典型喀斯特地区3种人工林对土壤理化和微生物特性的影响

Effects of three different plantations on soil physicochemical and microbial characteristics in Krast region

选择贵州省普定县典型喀斯特地区刺槐(Robinia pseudoacacia)纯林、滇柏(Cupressus duclouxiana)纯林、刺槐滇柏混交林(R.pseudoacacia-C.duclouxiana mixed plantation)及未造林地土壤为研究对象,通过野外采样和室内分析,测定了3种人工林对土壤理化与微生物生物量碳、氮、磷的影响。结果显示:刺槐滇柏混交林除全磷与滇柏林基本相同外,土壤有机碳、全氮、碱解氮、速效磷、含水量均高于刺槐林和滇柏林;土壤的p H各林分类型之间无显著差异;土壤密度从大到小依次为:滇柏林、未造林地、刺槐林、刺槐滇柏混交林。土壤微生物量碳以刺槐滇柏混交林最高(267.33 mg/kg),其余依次为滇柏林(163.34 mg/kg)、未造林地(125.62 mg/kg)及刺槐林(97.24 mg/kg)。土壤微生物量氮以刺槐滇柏混交林最高(38.45 mg/kg),其余依次为刺槐林(27.70 mg/kg)、未造林地(18.51 mg/kg)、滇柏林(14.81 mg/kg)。与微生物量碳、氮相似,微生物量磷仍以刺槐滇柏混交林最高,其余依次为滇柏林、刺槐林、未造林地。研究表明,在喀斯特地区刺槐滇柏混交林能够显著改善土壤养分和增加土壤微生物生物量碳、氮、磷的含量。

To study the effects of the different plantations on the soil microbial biomass carbon,nitrogen,phosphorus and physicochemical characteristics,three plantations [Robinia pseudoacacia plantation（ RP）,Cupressus duclouxiana plantation（ CD）,R. pseudoacacia- C. duclouxiana mixed plantation（ RC） ] and a non-plantation area（ CK） at the Karst regions were chosen as the research objects. The results showed that： Except the content of Total P,the contents of SOC,Total N,available N,available P and water of RC were higher than those of RP and CD. No differences were found among the soil p H of the three plantations. The soil bulk density was followed the order of CD,CK,RP,RC. The highest content of soil microbial biomass carbon was found in RC（ 267. 33 mg / kg）,followed by CD（ 163. 34 mg / kg）,the non-plantation area（ 125. 62 mg / kg） and RP（ 97. 24 mg / kg）. The highest content of soil microbial biomass nitrogen was RC（ 38. 45 mg / kg）,followed by RP（ 27. 70 mg / kg）,CK（ 18. 51 mg / kg） and CD（ 14. 81 mg / kg）. The highest content of soil microbial biomass phosphorus was still detected in RC,followed by CD,RP and CK. All of the results illustrated that RC could remarkably improve the soil nutrient and increase the microbial biomass carbon,nitrogen and phosphorus in the Karst regions.