-game species across the northern Great Lakes region. Sustaining the productivity of these ecosystems requires maintaining soil productivity. Management activities that decrease soil porosity or remove organic matter can reduce productivity. We determined effects of three levels of soil compaction and organic matter removal (OMR) on aspen regeneration and growth following winter harvest of aspen-dominated stands in northern Minnesota, western Upper Michigan, and northern lower Michigan. Compaction treatments were applied to increase surface soil bulk density by either zero, 15, or 30 percent. The OMR treatments were merchantable bole harvest (MBH); total tree harvest (TTH); and total woody vegetation, plus forest floor removal (FFR). Soil compaction tended to increase mean sucker diameter and height on the sand and decrease them on the fine textured soils. Compaction greatly reduced sucker density and growth on the most productive silt-loam soil, primarily due to late spring treatment. These results apply to planning of operational harvest of aspen-dominated stands throughout the northern Great Lakes region. Sucker density increased with level of OMR on all three sites. On the sand site, mean diameter, height, and biomass were greatest with MBH and decreased significantly with increasing OMR, indicating a potential decline in productivity with repeated total tree harvesting on sand soils.
Stone, Douglas M. 2002. Lake states aspen productivity following soil compaction and organic matter removal. Proceedings of the National Silviculture Workshop, Hoor River, OR, USDA Forest Service, Pacific Northwest Research Station. General Technical Report PNW-GTR-546. 59-67.