山地林道网对林地环境的影响

Effects of Mountain Forest Road Network on Forest Land Environment

山地林道网对林地环境影响的定量研究是一个重要的却一直未被重视的领域。采用定点观测与面上调查相结合的方法 ,定量研究山地林道网对林地土壤性质、土壤侵蚀量和植被的影响 ,分析其成因 ,揭示山地林道网对林地环境影响的机理。其研究结果可为定量评价森林作业系统对林地环境所产生的负面影响提供依据。

Quantitative researches on the effects of mountain forest road network on the environment in forest land were ignored in past. Soil samples collected from all parts of forest roads which were built in different time and forest land were analyzed. The results indicates that compared with the forest land, the solidity of soil on the road surface is much higher The solidity of soil on the side slope of the new forest road is nearly the same as that on forest land. The nutrient contents of soil on the forest roads are much lower than those of soil on the forest land because of constructing forest roads. The nutrient contents of road surface and filling side are only 20～50% as much as those on forest land. The soil erosion of 20 temporary forest roads in the research area was investigated by means of Gully Survey and Relative Sediment. A power formula relationship among soil erosion yields on forest road surface and slope length, slope degree, and the years of abandoning maintenance was developed. The average relative error of the formula is 12.7% which can meet the need of soil erosion prediction. The research results can be the basis of the quantitative evaluations on the negative effects of forest harvesting system on the environment in forest land.