摘要：
为科学评估不同水土保持措施对石漠化地区的治理效果,进一步探索和完善石漠化地区水土流失治理工作,以云南沾益石漠化地区官麦地小流域为研究对象,分析水保林、坡耕地+巨菌草、坡改梯耕地和经果林等不同的水土保持措施对石漠化径流小区土壤改良和产流产沙的影响.结果表明:1)在相同降雨条件下,坡耕地产流量最多,水保林产流量最少.不同水土保持措施下,土壤侵蚀量由高到低分别为荒山草地、坡耕地、梯地、经果林和水保林,其土壤侵蚀量分别占总侵蚀量的65.00％、56.13％、52.43％、50.35％和46.03％;2)水保林、经果林、梯地和坡耕地可有效降低土壤密度、增大孔隙度以及改善土壤结构;3)治理后坡耕地土壤全氮全磷质量分数最高,经果林和水保林次之,荒山草地的全氮质量分数最低,坡耕地、经果林、水保林和梯地土壤全氮量分别较荒山草地高90.63％、74.48％、26.56％和22.4％,全磷质量分数分别较荒山草地高123.64％、96.36％、67.27％和16.64％.综合分析表明:水保林、坡耕地+巨菌草、坡改梯耕地、经果林等水土保持措施能减少水土流失,有效改善土壤理化性质;其中,水保林效果最好,经果林、梯地和坡耕地次之.该研究为解决西南地区石漠化问题,提供理论依据和技术支撑.%[Background] Karst rocky desertification is a process of land degradation involving serious soil erosion,extensive exposure of basement rocks,drastic decrease in soil productivity,and the appearance of a desert-like landscape.The process is expanding rapidly,and it is daily reducing the living space of residents and is the root of disasters and poverty in the Karst areas of southwestern China.Although some profitable experience has been conducted,scientific evaluations and effective remedial actions have not been carried out.[Methods] These experiments were conducted in Guanmaidi small watershed of Zhanyi County,Yunnan Province,where rocky desertification was severely suffered.We compared the difference of runoff and sediment yield characteristics after taking different measures in 5 runoff plots under different vegetation arrangements (soil and water conservation forest,economic fruit forest,slope farmland(Pennisetum sp.),terracing farmland,and wild grassland).[Results] 1) Under the condition of the same rainfall,soil and water conservation measures played a key role in reducing soil erosion.The flow of rain at slope farmland was the most while soil and water conservation forest was the least.Under different soil and water conservation measures,the descending order of soil erosion was as wild grass land,slope farmland (Pennisetum sp.),terracing farmland,economic fruit forest,and soil and water conservation forest.The amount of soil erosion in the total erosion amount were 65.00％,56.13％,52.43％,50.35％ and 46.03％,respectively.2) The measures of soil and water conservation improved the soil environment to a better condition.In soil and water conservation forest,economic fruit forest,terracing farmland,and slope farmland,soil bulk density decreased while soil porosity increased and soil structure was improved.3) The measures of soil and water conservation also improved the nutrient content of rocky desertified soil.The effect of slope tillage measure on improving soil total nitrogen and total phosphorus content was the highest,then the second for soil and water conservation forest and economic fruit forest,and the lowest for wild grassland.Specifically,the content of soil total nitrogen of slope farmland,economic fruit forest,soil and water conservation forest,terracing farmland increased by 90.63％,74.48％,26.56％,22.4％,and the soil total phosphorus of them increased by 123.64％,96.36％,67.27％,16.64％ compared with wild grassland.[Conclusions] In our data,soil and water conservation forest acts the best role in combating rocky desertification in this area,and then followings are economic fruit forest,slope farmland,terracing farmland.Our result provided a case study on combating rocky desertification in Southwest China,and helped to explore and improve the management of soil and water conservation in Karst area.Further study should be considered to combine soil and water conservation measures with industrial crops,such as using fruit tree forests or timber forests to combat rocky desertification in this area.Moreover,quantitative analysis of the pattern,process and evolutional mechanism of Karst rocky desertification will be the trend.
