喀斯特石漠化区治理措施对土壤质量演变的影响

为进一步探明喀斯特石漠化综合治理区不同治理措施对土壤质量演变的影响,选取3种治理措施:封山育林、人工造林和坡改梯,并以撂荒地为对照,通过长期定点监测,探索了治理措施与时间对土壤理化性质、土壤质量演变的影响特征。结果表明:治理措施和治理时间对土壤理化性质有明显的影响。封山育林、人工造林和坡改梯均能显著改善土壤理化性质,提高土壤肥力质量。随着时间的推移,土壤养分含量和土壤质量指数亦得到显著的改善。封山育林和人工造林对土壤质量的改善效果总体上优于坡改梯。此外,封山育林和人工造林能够明显优化土壤碳氮比例。但是这两种措施中土壤碳磷比(C/P)相对较高,且土壤碳磷比(C/P)随时间的推移逐渐增大,这反映出封山育林和人工造林的土壤面临土壤磷素缺乏的风险。石漠化综合治理措施中封山育林和人工造林对土壤质量的改善效果最佳。但是随着时间的推移,这两种措施可能会因土壤磷素缺乏导致植被恢复效果不佳。石漠化治理是一个漫长的过程,在其过程中需要通过人工干预以实现石漠化治理的可持续发展。

Effects of Control Measures on Soil Quality Evolution in the Karst Rocky Desertification Area in Southwestern China

The long-term stationary monitor was conducted to investigate the effects of different control measures on soil quality evolution in the karst rocky desertification areas.Three kinds of measures were selected:closed forest,artificial afforestation,and terracing,and the abandoned measure was taken as the control.The results showed that both of the measures and time had obvious effects on the soil physicochemical properties.The soil physicochemical properties and the soil quality fertility had been significantly improved by closed forest,artificial afforestation,and terracing.The effects of closed forest and artificial afforestation on soil quality were better than that of terracing.In addition,closed forest and artificial afforestation could significantly optimize the soil C/N.The soil C/P of these two measures was higher than that of terracing,and the soil C/P of closed forest and artificial afforestation increased with time,which reflected that closed forest and artificial afforestation suffered from the risk of soil phosphorus deficiency.Closed forest and artificial afforestation had better effect on improving soil quality.However,these two measures may lead to poor effect of vegetation restoration with the time due to the lack of soil phosphorus.Rocky desertification control is a long process,in which human intervention is needed to achieve sustainable development.