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林业科学 ›› 2019, Vol. 55 ›› Issue (4): 22-30.doi: 10.11707/j.1001-7488.20190403

• 论文与研究报告 • 上一篇    下一篇

三峡库区消落带土壤化学性质年际变化特征

郭燕1,2, 程瑞梅1,2, 肖文发1,2, 沈雅飞1,2, 杨邵1,2, 王娜1,2, 刘泽彬1,2, 王晓荣1,3   

  1. 1. 中国林业科学研究院森林生态环境与保护研究所 国家林业和草原局森林生态环境重点实验室 北京 100091;
    2. 南京林业大学南方现代林业协同创新中心 南京 210037;
    3. 湖北林业科学研究院 武汉 430075
  • 收稿日期:2017-08-03 修回日期:2019-03-05 出版日期:2019-04-25 发布日期:2019-04-30
  • 基金资助:
    中国林业科学研究院基本科研业务费专项(CAFYBB2017ZA002);‘十三五’国家重点研发计划(2017YFC050530402)。

Inter-Aannual Variation of Soil Chemical Properties in the Water-Level-Fluctuation Zone of the Three Gorges Reservoir

Guo Yan1,2, Cheng Ruimei1,2, Xiao Wenfa1,2, Shen Yafei1,2, Yang Shao1,2, Wang Na1,2, Liu Zebin1,2, Wang Xiaorong1,3   

  1. 1. Key Laboratory of Forest Ecology and Environment, National Forestry and Grassland Administration Research Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry Beijing 100091;
    2. Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University Nanjing 210037;
    3. Hubei Forestry Academy Wuhan 430075
  • Received:2017-08-03 Revised:2019-03-05 Online:2019-04-25 Published:2019-04-30

摘要: [目的]分析三峡库区消落带经历长期水库水位变化后的土壤化学性质,为揭示消落带水文环境变化提供科学依据。[方法]在秭归段消落带回水区选择典型次生灌丛固定监测样地,根据库区水位运行计划,于2008、2009、2012、2014和2015年(分别经历0、1、4、6和7次水位涨落)对不同海拔(145~155、155~165、165~175、175~185 m)样地的不同土层(0~10和10~20 cm)土壤的pH值和有机质及碱解氮、速效磷和速效钾含量进行测定。[结果]经历7次水位涨落后,所有海拔的pH值均明显增加,其中海拔145~155 m土壤由酸性(pH6.1)变为碱性(pH8.2),而其他海拔土壤逐渐由酸性趋于中性;水淹海拔区土壤有机质含量高于非水淹对照海拔(175~185 m),且随水淹时间增加,0~10 cm土层有机质含量较2008年呈逐年下降趋势,而10~20 cm土层则先增加后降低;随水位涨落周期的增加,土壤碱解氮含量呈波动性下降趋势,且0~10 cm土层土壤对水淹影响更为敏感,0~10 cm土层碱解氮以2009年和2015年下降最为显著(P<0.05),和2008年相比各海拔降幅分别达37.2%~54.7%和50.6%~65.7%;0~10 cm土层速效钾含量在2009年降幅最大,达17.1%~50.8%;速效磷含量则呈逐年下降趋势,且在速效养分中的流失量最大,在经历4、6和7次水位涨落后,速效磷含量较2008年分别下降78.0%、94.8%、91.6%(0~10 cm)和89.5%、93.6、92.5%(10~20 cm)。[结论]随三峡水库运行周期的不断延长,消落带土壤pH值升高、有机质含量下降,消落带土壤养分匮乏现象将突显,对于消落带经历长期水位涨落后的土壤化学性质变化仍需长期监督。

关键词: 消落带, 次生灌丛, 水位涨落, 土壤pH值, 土壤有机质, 土壤速效养分, 年际变化

Abstract: [Objective]Chemical properties of soils at different altitudes and layers after long-term reservoir water level changes were analyzed to understand the degree of variation of soil environment after years of drastic changes in dry-wet alternation in the fluctuation zone of the Three Gorges Reservoir.[Method] Sample plots were set up in a secondary shrub forest within the typical hydro-fluctuation belt in the Three Gorges Reservoir. According to the water level operation plan of the reservoir area, the pH-value, organic matter, and contents of available N, available P and available K in the soil at different altitudes (145-155, 155-165, 165-175, and 175-185 m) in different soil layers (0-10 and 10-20 cm) were measured in 2008, 2009, 2012, 2014, and 2015 (that is, through 0, 1, 4, 6, and 7 fluctuations of water level, respectively).[Results]Results showed that soil pH-values at all altitudes increased obviously, the pH value at 145-155 m changed from acid (pH6.1) to alkaline (pH8.2), and the pH-values at other altitudes gradually tended to be neutral after 7 fluctuations of water level. The extent of pH variation at different altitudes was:145-155 m > 155-165 m > 165-175 m > 175-185 m. The content of soil organic matter in the flooded area was higher than that of the non-flooded area at 175-185 m. With the increase of flood duration, the content of organic matter in the 0-10 cm soil layer decreased year by year compared with that in 2008, but in the 10-20 cm soil layer it increased first and followed by a decrease. With the increase of the number cycles of water level fluctuation, the contents of soil alkali hydrolysable nitrogen and available potassium showed a downward trend of fluctuation, and the contents in the 0-10 cm soil layer were more sensitive to flooding compared with those in 10-20 cm layer. The alkali hydrolyzed nitrogen in 0-10 cm soil layer decreased most significantly in 2009 and 2015, and compared with 2008, the decrease at all altitudes was by 37.2%-54.7% and 50.6%-65.7%, respectively. Moreover, the decrease of available potassium in 0-10 cm soil layer was the largest in 2009, up to 17.1%-50.8%. The content of available P decreased year by year, and the loss of available P was the biggest among all the available nutrients. After 1, 4, 6 and 7 fluctuations of water level, the content of available phosphorus in 0-10 cm layer significantly decreased by 21.8%, 45.4%, 82.2%, and 90.2%, and the content of available phosphorus in 10-20 cm layer significantly (P<0.01) decreased by 44.3%, 61.5%, 83.5%, and 92%, respectively.[Conclusion]With continual extension of the operation period of the Three Gorges reservoir, the soil properties of the fluctuating zone change gradually, reflected by the increased soil pH-values, the decreased content of organic matter, and the depleted available nutrients. To a certain extent, this provides a new scientific basis for predicting succession process of ecological environment quality and the changes of soil properties in the reservoir area under long-term flooding conditions.

Key words: water-level-fluctuation zone, secondary shrub, annual fluctuation of water level, soil pH, soil organic matter, soil available nutrients, inter-annual variability

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