Abstract: This paper studied the differences of soil moisture and nutrients under shrub canopy and in open space as well as the effects of Reaumuria soongorica during its germination on the herb growth and vegetation composition in desert grassland of western Loess Plateau. Under shrub canopy, the soil water regime, especially in 30-110 cm layer, was better, and the soil silt and clay contents, especially in 0-10 cm layer, were much higher while the soil sand content was lower, as compared with those in open space. The soil organic matter, total N, P, and K, and available N, P, and K were more enriched under shrub canopy, with the enrichment rate being 1.40, 1.25, 1.04, 1.05, 1.37, 1.77, and 1.49, respectively. From shrub canopy to open space, the herb plant coverage and height decreased, while the species richness increased. The relative interactive intensity of R. soongorica to herb plants density, coverage, and height were positive, whereas to herb plants species richness was negative. These results suggested that shrub R. soongorica had obvious “fertile island” effect, and had promotion effect on the growth of underlying herb plants.

Key words: Loess Plateau, Land use, Landscape diversity, Dynamics