中文摘要：

[目的]研究典型喀斯特峰丛洼地系统土壤养分的空间分异特征，并探讨土地利用方式和地形因素对土壤养分的影响。[方法]采用网格和线形取样，利用经典统计方法，对土壤有机碳、全氮、全磷、全钾、碱解氮、速效磷、速效钾、pH值和C／N等进行了研究。[结果]土地利用方式是影响土壤有机碳、全氮、全磷、全钾、碱解氮、速效磷等养分含量的主要环境因子。其中有机碳、全氮、碱解氮含量随着土地利用强度的增加而降低。受施肥影响，耕地土壤的金磷和速效磷含量较高，全钾含量在各土地利用类型间则无明显差异；地形因子对有机碳、全氮、全磷、碱解氮、速效磷、速效钾和pH值有显着影响，其中立地因子对速效钾影响较大，高程因子对pH值影响较大。各因子对土壤C／N均没有显著影响。[结论]耕作对喀斯特脆弱生态系统土壤具有重要影响，是造成土壤养分流失、退化的主要原因。建议在喀斯特地区进行农业生产时应加强有机肥的施入。

英文摘要：

[Objective] In selecting a typical peak-cluster depression in karst region in Northwest Guangxi, we have evaluated the effects of land use and topographic factors on soil nutrients. [ Method ] Grid and line sampling methods were used to sample soils respectively, and classical statistical tools were applied to analyze the spatial variability characters of soil organic carbon （SOC）, total nitrogen （TN）, total phosphorus （TP）, total potassium （TK）, available nitrogen （AN）, available phosphorus （AP）, available potassium （AK）, pH, and C/N. [Result] Land use was the dominant factor that affected SOC, TN, TP, TK, AN and AP. SOC, TN, AN decreased with the increase of land-use intensity. Due to the difference of fertilizer input, TP and AP in tillage field were higher than the other land-use type. TK had no obvious change trend among various land-use types. Topographic factors had a significant effect on SOC, TN, TP, AN, AP, AK and pH. Habitat factor was the dominant factor that affected AK, and altitude factor was the dominant factor for pH. However, all of these factors had no significant effect on C/N. [ Conclusion ] Tillage practice had important effect on soil nutrients loss and soil degradation in the fragile karst ecosystem. An increased input of organic manure in this region is recommended.