The effects of different logging techniques on the physical and chemical characteristics of forest soil

Abstract

In this study, we investigated the effects of four timber logging techniques (skyline, skidder, manpower and chute system) on the physical (permeability, field capacity, water holding capacity, bulk density, fine and coarse soil, sand, clay and silt ratios) and chemical properties (electrical conductivity, organic matter, total lime, P2O5, K2O, Ca, Mg, Na, Fe, Zn, Cu and Mn contents) of forest soil at two soil depths (0-15 and 15-30 cm) at loading, unloading, skid road, and undisturbed plots. The logging practices, each consisting of three steps, were executed at 12 testing sites in total, where logging through skylines, ground skidding with manpower, skidding with skidders, and sliding within the chute systems were performed. Our results demonstrate that logging by skidder and manpower can have an important influence on soil permeability, bulk density and soil water balance, and these techniques can significantly reduce soil organic matter content and nutrient levels. It was also noted that these two logging techniques constantly removed the litter and humus from the forest floor, reducing the amount of soil organic matter content and nutrients. The removal of organic matter content and nutrients from the soil will also affect soil organisms, which play an important role in regulating organic matter content decomposition rates.