花岗岩红壤侵蚀退化地植被恢复措施的水土保持调控效应OA

[Objective]To investigate the effects of different vegetation restoration measures on improving soil physicochemical properties and soil-water conservation characteristics in granite red soil erosion-degraded areas of southern China,evaluate their comprehensive regulatory benefits,and identify optimal restoration measures.[Methods]The study selected five vegetation restoration measures in Changting County,Fujian Province:replanting broadleaf tree+fish scale pit(Z1),grass-shrub-arbor mixture(Z2),replanting broadleaf tree+strip ditch sowing grass(Z3),dense-hole grass sowing(Z4),and contour grass filling belt(Z5),with Pinus massoniana forest(CK)as the control.Differences in soil physicochemical properties among treatments were analyzed,and a comprehensive assessment of soil quality and slope runoff-sediment reduction benefits was conducted for each measure.[Results]1)All vegetation restoration measures significantly improved soil physicochemical properties.Compared with CK,they increased volumetric water content,porosity,and mean weight diameter(MWD)by 16.91%-37.97%,4.56%-22.81%,and 25.68%-59.62%,respectively,while reducing bulk density,disintegration coefficient,and erodibility K value by 3.74%-18.69%,32.85%-63.41%,and 10.35%-17.27%,respectively.2)Soil organic carbon,total nitrogen,total phosphorus,available phosphorus,and available potassium contents increased by 129.49%-321.46%,89.47%-137.99%,22.70%-78.09%,118.08%-190.88%,and 3.88%-166.01%compared to CK,respectively,exhibiting significant surface layer accumulation effects.However,no obvious pattern was observed in the variation of total potassium content.3)Soil Quality Index(SQI)evaluation showed the following order:Z1(0.746)>Z3(0.717)>Z2(0.697)>Z5(0.552)>Z4(0.551)>CK(0.280).4)The vegetation restoration measures exhibited significant runoff reduction(27.93%-39.02%)and sediment reduction benefits(75.86%-82.87%),among which the Z3 measure demonstrated the optimal effect.[Conclusion]All vegetation restoration measures improved soil physicochemical properties,enhanced overall soil quality,and effectively reduced surface runoff and slope sediment loss.Comprehensive assessment demonstrated that the Z3 measure delivered the best performance in soil improvement and soil-water conservation,followed by Z1 and Z2.The research findings provide guidance for the optimal allocation of soil-water conservation measures in red soil erosion-degraded areas and offer a scientific basis for formulating and implementing soil erosion prevention strategies.