Soil moisture driven by vegetation restoration on the Chinese Loess Plateau: a synthesis and meta-analysis

Abstract

Vegetation plays a pivotal role in mitigating soil erosion in China’s Loess Plateau, but the management of soil moisture is equally crucial. This study reviewed 112 relevant research papers on the correlation between vegetation and soil moisture in the Loess Plateau. A meta-analysis systematically evaluates the impact of different vegetation types (woodland, shrubland, and grassland) on soil moisture since the initiation of the grain for green project in 1999, a large-scale government initiative. The results showed that in the vegetation construction of the Loess Plateau, the degree of soil moisture declined from large to small was woodland, shrubland, grassland, and became more serious with the increase in soil depth. Through subgroup analysis, it was found that the soil moisture of woodland and shrubland decreased with increasing rainfall; in various altitudes, the soil moisture of all vegetation decreases with increasing altitude; in different slope ranges, the decrease in soil water content of all vegetation construction was the greatest at 25° and the smallest at 15–25°; throughout the growth stages of vegetation, soil moisture consumption by trees increased with vegetation age, but the degree of water depletion did not further increase at 30 years for shrubland and 20 years for grassland. Therefore, from the perspective of soil moisture alone, shrubs and herbs are more suitable for establishment in the Chinese Loess Plateau than tree vegetation.