北京松山自然保护区天然油松林土壤养分与坡位关系的研究

Study on Relationship Between Soil Nutrients and Slope Position in Natural Pinus tabulaeformis Forest Stand in Songshan Natural Reserve Administration, Beijing

为了阐明坡位对天然油松林地土壤养分状况的影响，并为华北地区天然油松林地的抚育管理提供科学依据，以北京市松山自然保护区内的健康天然油松林地的土壤为研究对象，对样地内上、中、下3个坡位的土壤主要养分含量进行分析测定，探讨林地内土壤主要养分含量与坡位的关系。结果表明：（1）土壤养分主要在下坡位汇集，各坡位油松林土壤全氮含量和速效钾含量：上坡位〉中坡位，而有效磷含量为：中坡位〉上坡位。（2）各养分元素主要集中于土壤表层，基本随土层深度的加深而降低；土壤全氮和有效磷含量分别在下坡位和中坡位出现了随土层深度加深而先降低后升高的趋势；（3）土壤速效钾含量在0-20cm土层深度表现为中坡位出现最低值，而在20-60cm土层深度表现为中坡住出现最高值。

In order to illustrate the effect of slop on the soil nutrients of natural Pinus tabulaeforrnis stand, and to provide reference for tending and managing the natural Pinus forest in north China. The author studied the relationship between soil nutrients and slope position （upper slope, middle slope, lower slope） by selecting a natural Pinus tabulaeformis stand in Songsha Natural Reserve, Beijing. The result showed that： （1） nutrient of total N, available P, and available K were mainly accumulated at the lower slope, but total N and available K ranked upper slope〉middle slope, while the available P ranked middle slope 〉upper slope in all the three slope positions. （2） Soil nutrients concentrated in top soil layer. Generally all nutrients decreased with soil depth, but total N in middle slope and available P in lower slope showed lowest value in the middle depth. （3） Available K was found the lowest value in the top layer, while the highest value was in 20-60 cm soil layer in the middle slope.