| 摘要: |
| 对6个不同封育年限的天然次生油松林林地土壤肥力和酶含量进行了分析。结果表明,对于同一封育年限的油松林地,土壤有机质、硝态氮、速效磷和脲酶含量随采样深度增加而减小;在封育的前30年,林地表层土壤有机质含量随封育年限增加而减小,硝态氮、氨态氮和脲酶含量随封育年限增加表现出先减小后增大的趋势,速效钾、速效磷和过氧化氢酶含量表现出先增大后减小的趋势;封育30年后,林地表层土壤有机质和速效钾含量随封育年限增加而增加,硝态氮、氨态氮、速效磷和过氧化氢酶含量随封育年限增加表现出先增大后减小的趋势,脲酶含量则表现出先减小后增大的趋势。主成分分析结果表明,随着封育年限的增加,土壤综合因子值总体有下降的特征,为了加速有机质分解,提高林地肥力水平,对封育30年后的林分应进行卫生伐和择伐。 |
| 关键词: 油松 封育 土壤养分 酶活性 主成分分析 |
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| 基金项目:国家科技攻关计划重大专项专题项目（2002BA516A15-05）；西北农林科技大学青年基金项目（QN-2003-07） |
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| Study on soil nutrient and enzyme in hillclosed and afforested natural secondary Pinus tabulaeformis forest land in Huanglong mountain |
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| Abstract: |
| Soil nutrient and enzyme contents of natural secondary Pinus tabulaeformis forest land among 6 hill closed and afforested(H & A) ages were analyzed.The results show that in the same H & A,with depth of soil increasing,contents of organic matter(OM),NO-3-N,available phosphor(AP) and urease decreased respectively.During 30 years before H & A,in the depth of 0 to 20 cm of soil,with the increase of H & A,OM decreased continuously.Meanwhile,contents of NO-3-N,NH+4-N and urease demonstrated a trend from increase to decrease.However,contents of available potassium(AK),AP and CAT indicated a reversed trend.Furthermore,30 years after H & A,with the increase of H & A,contents of OM and AK increased continuously.In the same time,contents of NO-3-N,NH+4-N,AP and CAT showed a trend increase to decrease.On the contrary,content of urease took on a reversed trend.Based on principle components analysis,values of soil comprehensive factor decreased.For the purpose to improve whole level of nutrient in Pinus tabulaeformis forest land,selective cut should be carried out 30 years after H & A. |
| Key words: Pinus tabulaeformis,hill closed and afforested,soil nutrient,enzyme activity,principle components analysis |
