关键词: 落叶松人工林, 土壤性质, 主成分分析, 大兴安岭

Abstract:

Impacts of artificial forests, being a special category of biological communities under human interference, on soil properties, have long been an issue of controversy. Hence, a tract of Larix plantation, quite common in the area, and three tracts of other natural types of vegetation ( Quercus mongolica, Prunussibirica and grassland) under similar natural conditions were selected in the South Da Hinggan Mountains for investigation of impacts of vegetation on soil properties. Results show that the soils under the four types of vegetation were all silt loam in texture, and 1.06 g·cm^-3(Quercus mongolica),1.07 g·cm^-3(Larix  spp.), 1.21 g·cm^-3(Prunussibirica) and 1.23 g·cm^-3(grassland) in bulk density, 0-40 cm in depth, indicating that the soils under the artificial  Larix plantation and natural Quercus mongolica woodlot were better than those under the two others in aeration and moisture retention. Analysis of soil chemical properties shows that all the items of soil nutrients, i.e. organic matter, total nitrogen, total phosphorus, and total potassium, in the soils under all the four types of vegetation, except for total N in the deep soil layers under grassland, were up to Criteria Grade I of the Standard for Soil Nutrients for the Second National Soil Survey. However, soil nutrients decreased in content with increasing of soil depth. The soil under the artificial  Larix woodlot was 5.84 in pH, right in the range of soil acidity (5.5-6.8) for natural  Larix  forests to survive in. And principal component analysis shows that the soil under artificial  Larix woodlot was better than that under grassland, but slightly worse than that under Quercus mongolica in soil properties. Based on the above findings, it could be concluded that the plantation of  Larix forest would not lead to deterioration of soil properties.

Key words: artificial Larix forest, soil property, principal component analysis, Da Hinggan Mountains