干旱区生态环境知识资源中心

To understand the ecological significance of arbuscular mycorrhizal (AM) associations in arid ecosystem, the spatial patterns of AM fungi, glomalin and soil enzymes were surveyed at four sites located in the Otindag sandy land, northern China. Soil samples in the rhizosphere of Caragana korshinskii Kom. were collected at 0-10, 10-20, 20-30, 30-40 and 40-50 cm depth in July 2009. The study showed that C. korshinskii Kom. could form strong symbiotic relationship with AM fungi. AM fungal colonization, spore density, total Bradford-reactive soil protein (T-BRSP) and easily extractable Bradford-reactive soil protein (EE-BRSP) significantly differed among four sites and soil depths. Correlation analysis showed hyphal colonization had positive correlation with soil urease (P < 0.01). Spore density, T-BRSP and EE-BRSP were positively correlated with soil organic carbon, available N and P, and soil urease, acid phosphatase and alkaline phosphatase (P < 0.01). Based on stepwise regression, soil urease, available N and organic carbon were principal soil factors affecting the spatial distribution of AM fungi and glomalin. The results support the conclusion that glomalin may be an appropriate index for evaluating soil fertility. Moreover, the spatial distribution pattern of AM fungi and glomalin are useful to monitor desertification and soil degradation.