| 三峡库区澎溪河不同高程消落带土壤磷形态及磷酸酶活性分布特征 |
| 摘要点击 1529 全文点击 409 投稿时间：2021-11-01 修订日期：2022-02-22 |
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| 中文关键词 三峡库区 消落带土壤 高程 磷形态 磷酸酶活性 |
| 英文关键词 Three Gorges Reservoir soils of water-level-fluctuation zone(WLFZ) altitude phosphorus form phosphatase activity |
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| 中文摘要 |
| 磷酸酶可将有机磷矿化为无机磷，对土壤有机磷转化具有重要作用，然而目前鲜见关于三峡库区消落带土壤磷酸酶及其与磷形态转化的相关报道.研究澎溪河流域落干期不同高程消落带土壤磷形态及磷酸酶活性的分布特征，分析了磷酸酶活性与磷形态之间的相关性及其对磷形态的影响.结果表明，不同高程消落带土壤的H2 O-Pi、NaHCO3-Pi和NaOH-Pi含量均高于岸边土壤，生物可酶解磷含量和NaOH-Po含量随高程增加而升高.冗余分析显示有机质和无定形铁锰含量是影响不同高程土壤有机磷形态的主要原因.消落带土壤酸性磷酸酶、碱性磷酸酶、磷酸二酯酶（以p-NP计）和植酸酶（以P计）活性均值分别为1.40、2.60、0.44和11.43 μmol ·（g ·h）-1，且消落带土壤各磷酸酶活性随高程增加而增大，植物量和微生物量差异是导致消落带磷酸酶活性空间分布差异的重要原因.整体上消落带土壤磷酸酶活性与各有机磷形态含量呈显著正相关，而与生物可利用磷含量呈负相关.较高高程消落带土壤磷酸酶活性较高而生物可利用磷含量较低，在淹水初期磷酸酶介导的矿化有机磷为无机磷速率相对较高，向上覆水体释放磷的风险也较大.研究成果有助于全面理解三峡库区消落带土壤磷的地球化学循环. |
| 英文摘要 |
| Phosphatases play important roles in converting organic phosphorus into inorganic phosphorus in soil. However, studies from this perspective on the water-level-fluctuation zone (WLFZ) of the Three Gorges Reservoir are limited. In this study, phosphatase activity and the forms of phosphorus were analyzed. Soil samples were collected in the river basin of the Penxi River in the WLFZ during a drying period. The correlation between phosphatase activity and phosphorus forms and the impacts of phosphatase activity on the phosphorus forms were analyzed. The results showed that the contents of H2O-Pi, NaHCO3-Pi, and NaOH-Pi in the soils of the WLFZ were higher than those in the soils by the river. In addition, a higher altitude resulted in higher contents of bio-enzymatically hydrolysable phosphorus and NaOH-Po. Furthermore, redundancy analysis (RDA) showed that the contents of organic matter and amorphous Fe and Mn were the main factors affecting soil organic phosphorus forms. The average activities of acid phosphomonoesterase (ACP), alkaline phosphomonoesterase (ALP), phosphodiesterase (PDE) (all in p-NP), and phytase (PAE) (in P) in the soils of the WLFZ were 1.40, 2.60, 0.44, and 11.43 μmol·(g·h)-1, respectively. Moreover, the activities of different phosphatases increased with altitude. Soil plant biomass and microbial biomass were important reasons for the difference in spatial distribution of phosphatase activity in the soil of the WLFZ. Phosphatase activities were significantly positively correlated with the contents of organic phosphorus forms but negatively correlated with the content of bioavailable phosphorus. A higher soil phosphatase activity and a lower content of bioavailable phosphorus were usually detected in soil samples taken at a higher altitude. In the early stage of flooding, phosphatase converted organic phosphorus into inorganic phosphorus at a relatively high rate, and the risk of phosphorus release to the overlying water body was also high. This study contributed to a comprehensive understanding of the geochemical cycle of soil phosphorus in the soil of the WLFZ. |
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