中文摘要：

钾（K）是植物生长的必需元素之一，土壤中K含量主要受多种因素的影响。由于森林经营活动和树种组成不同，森林土壤中K含量差异性较大，表现一定的空间异质性。本研究在1hm2石栎-青冈栎常绿阔叶林样地内的10m×10m小样地中心位置，分采集0～10、10～20和20～30cm层的土壤样品，测定土壤中K元素含量，用地统计学理论分析土壤K含量空间变异特征，研究土壤K含量与土壤其它养分元素f有机C、N、P1、地形因子（海拔、凸凹度和坡度）和凋落物量之间的关系。结果表明：0～30cm土壤K含量平均值为28．04g/kg，为中等变异强度，具有明显的空间异质性。除20～30cm土层中K含量符合线性模型外，0～10＼10～20土层和0～30cm土层K含量符合球状模型分布，各土层土壤K含量具有较强的空间自相关性。0～10、10～20、20～30cm和0～30cm土层中K含量的空间自相关变程范围分别为37．51、25．38、39．78和28．92m，土壤K含量有较小的空间异质性尺度。各土层K含量随地形的变化趋势较为明显，表现为斑块状空间分布，低值出现在中下部的山脊，高值出现在上部山脊和西南角的部分沟谷。土壤K含量与海拔高度、土壤粘粒含量呈显著的正相关，K含量的空间异质性主要受成土母质和地形等结构因素影响。

英文摘要：

Potassium （K） is one of the essential nutrient elements that support plant growth. Soil K concentration could be strongly influenced by many factors in forest ecosystems. Thus, forest soil K concentration showed spatial heterogeneity due to different historical management and tree species composition. In this study, soil samples at 0 - 10,10 - 20 and 20 - 30 cm depth were collect at center in 10 m × 10 m subplot in a Lithocarpus glaber-Cyclobalanopsis glauca evergreen broadleaved forest. Based on geostatistics theory and spatial analysis functions, spatial heterogeneity of soil K concentration in the forest was investigated by using semivariogram of geostatistics. The results showed that the average K concentration of soils at 0 - 30 cm depth was 28.04g.kg-1 and coefficient variability was at the intermediate range with an obviously spatial heterogeneity. While linear variogram function was best fitted to soil K concentration at 20 - 30cm depth, spherical variogram model was best fitted to soil K concentration at 0 - 10, 10 - 20 and 0 - 30cm depths, indicating a strong spatial dependency. The spatial correlation distances （range） of K concentrations were 37.51 m for soil of 0 - 10 depth, 25.38m for soil of 10 - 20cm depth, 39.78m for soil of 20 - 30cm depth, and for soil of 0 - 30 cm depth. Soil K concentrations across all layer exhibited a clear patch distribution pattern, with the lowest values at the middle and lower ridge, and the highest values at upper and southwestern comer. Soil K concentration was significantly correlated with altitude and soil clay content, implying that soil spatial heterogeneity could be attributed to pattern material and topographical factors.