黄土高原丘陵沟壑区柠条与沙棘冠层的持水能力

2011年5-10月,以黄土高原人工造林主要灌木树种柠条(Caragana korshinskii)和沙棘(Hippophae rhamnoides)为研究对象,通过测定冠层截留数据与冠层各组分持水能力,采用Pereira回归分析法和直接测量法,对柠条与沙棘的冠层持水能力进行了研究.结果表明:受不同因素的影响,两种方法测定的冠层持水能力有一定差异.回归分析法主要受植株叶面积指数(LAI)季节性变化与穿透雨观测方法的影响,得到的柠条与沙棘冠层最大持水能力分别为0.68 mm和0.72 mm;而直接测量法主要受冠层结构特征影响,得到的柠条与沙棘冠层最大持水能力分别为0.73 mm和0.76 mm.直接测量法得到的柠条各组分最大持水量依次为枝(0.31 mm)＞叶(0.27 mm)＞树干(0.15 mm),沙棘为树干(0.33 mm)＞枝(0.29 mm)＞叶(0.14 mm).

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

Aims Our objective is to study the canopy water storage capacity of shrubs, a key factor controlling rainfall interception, 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 communities. 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 Caragana 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, respectively. The direct measurement was mainly impacted by the canopy structure; the maximum water storage capacity 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.