干旱区生态环境知识资源中心

The spatial distribution of Reaumuria soongorica is characterized by a mosaic of patchy vegetation and bare area. However, little knowledge exists about the effects of these patterns on soil characteristics and water redistribution. The objectives of this paper are to study the effects of microscale distribution pattern Of Reaumuria soongorica on soil fertility, dust accumulation and soil water variation on loess slope. The results of this study indicated that the spatial discontinuous patchy distribution of Reaumuria soongorica had a positive influence on the soil properties of their surrounding soil, leading to fertile soil island under the plant canopy in the midst of bare soil surface. Organic matter content, nitrogen and cation-exchange capacity were higher in topsoil under Reaumuria soongorica canopy than in adjacent open areas. Moreover, Reaumuria soongorica affected water redistribution; soil water contents were generally higher under canopy than in inter-plant bare area and runoff decreased with increasing Reaumuria soongorica cover. Reaumuria soongorica canopy favored sedimentation by intercepting airborne dust, dust accumulations was significantly higher under canopy than in inter-plant bare area. The average total dust accumulation during 4 months between January and April in 2002 was 210g(.)m(-2) under plant canopy, 92g(.)m(-2) higher than that in inter-plant bare area.