[Spatial autocorrelation analysis on soil organic carbon distribution in Henan Province]

With spatial autocorrelation analysis, this paper studied the temporal and spatial variations of soil organic carbon (SOC) storage in Henan Province during the period from the 1st national soil survey (1958) to the 2nd national soil survey (1985). The results showed that spatial auto-correlation indices could better describe the spatiotemporal variation of the SOC storage between the two soil surveys. The total SOC storage was 54.93 x 10(8) t in 1958 and 69.65 x 10(8) t in 1985, with an annual increase of 1%, and the SOC density had a trend of higher in southeast and west Henan, followed by north and central Henan, and east Henan. The SOC storage per unit area decreased more quickly in southeast Henan, with the maximum of 1.57% per year, while increased greater in east Henan, with an average rate of 5.27% per year. The spatiotemporal variation of SOC storage had a close correlation with the original SOC content, i. e., the higher the original SOC content, the more greatly the SOC storage decreased.