不同沙丘下梭梭(Haloxylon ammodendron)主根周围土壤特征的差异性研究

Study on the Differences of Soil Characteristics in Root Zone of Haloxylon Ammodendron in Various Dunes

为探明沙漠建群种植物个体周围土壤养分和盐分空间分布及成因,对艾比湖湖区边缘三种类型沙丘下梭梭主根周围土壤含水量,电导率,全量养分和速效养分的变化进行了研究。结果表明：1固定性沙丘在表层（0~10 cm）处土壤含水量最小,流动性沙丘和半固定性沙丘在浅层（10~20 cm）处最小,以距离主根面3m处表现最为显著（P〈0.05）。2流动性沙丘和半固定性沙丘土壤有机质和全氮的结构性和空间自相关性均较弱,固定性沙丘养分（全量养分、速效养分）的结构性则较好。3三种沙丘土壤养分的空间分布不均,主要以条状和斑块状分布,整体上呈现出一定的集聚趋势,其中流动性沙丘和固定性沙丘集聚范围在0~2 m圈层,但纵向集聚范围中,流动性沙丘以浅层（10~20 cm）,固定性沙丘以较深层（20~40cm）出现集聚,形成＂肥岛＂。4流动性沙丘土壤电导率对沙丘的影响较其他各特征因子占主导地位,半固定性沙丘和固定性沙丘养分因子占主导地位。

In order to investigate the spatial distribution and causes of soil nutrients and salinity around the species in desert, this study explored water content, conductivity, total nutrient contents, and available nutrient contents of soil around the taproot in the three types of dunes at the edge of the Ebinur. The results were shown as follows：（1） Soil moisture was the minimum at 0- 10 cm away from the surface in the fixed sand dune but at 10- 20 cm in the migratory dune and semi-fixed sand dune. It was the most significant（P 〈 0. 05） at the 3m away from the taproot surface.（2） Both soil organic matter and total nitrogen were weak in structural and spatial autocorrelation in migratory dune and semi-fixed sand dune. However, total nutrient and available nutrient contents had superior constitutive property in the fixed sand dune.（3） The spatial distribution of soil nutrient was heterogeneous mainly in the form of strip and patchy and generally tended to be gathering. The gathering areas ranged from 0 to 2 m soil in the migratory dune and fixed sand dune. Longitudinally, nutrient gathered in shallow area（from 10 to 20 cm） in the migratory dune while in deep area（from 20 to 40 cm） in the fixed sand dune, thus forming the ＂Fertile Island＂.（4） Compared to other characteristic factors, soil conductivity played a dominant role in migratory dune, and the nutrient factor dominated in the semi-fixed sand dune and fixed sand dune.