Shuitu baochi tongbao (Aug 2023)
Analysis and Simulation of Factors Affecting Soil Saturated Hydraulic Conductivity by Combinations of Grasses and Shrubs with Different Root Configurations
Abstract
[Objective] The impacts on soil saturated hydraulic conductivity that occur because of differences in root and soil properties between combinations of grasses and shrubs having different root configurations were studied, and an empirical equation for estimating soil saturated hydraulic conductivity was established by comprehensively considering root and soil properties in order to provide a theoretical reference for the establishment of hydrological models appropriate for conditions following vegetation restoration on the Loess Plateau. [Methods] Plots of grass-shrub mixtures having different root system configurations were used: Agropyron cristatum and Caragana korshinskii, and Artemisia gmelinii and Caragana korshinskii. Saturated hydraulic conductivity was measured by the double-ring knife method. [Results] The influence of sample grass-shrub mixture type and soil depth on soil saturated hydraulic conductivity was significant, and their factor contribution rates on soil saturated hydraulic conductivity were 26% and 52%, respectively. The soil saturated hydraulic conductivity of the tap-root grass Artemisia gmelinii and Caragana korshinskii mixture was greater than that of the fibrous root grass Agropyron cristatum and Caragana korshinskii mixture. Soil saturated hydraulic conductivity of different plots declined with increasing soil depth. Root length density, soil aggregates, and soil bulk density better simulated soil saturated hydraulic conductivity, with a fitting accuracy (R2) reaching 0.86. [Conclusion] The combination of a taproot grass and a shrub had a higher saturated hydraulic conductivity than observed for the combination of fibrous root grasses and shrubs. Root length density, soil aggregates, and soil bulk density were the main factors affecting saturated hydraulic conductivity.
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