景观高度异质区土壤有机质时空变化特征分析

Temporal and Spatial Characteristics of Soil Organic Matter for Landscape Heterogeneity Area

基于GIS和环境相关法,构建了集传统统计学、空间趋势分析、时间稳定性评估、结合辅助信息的地统计混合模型联合的景观高度异质区土壤属性时空变化研究模型,并利用该联合模型揭示了北京市密云县土壤有机质时空变化特征及其影响因素。结果表明,构建的时空联合模型能够较好地体现景观高度异质区土壤有机质时空变化细节特征;土壤有机质以中等稳定为主,且随着时间的推移,随机部分占土壤有机质空间变异的比例越来越大;不同时期土壤有机质含量空间分布格局一致;高土壤有机质含量区域的土壤有机质随时间呈减小趋势,低区与之相反,且高土壤有机质含量区变幅大,而低土壤有机质含量区变幅小;影响密云县土壤有机质时空变异的因素主要为土壤质地和土地利用方式。

A joint model of the temporal and spatial variation of soil properties was built, which integrated traditional statistics, spatial trend analysis, time stability assessment, and geostatistical hybrid model based on GIS. The joint model was used to reveal the spatio-temporal changes of soil organic matter and its influencing factors in Miyun County, Beijing. The results showed that the joint spatio- temporal model could preferably reflect the characteristics of soil organic matter（SOM） for high landscape heterogeneity in detail. SOM displayed medium time stability, and the random parts accounted for the spatial variability increased gradually. Patterns of spatial distribution of SOM content were consistent in different years. The SOM content in high value area gradually decreased over time, and increased in low value area. And the variation was large in high values range and small in low value area. The main factors impacting spatio-temporal variation of SOM were soil texture and land use in the study area.