基于GIS的武功山山地草甸土壤有机质空间变异研究

摘要

The authors take the soil in a block mountain meadow of the core scenic area of Wugong Mountain from Jind-ing to Diaomazhuang area as the research object,There are 117 sampling spots located at 30 m × 30 m grid in the two lay-ers,(0~20 cm) and(20~40 cm) ,of meadow in the test region. Through soil organic matter determination,spatial varia-tion analysis of soil nutrients is analyzed by the conventional statistics and geological statistical methods, the Ordinary Kriging interpolation mapping is built based on GIS. Through the research and analysis on distribution characteristics and spatial heterogeneity of soil nutrients,it draws the conclusions as follows:①General descriptive statistical analysis con-cludes that the upper soil layer(0~20 cm) generally belongs to 2nd classes of organic matter soil,the lower part(20~40 cm)is to third class,and good integrity distribution is in the whole test region meadow.②Under the background of sampling distance of 30 m,the autocorrelation distance of the lower soil organic matter A0 is 474. 6 m and 260. 2 m re-spectively in the test region meadow,which are far more than 30 m sampling spacing. It means that the organic matter spatial block distribution is obvious,and the sampling is reasonable and effective.③The correlation coefficients of the meadow organic matter in the two layers of test region(C0/C0 +C)were 27. 85% and 28. 66% respectively,which is be-low the average level degree of spatial autocorrelation. And the spatial variability of soil organic matter would be affected by both human factors and natural factors.④According to Ordinary Kriging interpolation space mapping, the regional differences between the landform and the land use pattern of soil organic matter spatial distribution have been shown in the figure. The preliminary analysis shows that the causes of these differences mainly for altitude,landform,tourism activi-ties,soil factors such as the vertical development and so on.%以江西萍乡武功山核心景区的金顶—吊马桩一带的区块状山地草甸土壤为研究对象,对试验区草甸上(0~20 cm)和下(20~40 cm)两层土壤采用30 m×30 m网格共采117个样点,测定土壤有机质,采用常规统计和地统计学进行了土壤有机质的空间变异分析,并且基于GIS进行了普通克里金插值成图,通过对土壤有机质的分布特征以及空间异质性研究分析,得出结论如下:①根据常规描述性统计分析,试验区草甸土壤上层(0~20 cm)大体属于2类有机质土壤,下层(20~40 cm)大体达到3类有机质土壤,整体性分布较好;②在采样距离为30 m的背景下,试验区草甸的上、 下层土壤有机质的自相关距离A0分别为474.6 m和260.2 m,都远>30 m的采样间距,说明有机质空间区块性分布明显,采样合理有效;③试验区上、 下层草甸土壤中有机质的空间自相关性系数(C0/C0+C)分别为27.85%和28.66%,属于中等偏下程度的空间自相关,土壤有机质空间变异受人类因素和自然因素双重影响;④通过普通克里格空间插值成图,图中呈现出来的土壤有机质空间分布在地形和土地利用格局下都具有地区差异性,初步分析可知,造成这种差异的原因主要为海拔、 地形、 旅游活动、 土壤垂直发育等因素.