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土壤磷的生物有效性是陆地生态系统安全和初始生产力的重要影响因素.土壤中磷的生物有效性由其形态组成决定.常用的磷形态分类方法是Hedley提出的连续提取法,即通过不同化学强度的提取剂对土壤样品进行分步提取,各级提取剂提取出的磷被定义为不同形态的磷.近年来又推出了X射线吸收近边结构法(XANES),利用在分子水平上给出目标元素周围的局部结构和化学信息的优势,能区分出与Fe,Al和Ca等金属结合的磷的形态.本文利用改进的Hedley连续提取法和XANES方法对贡嘎山海螺沟冰川退缩迹地上土壤中磷的形态进行了分析,在比较两种方法优缺点的基础上,获得了海螺沟冰川退缩120年序列上土壤磷的生物有效性的变化.结果表明:Hedley连续提取法对即时生物可利用磷能有准确的判识(Resin-P和NaCHO3-P),而XANES方法对金属结合态的磷有很好的判识.海螺沟冰川退缩时间序列土壤中钙铝结合态的磷主要为原生矿物磷,随成土作用增强而减少.即时生物可利用磷从30年后迅速增加,促使了植被形成和演替.
The bioavailability of soil phosphorus is an important factor affecting the safety and initial productivity of terrestrial ecosystems.The bioavailability of phosphorus in soils is determined by its morphological composition.The commonly used phosphorus morphological classification method is the continuous extraction method proposed by Hedley, Intensive extraction of soil samples by step-by-step extraction of extractants at all levels of phosphorus is defined as different forms of phosphorus in recent years has introduced the X-ray absorption near edge structure (XANES), the use of the molecular level to The advantage of the local structure and chemical information around the target element can distinguish the forms of phosphorus combined with metals such as Fe, Al and Ca, etc. In this paper, Hedley continuous extraction method and XANES method were used to study the retrogressive trace of the Hailuogou Glacier Based on the comparison of the advantages and disadvantages of the two methods, the change of bioavailability of soil phosphorus in the 120-year sequence of Hailuogou glacier retreat was obtained. The results showed that the Hedley continuous extraction method was more effective than the real- Available phosphorus can have accurate identification (Resin-P and NaCHO3-P), and XANES method for metal-bound phosphorus has a good sense of Hailuogou glacier withdrawal time series P soil calcium aluminum bound native minerals mainly phosphorus, with reduced formation of soil enhancement. Bioavailable immediate phosphorous rapidly increase from 30 years, and led to the formation of vegetation succession.