马尾松人工林土壤养分空间分布特征及其与地形因子的相关性分析

在贵州省平坝区马尾松人工林可持续经营试点区域，设置80 m×120 m的样地，以10 m×10 m的标准网格采集土样，分析7种土壤养分的有机质、全氮、速效氮、全钾、速效钾、全磷、速效磷空间变异特征，并对土壤养分与地形因子之间的关系进行分析。结果表明：7项土壤养分指标均为中等程度变异，变异系数由大到小依次为全钾>全磷>有机质>速效钾>速效磷>速效氮>全氮；有机质、全钾、速效氮、全磷表现出比较强的空间自相关，而全氮、速效钾、速效磷表现出中等程度的空间自相关；速效磷和全磷的空间分布连续性相对最好，其次为全氮、全钾和速效钾，空间分布连续性最差的是有机质和速效氮，破碎化程度高。高程、坡度、坡向、地形起伏度、曲率是影响马尾松人工林土壤养分空间分布的主要因子。

Spatial Distribution Characteristics of Soil Nutrients and the Correlation with Topographic Factors in Pinus massoniana Plantation

In the pilot area of sustainable management of Pinus massoniana plantation in Pingba District, Guizhou Province, soil samples were collected in a standard grid of 10 m×10 m to analyze the spatial variability of 7 soil nutrient indicators (organic matter, total nitrogen, available nitrogen, total potassium, available potassium, total phosphorus, available phosphorus) and also discussed the correlation between soil nutrients and topographic factors. The results showed that seven soil nutrient indexes exhibited medium spatial variability, and the variation coefficients from large to small were total potassium > total phosphorus > organic matter > available potassium > available phosphorus > available nitrogen > total nitrogen. Organic matter, total potassium, total phosphorus and available nitrogen showed a relatively strong spatial autocorrelation, while total nitrogen, available potassium and available phosphorus showed a moderate degree of spatial autocorrelation. The spatial distribution of available phosphorus and total phosphorus had a relatively good continuity, followed by total nitrogen, total potassium and available potassium, organic matter and available nitrogen had a poor spatial continuity with higher degree of fragmentation. The elevation, slope, aspect, topographic relief and curvature were the main factors affecting the spatial distribution of soil nutrients.