[Fractal dimension characteristics of soil particle size distribution under different vegetation patches in desert steppe and its relationship with soil nutrients]. / è’æ¼ è‰åŽŸä¸åŒæ¤è¢«å¾®æ–‘å—åœŸå£¤ç²’å¾„åˆ†å¸ƒåˆ†å½¢ç‰¹å¾ä¸Žå »åˆ†çš„å ³ç³».

ABSTRACT

Soil samples from four vegetation mini-patches (Artemisia scoparia, Glycyrrhiza uralensis, Sophora alopecuroides, Astragalus melilotoides) in a desert steppe in central Ningxia were collected. Soil physico-chemical properties including soil particle-size distribution, organic matter, pH, EC, total N, total K, total P of three depths were measured. The fractal dimension of particle size distribution characteristics of soils derived from four different vegetation mini-patches and their correlations with soil physico-chemical properties were examined. The results showed that patch vege-tation distribution affected the distribution of soil particle size, with the A. melilotoides mini-patch being the highest (D=2.51) and G. uralensis mini-patch being the lowest (D=2.46). There were significant positive correlation between fractal dimensions and the contents of clay and silt, and nega-tive correlation between fractal dimensions and sand content. Fractal dimensions were positively correlated with pH value and EC, negatively correlated with the contents of soil organic matter and total N, and had no correlation with the contents of soil total K and total P. The patchy vegetation distribution had potential trends of salinization and degradation.