[1]Wang Ping,Ding Zhiqiang,Li Lushan,et al.Stability and Mechanisms of Soil Aggregates in Major Forest Types in Central Yunnan[J].Research of Soil and Water Conservation,2024,31(05):232-242.[doi:10.13869/j.cnki.rswc.2024.05.007]
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Research of Soil and Water Conservation[ISSN 1005-3409/CN 61-1272/P] Volume:
31
Number of periods:
2024 05
Page number:
232-242
Column:
Public date:
2024-08-10
- Title:
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Stability and Mechanisms of Soil Aggregates in Major Forest Types in Central Yunnan
- Author(s):
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Wang Ping1, Ding Zhiqiang1,2,3, Li Lushan4, Li Yuhui1
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(1.Department of Geography, Yunnan Normal University, Kunming 650500, China; 2.School of Geographical Sciences, Fujian Normal University, Fuzhou 350007, China; 3.Fujian Sanming Forest Ecosystem National Observation and Research Station, Sanming, Fujian 365002, China; 4.Zixi Middle School Chuxiong, Yunnan Province, Chuxiong, Yunnan 675099, China)
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- Keywords:
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soil aggregates; stability; impact factors; forest types; central Yunnan region
- CLC:
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S157.5
- DOI:
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10.13869/j.cnki.rswc.2024.05.007
- Abstract:
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[Objective]Aggregated stability is an important indicator for assessing changes in soil quality after vegetation restoration in degraded ecosystem. The aims of this study are to investigate the difference of soil aggregate stability and its change mechanism of main forest types in central Yunnan, and to provide scientific support for tree species selection and forest resource scientific management in the process of vegetation restoration and transformation in the future. [Methods]Six primary forest types, including Pinus yunnanensis forest(PY), Pinus armandii forest(PA), Acacia dealbata forest(AD)and Alnus cremastogyne forest(ACF), Theropencedrymion forest(TF), and Secondary evergreen broad-leaved forest(SF), were selected for the study. Dry slope land(DSL)was used as a control. Soil samples were collected from depths of 0—20 cm, 20—40 cm, and 40—60 cm. Dry sieving and wet sieving methods were employed to classify aggregates into four size classes:>5 mm, 5~2 mm, 2~0.25 mm and<0.25 mm. Four stability indices, including WR>0.25, mean weight diameter(MWD), geometric mean diameter(GMD)and structural failure rate(PAD), were calculated to investigate soil aggregate stability. [Results](1)Among the six forest types, aggregates with a particle size range of 0.25~2 mm predominated in the 0—60 cm soil layers, while DSL shifted from 0.25~2 mm to<0.25 mm with increasing soil depth.(2)In the 0—60 cm soil layer, WR>0.25, MWD, GMD, and PAD values in DSL were 55.40%, 1.16 mm, 0.52 mm, and 40.47%, respectively. The six forest types exhibited aggregate stability ranging from 71.61% to 78.20% for WR>0.25, 1.97 mm to 2.61 mm for MWD, 0.93 mm to 1.27 mm for GMD, and 12.59% to 20.47% for PAD. Overall, DSL exhibited the poorest aggregate stability, followed by SF and TF, while PY, ACF, AD, and PA showed relatively lower stability.(3)At the macro scale, soil aggregate stability in the study area was significantly influenced by forest type, soil depth, and their interaction(p<0.001). At the micro scale, it was mainly affected by soil bulk density, non-capillary porosity, total potassium, soil organic matter, sand content, and clay content(p<0.05). Soil physicochemical properties, nutrients, and texture explained 90.5% of aggregate stability, with the greatest contribution coming from the interaction of physicochemical properties and nutrients, accounting for 61.3%. Soil texture often interacted with other factors to influence aggregate stability, with an independent explanatory power of only 5.1%. [Conclusion]In central Yunnan, the stability of soil aggregates can be significantly improved by returning farmland to forest. Future ecological restoration should focus on creating Pinus yunnanensis and Alnus cremastogyne forest, while avoiding high-intensity human activities, improving soil physical and chemical properties and increasing soil nutrient accumulation, and promoting the evolution of artificial pure forest into theropencedrymion forest and secondary forest.