Soil aggregation and aggregate-associated carbon under four typical halophyte communities in an arid area

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• 作者：Haichang Yang ; Jingya Wang ; Fenghua Zhang
• 关键词：Soil aggregate ; Soil organic C ; Soil microbial biomass C ; Halophyte community ; Arid region
• 刊名：Environmental Science and Pollution Research
• 出版年：2016
• 出版时间：December 2016
• 年：2016
• 卷：23
• 期：23
• 页码：23920-23929
• 全文大小：733 KB
• 刊物类别：Earth and Environmental Science
• 刊物主题：Environment
  Environment
  Atmospheric Protection, Air Quality Control and Air Pollution
  Waste Water Technology, Water Pollution Control, Water Management and Aquatic Pollution
  Industrial Pollution Prevention
  
• 出版者：Springer Berlin / Heidelberg
• ISSN：1614-7499
• 卷排序：23

文摘

The soil microbial biomass carbon (MBC) is considered as a sensitive index of soil carbon ecosystem. The distribution of aggregate-associated MBC determines the capacity of the soil to store soil organic carbon (SOC). We compared soil aggregate-associated SOC and aggregate-associated MBC under four halophyte communities: Karelinia caspia (Pall.) Less. (Abbr. K. caspia), Bassia dasyphylla (Fisch. et C. A. Mey.) Kuntze. (Abbr. B. dasyphylla), Haloxylon ammodendron (C. A. Mey.) Bunge. (Abbr. H. ammodendron), and Tamarix ramosissima Lour (Abbr. T. ramosissima) on an alluvial fan in the Manasi River Basin, Xinjiang, China. The specific objectives of the study were to determine which aggregate size fraction was the most important for MBC and SOC retention in these soils of four halophyte communities. The results showed that the 0.053–0.25 mm fraction contained 47 to 75 % of the total soil mass. The amount of soil in the 0.053–0.25 mm fraction was significantly greater than that in the >0.25 and the <0.053 mm fractions. The >0.25 and the <0.053 mm fractions contained 7.8 to 43.0 % of the soil mass. Aggregate-associated SOC concentrations ranged from 1.70 to 13.68 g kg−1, and the aggregate-associated SOC were the highest under the H. ammodendron and T. ramosissima communities. The aggregate-associated MBC ranged from 55.26 to 217.11 g kg−1, and the aggregate-associated MBC were higher under the K. caspia and B. dasyphylla communities. The aggregate-associated SOC concentrations were significantly higher in the >0.25 and the <0.053 mm fractions than in the 0.053–0.25 mm fraction. The aggregate-associated MBC in the 20–40 cm depth was consistent with its law. However, in the 0–20 cm depth, the aggregate-associated MBC concentrations were significantly higher in the >0.25 mm fraction than the other two aggregate fractions, and there were no significant differences in 0.25–0.053 or <0.053 mm fraction. Correlation analyses showed that the aggregate-associated MBC positively correlated with aggregate-associated SOC in >0.25 mm fraction (P < 0.01). The microbial entropies ranged from 1.12 to 4.17 %, and the microbial entropy generally was higher in >0.25 mm fraction. Overall, the H. ammodendron community had the higher aggregate-associated SOC and aggregate-associated MBC, but the microbial entropy was low. This suggested that among the four halophyte communities in this study, the H. ammodendron community could be beneficial for soil carbon storage in arid regions.