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| Responses of Karst soil anti-erodibility to different land use types |
| Li Hui1,2, Zhou Yunchao1,2,3, Liu Juan1, Li Ling1 |
| 1.College of Forestry, Guizhou University, 550025,Guiyang, China; 2.Research Center of Forest Resources and Environment in Guizhou Province, 550025, Guiyang, China; 3.Puding Karst Ecosystem Research Station of Guizhou Province, 562101, Puding, Guizhou, China |
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Abstract The objectives of this study were to understand the responses of soil anti-erodibility to the ways of land use in Karst region and to explore whether soil anti-erodibiliy methods used in loess plateau could be applied in Karst area. Six typical land use types in Karst region, i. e. , shrub-grass land, grazing shrub land, burned land, mixed vegetation, young forest, and sloping farmland in Chenqi catchment of Puding County, Guizhou Province, were used to test soil anti-erodibility indexes such as soil organic matter, soil bulk density, soil texture, micro-aggregate, aggregation degree, dispersion rate, dispersion coefficient, construction/ destruction rate, and water stable aggregate, and major influencing factors were analyzed. The three major indexes affecting soil anti-erodibility were content of soil organic matters, water stable aggregate (bigger than 0.5 mm) and anti-erodible index. Soil erodibility was in the order of shrubgrass land (2.00) > grazing shrub land (1.75) > burned land (0.71) > mixed vegetation (0.14) >young forest ( - 1.62) > sloping farmland ( - 2.99). Soil anti-erodibility changed with the ways and intensity of karst land use which affected plant cover and soil physical and chemical characteristics.Soil anti-erodibility was enhanced by positive human activities; however it was weakened if plant coverand soil structure were destroyed. Compared with the monitoring results from the entire slope of the large scale runoff site in Chenqi catchment, the order of soil anti-erodibility differed from that of soil erosion,and a lot of contradictory results existed among the studies of Karst region. The contradictions include:1) the chosen indexes were different among different researches; 2) some indexes repeatedly affected soil anti-erodibility; 3) some indexes affected soil anti-erodibility positively and also negatively; 4) many results in the soil anti-erodibility studies were inconsistent with our own experiences; 5) soil anti-erodibility was affected greatly by the characteristics of Karst thin soil, rocky desertification and gravels.Most of the indexes except for soil bulk density did not include the information of gravels. In this way, it is unreliable to simply copy soil anti-erodibility methods from loess plateau into the study of karst soil erodbility.
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Received: 24 November 2014
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