[Studies on spatial heterogeneity of soil respiration in a subalpine meadow]

We measured soil respiration (R) and the environmental factors influencing Rs including soil temperature ( T, ) , soil water content (SWC) and soil organic carbon (SOC) in a subalpine meadow in Yundin mountain of Shanxi province, and performed an analysis of the heterogeneity of Rs, T10 and SWC and SOC as well as their relationships using both traditional statistics and geostatistics methods. The results from traditional statistics showed that the measured data of R and the environmental factors exhibited a normal distribution with variation coefficients ranging between 12% and 24%. The variation of all the measured factors was in the middle range. The fact that the correlation coefficient between Rs, and SOC (r =0. 61) was larger than that between Rs, and T15(r =0. 27) and SWC (r = 0. 26) indicates that the heterogeneity of Rs was controlled mainly by SOC. The results from geostatistics analyses showed that linear model could reflect the spatial characteristics of Rs and the environmental factors. The C0/(C0 + C) values for Rs, T10, SWC and SOC were 41% , 3% , 77% , and 57% , respectively, indicating that the spatial heterogeneities of both RB and T10 were resulted mainly from structural factor, but the spatial heterogeneities of SWC and SOC were controlled mainly by random factor. The range of semi-variogram function was 53. 2 m for Rs, T, and SWC, and 52. 1 m for SOC. The fractal dimension value of Rs, T10, SWC, and SOC was 1. 85, 1. 60, 1. 96, and 1. 95, respectively, indicating that SWC had the weakest spatial dependence on scale and the most complicated spatial distribution pattern, while T10 had the simplest spatial distribution pattern. The spatial distribution of Rs showed a similar distribution character to both SWC and SOC, but had its own regularity. With the decrease of the confidence level and the estimated accuracy, the required sampling number of the Rs and the environmental factors measurements declined substantially.