Abstract: By the methods of classical statistics and geostatistics, the spatial heterogene ity of surface soil (0〖KG-*2〗-〖KG-*7〗5 cm and 5〖KG-*2〗-〖KG-*7〗10 cm laye rs) moisture content in dry season in the typical sloping fields and depressions in Mulun National Natural Reserve in Karst area were studied. The results indic ated that in study area, the surface soil moisture content in dry season was sti ll higher, and showed a fine semivariogram structure as a whole. The spatial distribution of moisture cont ent in 0〖KG-*2〗-〖KG-*7〗5 cm and 5〖KG-*2〗-〖KG-*7〗10 cm soil layers, both for sloping fields and for depressio ns, fitted exponential model well. Under the same stand conditions, the moisture content in the two soil layers had the similar spatial structure and distributi on pattern; while under different stand conditions, there existed obvious differ ence in the same soil layer. The spatial pattern of surface soil moisture conten t in sloping fields was characterized by medium spatial autocorrelation, clear p atches with well continuum, relatively slow variation of Moran’s I index, while that in depressions was characterized by strong spatial autocorrelation, larger variation of Moran’s I index, and more fragmented patches. Therefore, topograp hy, micro-physiognomy, precipitation, human disturbance, and especially vegetat ion were the most important factors affecting the spatial pattern of soil moistu re content in the Mulun National Natural Reserve, and to preserve primary forest should have favorable effect on the regulation of the spatial heterogeneity of soil moisture content in the Reserve.

Key words: leaf water, Platycladus orientalis, kinetic fractionation coefficient., stable isotope