Mo B.,Gansu Forestry Academy |
Cai G.,Gansu Forestry Academy |
Yang L.,CAS Research Center for Eco Environmental Sciences |
Lu J.,Gansu Forestry Academy |
And 4 more authors.
Shengtai Xuebao/ Acta Ecologica Sinica | Year: 2013
Compared with sparse native grassland (CK), soil water content and exchange range, as well as balance characteristics were investigated in the soil depth of 0-210 cm with 20 cm interval in mature Caragana korshinskii shrublands located in different topographic locations in a typical semi-arid loess watershed during growing seasons in 2009- 2011. Soil water content ranged from high to low as CK, north, east and south slope in the depth of 30-130 cm, while as upper and middle position of south slope, CK, north and east slope in the depth of 150-210 cm, as well as upper, middle and lower position in south and north slope. Seasonal soil water declined in sequence of September, August, July, May, June and October. No regular change of soil water range value and variation coefficient was found under different terrain conditions. However, soil water range value and variation coefficient is active in the depth of 0-50cm, while relatively stable in the depth of 70-210 cm in vertical scales. No continuous soil water deficit was found in the drought years in succession, which serious soil water deficit was found in the first drought year, profit and loss balance in the second drought year, and slightly surplus in the third drought year. Obviously, terrain condition difference influenced soil water variation in a small watershed scale. But in a particular type of vegetation, plant factor would be key factor influencing soil water movement in the stable soil layer. The resplendent and consumption of soil water kept a balance status in mature Caragana korshinskii shrubland in this study. Results indicated that the response of vegetation growth was later than the soil moisture deficit (about one year), and vegetation growth can adapt to the soil water condition. This was mainly because relatively high soil water content in initial period can promote the vegetation growth conditions due to high available soil water resource. However, the relatively good growth conditions of Canagana korshinskii plants would consume more soil water than initial period and lead more soil water consumption. On the other hand, low available soil water would inevitable limit the vegetation growth and lead relatively lower soil water consumption. Source