桂西北喀斯特人为干扰区植被自然恢复与土壤养分变化

为促进桂西北喀斯特退化生态系统的恢复与重建,采用全面调查和样方调查方法,以自然保护区的顶级群落为对照,研究了桂西北喀斯特人为干扰区自然恢复22a后植被的演替规律与土壤养分变化。结果表明,干扰区物种丧失严重,种类仅有自然保护区的26.6%,随着群落由草丛→草灌丛→灌丛→藤刺灌丛→乔灌丛→顶级群落的顺向演替和发展,群落的高度、生物量和物种多样性、土壤有机质、养分、阳离子交换量和硅、铁、铝、钛等矿质全量逐步增加,钙、镁全量显著减少,pH值降低,土壤质量随着植被的恢复呈波折性提高。

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