Short-term impacts of harvesting and burning disturbances on physical and chemical characteristics of forest soils in western Newfoundland, Canada

摘要

The short-term impacts of prescribed burning were determined for the physical and chemical properties of a forest soil on a clear-cut in western Newfoundland, Canada. The experimental site was predominantly covered by black spruce trees (Picea marianaMill.) that were harvested in 1996. In August 1998, prescribed burning removed most of the logging residues left on the site after harvesting, all above-ground surface vegetation, and parts of the upper humus layer. In October 1998, field samples were taken from four replicated burned plots and four replicated un-burned plots. In each study plot, soil samples were taken from the organic layer (F + H) and from the top 10 cm of the mineral soil. In the burned treatments, mass of the humus layer (F + H) was reduced by 24% and, because of the accretion of basic ash materials, acidity of the humus layer was also reduced by up to 1 unit. In the organic layer and the mineral soil, total contents of Mg, Ca, and P, extractable Mg and Ca, available P, sum of NH_4Cl-extractable cations, and C/N ratios were increased by burning, while total C and N as well as total and extractable K remained unaffected by burning.