贡嘎山燕子沟土壤磷海拔梯度特征及影响因素

发布时间：2018-05-05 23:39

  本文选题：生物有效磷 + 磷形态　； 参考：《山地学报》2016年04期

【摘要】：土壤磷生物地球化学特征受岩性、气候、土壤年龄、理化性质、地形、植物和微生物活动等因素的共同影响。山地植被和土壤垂直带谱为研究这些因素的相对重要性提供了理想试验场。选取未受人类破坏的贡嘎山燕子沟5个垂直植被带(裸地、高山灌丛带、暗针叶林带、针阔混交林带和阔叶林带,海拔分别为3 761 m、3 600 m、3 403 m、2 700 m和2 334 m),采集了40个土样,测定了土壤的基本理化性质,并采用连续提取法测定了土壤的生物有效磷、铝结合态磷、铁结合态磷、原生矿物磷、有机磷和残余态磷。结果表明,燕子沟土壤A层部分磷形态的空间分布呈现明显的垂直地带性特征。土壤A层的原生矿物磷随海拔的降低而显著降低,有机磷则呈现与原生矿物磷相反的变化趋势。而生物有效磷始终较低,次生矿物磷(铝和铁结合态磷)也较低,残余态磷的含量变化不大,始终是土壤总磷的最大组分。在高海拔地区原生矿物磷是总磷的第二大组分,而在低海拔地区,有机磷则成为总磷的第二大组分。植物是控制燕子沟土壤磷空间分布的相对重要因素,植物一方面通过控制土壤p H进而影响土壤原生矿物磷的含量,另一方面直接吸收生物有效磷,并将其转化为有机磷,导致有机磷随海拔降低而显著增加。此外,植物还通过"泵吸作用"导致总磷在土壤剖面上呈现由表层向底层降低的分布模式。次生矿物磷含量较低表明地球化学作用在影响燕子沟土壤磷生物有效性的作用相对较小。
[Abstract]:The biogeochemical characteristics of soil phosphorus are influenced by lithology, climate, soil age, physical and chemical properties, topography, plant and microbial activities. Mountain vegetation and soil vertical band spectrum provide an ideal test ground for studying the relative importance of these factors. Five vertical vegetation zones (bare land, alpine shrub belt, dark coniferous forest belt, coniferous and broadleaved forest belt) in the Yanzigou, Gongga Mountain, were selected and their elevation was 3 761 m ~ 3 600 m ~ 3 403 m ~ (2 700 m) and 2 334 m ~ (-1), respectively, and 40 soil samples were collected. The basic physical and chemical properties of the soil were determined, and the bioavailable phosphorus, aluminum bound phosphorus, iron bound phosphorus, primary mineral phosphorus, organic phosphorus and residual phosphorus were determined by continuous extraction method. The results showed that the spatial distribution of phosphorus forms in A layer of Yanzigou soil showed obvious vertical zonal characteristics. The primary mineral phosphorus of the A layer of soil decreased significantly with the decrease of altitude, while the organic phosphorus showed a trend opposite to that of the primary mineral phosphorus. But the bioavailable phosphorus was always low, the secondary mineral phosphorus (aluminum and iron bound phosphorus) was lower, the content of residual phosphorus changed little, and was always the largest component of total phosphorus in soil. Phosphorus is the second major component of total phosphorus in high altitude area, and organic phosphorus is the second largest component in low altitude area. Plant is a relative important factor to control the spatial distribution of phosphorus in Yanzigou soil. On the one hand, the plant controls soil pH and then affects the content of soil primary mineral phosphorus, on the other hand, it directly absorbs bioavailable phosphorus and converts it into organic phosphorus. As a result, organophosphorus increased significantly with the decrease of altitude. In addition, the distribution pattern of total phosphorus in soil profile was reduced from the surface to the bottom. The low phosphorus content of secondary minerals indicates that geochemical action has a relatively small effect on the bioavailability of phosphorus in Yanzigou soil.
【作者单位】： 中国科学院山地表生过程与生态调控重点实验室/中国科学院水利部成都山地灾害与环境研究所;
【基金】：国家自然科学基金项目(41401253和41272200)资助~~
【分类号】：S153
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本文编号：1849754