Changes of Soil Nutrients in Process of Natural Vegetation Restoration in Karst Disturbed Area in Northwest Guangxi

WU Hai-yong1,2,3,PENG Wan-xia1,3,4,SONG Tong-qing1,3,ZENG Fu-ping1,3,LI Xing-hui1,2,SONG Xi-juan1,3,5,OUYANG Zi-wen1,3,4(1.Institute of Subtropical Agriculture,Chinese Academy of Sciences,Changsha 410125;2.Tea Institute,Nanjing Agricultural University,Nanjing 210095;3.Station of Karst Ecology in Huanjiang,Institute of Subtropical Agriculture,CAS,Huanjiang 547200;4.College of Bioscience and Biotechnology,Hunan Agricultural University,Changsha 410128;5.Pratacultural College,Gansu Agricultural University,Lanzhou 730070)

disturbed area;natural vegetation restoration;soil nutrient;karst region in northwest Guangxi

The successional rule of vegetation and dynamics of soil nutrient elements after 22-years' natural restoration were studied in karst disturbed area in northwest Guangxi,which would promote the degraded ecosystem restoration and reconstruction in northwest Guangxi.The study was employed overall and sample quadrate investigation method and taken the climax community in Mulun Natural Reserve in Huanjiang County as control.The results showed that the diversity lost severely in the disturbed area with only 26.6% species of that in Mulun Natural Reserve.With the succession and development from grass,grass and bushes,bushes,liana and bushes,trees and bushes to the climax community,the community heighty,biomass,plant diversity,soil organic carbon,soil nutrient,cation exchange capacity(CEC),and the content of Si,Fe,Al,and Ti increased gradually.However,the content of Ca and Mg reduced remarkably,the value of pH decreased.All this indicated that the soil quality improved with the vegetation recovery basically but with slight drop in the stage of liana and bushes.