典型岩溶区植被恢复对土壤养分的影响

Eeefects of Vegetation Restoration on Soil Nutrient in Typical Karst Area

对典型岩溶地区不同植被恢复(草丛、灌草丛、灌丛、乔幼林和成熟林)过程中的土壤养分进行研究,结果表明:土壤养分随着植被的恢复呈波折状上升,但是各恢复阶段过程中的土壤有机质、有效N、P、K、有效Zn、Cu、Mn、Fe含量存在无显著性差异(P>0.05),弃耕后2～3年的草丛土壤养分含量可以达到成熟林的养分水平;土壤pH值与有机质、有效N、P、K、有效Zn、Cu、Mn、Fe含量存在不同程度的负相关关系,降低土壤的pH值,可以有效的提高石灰土肥力;土壤养分具有明显的表聚性。在岩溶区,退耕还草、退耕还林、种植牧草和自然恢复是石漠化地区较好的生态重建和植被恢复方式。

Understanding the relationship between plant community succession and soil nutrient dynamics is crucial in intervening vegetation restoration. This paper reported the results from a study carried out in a typical karst area , Guangxi, China, with em- phasis on soil nutrient dynamics during vegetation restoration on abandoned farmlands of this area. The results showed that ： soil fertility improved with the vegetation recovery basically but with slight drop in some stage in different nutrient,but no sig- nificant differences were observed in soil organic matter, available N, P, K. available Zn, Cu, Mn, Fe under each vegetation stage. That is mean, grass soll nutrient which has abandoned two or three years can reach the nutrient level in mature forest soil. There was a negative correlation between pH and organic matter, available N, P, K. available Zn, Cu, Mn, Fe. so falling down soil pH is an effective measure to improve soil fertility, soil nutrient centralize on the surface. Turning farmlands to grass and forest, planting grass, natural restoration should be the optional choices to restore vegetation and ecological rebuilding in rock desertification area.