[1]YU Guojun,XIE Xiaoyao.Effects of Afforestation on Soil Aggregate Stability and Microbial Carbon Metabolism Activity in Karst Area[J].Research of Soil and Water Conservation,2020,27(06):21-27,36.
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Research of Soil and Water Conservation[ISSN 1005-3409/CN 61-1272/P] Volume:
27
Number of periods:
2020 06
Page number:
21-27,36
Column:
目次
Public date:
2020-10-20
- Title:
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Effects of Afforestation on Soil Aggregate Stability and Microbial Carbon Metabolism Activity in Karst Area
- Author(s):
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YU Guojun1, XIE Xiaoyao2
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(1.School of Computer Science and Technology, Guizhou University, Guiyang 550001, China; 2.Key Laboratory of Information and Computing Science, Guizhou Normal University, Guiyang 550001, China)
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- Keywords:
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karst regions; afforestation; soil aggregates; soil microorganism
- CLC:
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S714
- DOI:
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- Abstract:
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Soil aggregates play an important role in soil fertility, quality and sustainable utilization.(0—10, 10—20, 20—30 cm)large soil aggregate(>2 mm), intermediate aggregate(0.25~2 mm), micro aggregate(53 μm~0.25 mm)and glue powder+aggregate(<53 μm)mass fraction in different soil layers of different planting areas(Alnus cremastogyne, Eucommia ulmoides, Robinia pseudoacacia, Cipressus duclouxiana forest and not planting area, CK)were obtained by wet sieving method, and soil microbial biomass and microbial activity of carbon metabolism were measured. The results showed that afforestation had a significant impact on the stability of soil aggregates, and the fragmentation of large aggregates was caused by afforestation, and the contents of >0.25 mm large aggregates in unforested areas were lower than those in forested areas, indicating that the soil structure tended to be improved after afforestation; in the soil depth of 0—30 cm, >0.25 mm large aggregates in the Alnus cremastogyne forest and Eucommia ulmoides forest are dominated and accounted for more than 20% of the total aggregates; intermediate aggregates and powder+sticky aggregates in Eucommia ulmoides and Cipressus duclouxiana were main components of the aggreates; however, the powder+cohesive aggregates in unused woodlands were of dominant, accounting for about 40% of the aggregates; in the depth of 0—30 cm, the MWD and GMD values of aggregates in Alnus cremastogyne and Eucommia ulmoides forest were significantly higher than those of other woodlands, while in the depth of 20—30 cm, the differences were smaller, indicating that the influence of human activities on the stability of soil aggregates mainly concentrated in the surface layer of 0—10 cm; the utilization intensities of different types of carbon sources by soil microorganisms in different woodlands were quite different; carbon sources of carbohydrates and carboxylic acids were the main carbon sources of soil microorganisms, followed by amino acids, phenolic acids and polymers, and amine carbon sources had the lowest utilization rate. Correlation analysis showed that amino acids, carbohydrates and carboxylic acids were significantly positively correlated with macroaggregates, mesocarbons, MWD and GMD during afforestation (p<0.05). Microbial biomass carbon, microbial biomass nitrogen and microbial metabolic entropy were positively correlated with microaggregates and powder microaggregates (p<0.05). In summary, soil structure tended to be improved after afforestation in karst areas, and the activity of microbial carbon metabolism was enhanced.