Rainfall partitioning characteristics of three typical sand-fixing shrubs in Horqin Sand Land, north-eastern China

Rainfall partitioning by vegetation affects water balance and utilization by plants. Caragana microphylla, Hedysarum fruticosum, and Salix gordejevii are three typical, morphologically different sand-fixing shrubs in Horqin Sand Land. However, few studies have compared rainfall partitioning by these shrubs. We examined rainfall partitioning differences among these shrubs in Horqin Sand Land, north-eastern China. On average, throughfall, stemflow (SF), and interception for C. microphylla accounted for 64.2, 11.0, and 24.8% of the individual incident rainfall, respectively; for H. fruticosum, they accounted for 71.2, 6.3, and 22.5%; and for S. gordejevii, they accounted for 75.3, 5.3, and 19.4%. The average funneling ratio for H. fruticosum (162.7 ± 33.2) was larger than that for C. microphylla (100.1 ± 16.9) and S. gordejevii (106.2 ± 23.1). Rainfall partitioning was significantly correlated with canopy area, branch number, and stem basal area for C. microphylla and S. gordejevii. SF volumes of 3,167, 676, and 2,210 L were estimated to have channeled into the plots for C. microphylla, H. fruticosum and S. gordejevii, respectively, indicating that C. microphylla is more effective in channeling SF to the root zone. These results suggest that C. microphylla may be more advantageous for sand-fixing and vegetation restoration in sand lands.