Water conservation capacity of typical forestlands in the Loess Plateau of Western Shanxi Province of northern China

ObjectiveThis paper aims to evaluate the water conservation capacity of typical forests and provide a basis for the selection and management of water conservation forests and soil and water conservation forests in the Loess Plateau of western Shanxi Province, northern China.

MethodIn this study, secondary mixed forest of Quercus liaotungensis and Populus davidiana, Pinus tabuliformis, Platycladus orientalis, and Robinia pseudoacacia in Caijiachuan Watershed of Jixian County, Shanxi Province was observed. In addition, we analyzed water conservation capacity of each forest type according to water holding capacity of vegetation, litter and soil with the entropy weight method.

Result(1) Water-holding capacity of vegetation layers of P. tabuliformis forest (17.79 t/ha) was the largest in four types of forests, followed by P. orientalis forest (13.55 t/ha), R. pseudoacacia forest (12.81 t/ha) and secondary mixed forest of Q. liaotungensis and P. davidiana forest (6.71 t/ha). Arborous layer was the primarily water-holding layer in Q. liaotungensis forest and P. orientalis forest and herb layer was the primarily water-holding layer in secondary mixed forest of Q. liaotungensis and P. davidiana forest, while the water holding capacity of arborous layer, shrub layer and herb layer in R. pseudoacacia forest was similar. (2) The water-holding capacity of litter of 4 forests was showed as secondary mixed forest of Q. liaotungensis and P. davidiana forest (23.02 t/ha), P. orientalis forest (13.00 t/ha), R. pseudoacacia forest (10.36 t/ha), and P. tabuliformis forest (2.81 t/ha), respectively. (3) Moreover, the maximum water-holding capacity of soil layer of 4 forests was showed as secondary mixed forest of Q. liaotungensis and P. davidiana forest (3 182.43 t/ha), P. tabuliformis forest (3 176.67 t/ha), P. orientalis forest (2 995.3 t/ha), and R. pseudoacacia forest (2 803.5 t/ha), respectively. (4) The water conservation capacity evaluation results indicate that herb layer and litter layer are the main factors, with the order of secondary mixed forest of Q. liaotungensis and P. davidiana > P. orientalis plantation > P. tabuliformis plantation > R. pseudoacacia plantation.

ConclusionTherefore, from the perspective of water conservation, measures should be taken such as afforestation, comprehensive management of secondary forest, forbidden grazing and improve the vegetation structure to increase soil and water conservation benefit.