Study site

A field survey was conducted in the Ansai County of Shaanxi Province, China (Figure ​(Figure1).1). Ansai County, located in the central part of the Loess Plateau, is well known for its extensive soil erosion. This area has a typical semiarid continental climate, with a mean annual temperature of 8.8°C and a mean annual precipitation of 549.1 mm. Precipitation varies seasonally, however, with 74.3% of it falling from June to September (Chen et al., 2007b; Sun et al., 2016a). Most native trees and shrubs were replaced by agricultural crops and were retained only at field edges and on gully slopes (Jiao et al., 2007). The current major land-use types are forest, shrubland, grassland, cropland, abandoned cropland, and residential areas in a mosaic rural landscape pattern (Jiao et al., 2012; Sun et al., 2016c). The typical vegetation currently found in the study area includes trees, such as Populus davidiana Dode., Robinia pseudoacacia Linn., and Quercus wutaishanica Blume; shrubs, such as Hippophae rhamnoides Linn. and Caragana korshinskii Kom.; and herbs, such as Stipa bungeana Trin. and Artemisia sacrorum Ledeb.

Location of the study site (Ansai County) on the Loess Plateau, China.