Abstract: In order to provide reference data for water conservation modelling and to determine sustainable utilization and protection criteria for alpine meadow, factors influencing soil water holding capacity were assessed for microsites at different positions along a slope transect in the eastern Qilian Mountains. Five study plots at different altitudes (slope crest, 2990 m; upper slope, 2980 m; mid slope, 2970 m; lower slope, 2960 m and slope foot, 2950 m) were selected, and the soil particle size distribution (i.e. soil texture), soil moisture, soil bulk density, soil porosity and soil permeability were measured. Soil texture varied little between the slope crest, upper, mid, and lower slope or with soil depth at those sites (typically 8%-10% clay, 79%-83% silt, and 7%-11% sand); however, at the slope foot soil had 42% sand in the 0-10 cm soil layer, increasing with depth to 74% sand in the 30-40 cm soil layer, with corresponding reductions in silt and clay components. Soil field moisture capacity was negatively correlated with sand and clay content and positively correlated with silt content and was typically in the range 45%-55% for slope crest and upper, mid and lower slope positions, and was 40% for the 0-10 cm layer reducing to 21% for the 30-40 cm layer at the slope foot where soil had a higher sand content. Total soil porosity was generally similar to soil field moisture capacity, and showed a tendency to decrease with soil depth, while non-capillary porosity was somewhat variable with slope position and soil depth, and typically less than 8%. Infiltration rate decreased with increasing soil depth, but increased moving down the slope from crest to foot. At the slope crest, infiltration rates after 5 min testing were 1.2 mm·min^-1 for the 0-10 cm soil layer, decreasing to just over 0.2 mm·min^-1 in the 30-40 cm soil layer, while at the slope foot they were 4.4 mm·min^-1 for the 0-10 cm soil layer, decreasing to approximately 2.5 mm·min^-1 in the 30-40 cm soil layer. These data will assist with modelling of soil storage and release of water after rainfall events.

Key words: alpine meadow, soil particle composition, field moisture capacity, soil porosity