Study on the throughfall, stemflow, and interception of two shrubs in the semiarid Loess region of China

Abstract The Loess Plateau, China, has been subject to 40 years of re-vegetation predominantly with the xerophytic shrubs Caragana korshinskii and Hippophae rhamnoides. Throughfall, stemflow, canopy interception, and water storage capacity experiments for the two shrubs were conducted from May to September during the period 2009–2013. The results showed that the throughfall percentages averaged 62.4% and 70.1% of gross rainfall for H. rhamnoides and C. korshinskii, respectively, while stemflow accounted for 2.4% and 6.7% of the gross rainfall for the two shrubs. The rainfall threshold for stemflow generation was 2.46 and 1.06 mm for H. rhamnoides and C. korshinskii, respectively. The wetting front depths for the two shrubs in the area around the stems were deeper than away from the shrubs. The averaged percentages of interception loss in H. rhamnoides and C. korshinskii were 35.2% and 23.2%. Additionally, H. rhamnoides had greater water storage capacity per leaf area for each simulated rainfall intensity (mean, 0.59 mm; range, 0.28–0.88 mm) than C. korshinskii (mean, 0.44 mm; range, 0.26–0.52 mm). Canopy water storage varied temporally with the eight simulated rainfall intensities. For all the tested rainfall intensities, H. rhamnoides could store more water per dry biomass (mean, 0.72 g−1; range, 0.39–1.06 g−1) than C. korshinskii (mean, 0.49 g−1; range, 0.31–0.69 g−1). The present study can inform re-vegetation projects, water budget analyses, and modeling efforts aimed at understanding rainfall water movement within shrub communities in the semiarid Chinese Loess Plateau, China.