祁连山南坡微地形下典型生态系统土壤蓄水能力差异.

[Objective] The aims of this study are to explore the variability of soil water storage capacity of typical ecosystems under microtopographic morphology in the Qilian Mountains, and to provide reference for further improvement of water holding capacity in the study area. [Methods] Qinghai spruce and alpine grassland distributing on different slope orientations of microtopography were taken as the research objects. A combination of field sampling and laboratory experiments was conducted to study the effects of different slope orientations on the soil water storage capacity of two typical ecosystems. [Results]（1) Soil moisture storage was gradually decreasing in the microtopographic sunny slope（alpine grassland) area along the rising slope, with the lowest soil moisture storage in the upper middle of the slope. The slope position has less influence on soil saturation water storage capacity as the potential water storage capacity of the soil.（2) The slope position also significantly influenced the soil water storage capacity of the shaded slope（Qinghai spruce), and the soil water storage capacity increased along the slope position, with the top of the slope being the slope with high soil water storage capacity. The potential water storage capacity of Qinghai spruce soils was significantly affected by slope position, and the potential water storage capacity of soils in the middle and upper slopes was significantly higher than that of other slopes.（3) There were obvious differences in the soil water storage capacity of the two typical ecosystems. The actual water storage capacity of the alpine grassland（sunny slope) soil was higher than that of Qinghai spruce at different slope positions, while the Qinghai spruce（shady slope) soil potential storage capacity at different slope positions was higher. The water capacity was significantly greater than that of the alpine grassland（sunny slope). [Conclusion] Enough attention should be paid to the work of soil and water conservation in the area from the middle to the top of the micro-topographic slope in the study area. The slopes below of upper slope are the key areas of soil water storage capacity of the two types of ecosystems in the micro-topographic. The areas from the middle to the down of the micro-topographic slope are the core areas of soil water storage capacity of the two types of ecosystems. [ABSTRACT FROM AUTHOR]