Restoration thinning impacts surface and belowground wood decomposition

Abstract

Abstract Forest thinning to protect the soil and improve hydrologic function is used to alter stand structure and increase residual tree growth. However, little is known about how surface and belowground wood decomposition (i.e., soil process changes) respond to aboveground vegetation manipulation. We determined mass loss of three species of wood stakes (loblolly pine (Pinus taeda L.), trembling aspen (Populus tremuloides Michx.), and Chinese pine (Pinus tabuliformis Carriere)) placed horizontally on the soil surface and vertically in the mineral soil after thinning a Chinese pine plantation in northern China. Restoration thinning treatments consisted of three levels of overstory removal (30%, 41% and 53% of the standing biomass) plus an unthinned control. Stakes were extracted every 12\u202fmonths for 2years, and then at 6\u202fmonth intervals until the end of the study (3.5\u202fyears). Surface stake mass loss was significantly greater (9.0%) in the 30% overstory removal treatment than the control, but overall mass loss at the soil surface was very low (