采伐干扰对林下草本根系生物量与土壤环境异质性关系的影响

结合统计学和地统计学的理论,探讨了采伐干扰对华北落叶松林下草本根系生物量空间异质性及与林下土壤含水量、全氮、硝态氮、铵态氮、pH及华北落叶松细根生物量空间异质性的关联性。结果表明,采伐干扰样地草本根系生物量为 31.17 g/m²,明显小于未干扰样地(72.01 g/m²);采伐干扰导致草本根系生物量更多地向表层积聚。0~10 cm土层,采伐干扰样地草本根系生物量的空间异质性(C₀+C=31330.0)和空间自相关性(C/C₀+C=92.5%)明显增强,表现出较强的空间依赖性。采伐干扰后,土壤水分、全氮、硝态氮和铵态氮对草本根系生物量的相关性增强;未采伐干扰样地华北落叶松细根生物量与草本根系生物量的相关性较强。

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.