Water storage capacity of the canopy dominated by Caragana korshinskii and Hippophae rhamnoides in hilly and gully region on the Loess Plateau of Northwest China

Abstract

Aims Our objective is to study the canopy water storage capacity of shrubs, a key factor controlling rainfall in- terception, which affects a variety of hydrological processes in water-limited arid and semi-arid ecosystems. Vast areas of revegetated desert ecosystems in northwestern China are occupied by shrub and dwarf shrub communi- ties. Yet, data are scarce regarding their rainwater storage capacity. Methods From May to October 2011, the methods of Pereira regression and direct measurement were used to research water storage capacity by the interception data and water storage capacity of each component of Cara- gana korshinskii and Hippophae rhamnoides, the main artificial afforestation tree species in the Loess Plateau. Important findings There were some differences among the two methods due to effects of different factors. The regression analysis was mainly impacted by the measurement approaches of throughfall and leaf area index (LAI), with the maximum water storage capacity of 0.68 mm and 0.72 mm for C. korshinskii and H. rhamnoides, respec- tively. The direct measurement was mainly impacted by the canopy structure; the maximum water storage capac- ity was estimated to be 0.73 mm and 0.76 mm for C. korshinskii and H. rhamnoides, respectively. The direct measurement showed that the maximum water storage capacity per unit area of the canopy components was in the order of branches (0.31 mm) > leaves (0.27 mm) > trunks (0.15 mm) for C. korshinskii, and trunks (0.33 mm) > branches (0.29 mm) > leaves (0.14 mm) for H. rhamnoides.