石漠化生态恢复过程中土壤磷含量的比较研究

[目的]为了解桂西北石漠化地区生态恢复过程中磷含量的变化规律。[方法]选择平果、宜州等典型石漠化样地采样,分别对不同样地的土壤全磷及有效磷含量进行测定,并对全磷、有效磷含量与土壤中脲酶、过氧化氢酶活性及有机质含量的相关性进行分析。[结果]坡向、植被类型、恢复年限对土壤磷含量均有明显影响。表现为:南坡>北坡,任豆>封山育林>吊丝竹,随恢复年限的增加呈增加趋势。脲酶活性与磷含量变化有显著的相关性,可作为土壤肥力变化的监测指标。[结论]只要停止过度的人为干扰,桂西北石漠化地区的土壤会得到逐步的恢复,如果措施得当,采取人工促进的自然恢复手段,则会恢复到较好的水平。

Comparative Study on Phosphorus Contents of Soil in Karst Rocky Desertification Area during Eco-restoration Process

[Objective]The research aimed to study change law of phosphorus content of soil in karst rocky desertification(KRD) region during eco-restoration process in Northwest Guangxi Province.[Method] The soil samples were collected from typical KRD in Pingguo County and Yizhou City.The determining quotas of different soil samples such as soil total phosphorus content and available phosphorus content were detected,in addition the soil total phosphorus content,available phosphorus content,urease activity,catalase activity and organic matter content in different soil samples were analyzed comparatively.[Result] Aspect,vegetation type and recovery time generated obvious influences on phosphorus content in different soil samples.The concrete influence order was listed as follow: phosphorus content in soil of south slope was higher than that in soil of north slope;phosphorus content in soil where Zenia insignis was planted was higher than that in soil of closed forest and that of soil where Dendrocalamus minor was planted,additionally,phosphorus increased with recovery time.Urease activity could be used as a monitoring index of soil fertility because it is related to the change of phosphorus content.[Conclusion]The soil of karst rocky desertification region in Northwest Guangxi Province could be recovered gradually if excessive human disturbance was stopped.If proper natural method of recovery promoted by human was taken,the recovery would reach a better level.