Spatial heterogeneity of soil water content on surface land following reforestation in a semi-arid region
Junjun Yanga, Zhibin Heb,11Corresponding author. E-mail address: junjun_yang@126.com., Jianmin Fenga, Pengfei Linb, Jun Dub, Lingxia Guoa, Yufeng Liua, Meng Koua, Guohua Wangc, d, Jialiang Yane
a College of Resource & Environment and Historical Culture, Xianyang Normal University, Xianyang 712000, China
b Linze Inland River Basin Research Station, Chinese Ecosystem Research Network, Key Laboratory of Eco-hydrology of Inland River Basin, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China
c College of Geographical Sciences, Shanxi Normal University, Taiyuan 030000, China
d Key Laboratory of Desert and Desertification, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Science, Lanzhou 730000, China
e Institute of Geography Science, Taiyuan Normal University, Jinzhong 030619, Shanxi, China
Abstract :
The spatial pattern of soil water content (SWC) determines the success of vegetation restoration in semi- and arid regions. The Qilian Mountains in China are in a semi-arid area where decades of environmental degradation prompted large-scale restoration efforts with a native constructive species Picea crassifolia . However, the relationships between SWC and landcover are not clear in this area, hindering woodland restoration. In this study, we determined spatial distribution and characteristics of SWC in the Qilian Mountains in four main types of landcover. Our results revealed that 1. SWC decreased in the order of natural forest, brushland, grassland, planted forest, and mixed forest, but it was significantly different only in natural forest (p<0.05); 2. planted forest exhibited a lower SWC at young ages (less than 50 a) than natural forest, brushland or grassland, and the ecohydrological effect of afforestation exhibited hysteresis at long time scales; 3. a variogram analysis and Kriging interception of the spatial pattern of SWC showed that shrubland and grassland exhibited superior adaptability to local SWC compared with afforestation. The differences in SWC among various landcover types indicated that strengthening the maintenance and protection of natural forests is more important for restoration efforts than afforestation; furthermore, in semi-arid regions, shrubs and grasses are more suitable for use in ecological restoration than forest plantations.
Keywords: Soil water content, Spatial heterogeneity, Semi-arid region, Plantation, Kriging interception