Effects of Cutting Disturbance on Spatial Heterogeneity between Root Biomass of the Herb and Soil Environment in Larix principis-rupprechtii Forests in Guandi Mountain

Based on theory and methodology of spatial pattern analysis in geostatistics, samples were taken at three soil depths (0-10 cm, 10-20 cm, and 20-30 cm) using soil core (7.0 cm in diameter). Effects of spatial heterogeneity between the herb fine root (≤2 mm)biomass of Larix principis-rupprechtii and soil characteristics (soil moisture, pH, total N, NO₃^--N, NH₄⁺-N) were analyzed. The results showed that herb root biomass was 31.17 g/m² in the disturbed stand (plot A), which was significantly less than that of the undisturbed plot (72.01 g/m²), and root accumulated in the upper soil layer. At the 0-10 cm soil layer, spatial heterogeneity (C₀+C=31330.0) and spatial autocorrelation (C/C₀+C=92.5%) enhanced obviously and exhibited a distinct spatial dependence in the disturbed stand.After cutting disturbance, the correlation between root biomass of herb and soil moisture, pH, total N, NO₃^--N, NH₄⁺-N increased. However, the correlation between herb root biomass and fine root biomass of Larix principis-rupprechtii was stronger in the undisturbed plot.