| 摘要: |
| 【目的】 分析3种针叶人工纯林发生土壤极化的风险。【方法】 2011-2012年，在黄土丘陵区，选择侧柏、油松和落叶松3种针叶人工纯林作为研究对象，分别测算了3种针叶人工林的林分生物量、生产力和养分循环量；此外，将采集的土壤分别与枯落物（枯落叶和根系）混合，进行分解培养试验，研究枯落物分解对土壤生物学性质的影响。【结果】 不同针叶人工纯林中，N、P、K积累量在不同器官中存在差异。侧柏纯林中，N、P、K主要积累在干中；落叶松纯林中，N、P、K主要积累在根和干中；在油松纯林中，N、P、K主要积累在根中。在生长季节短期内，侧柏和油松纯林的养分循环特征导致土壤存在K负向极化风险，落叶松纯林土壤存在N负向极化风险，而长期生长季节内3种纯林土壤都存在P负向极化风险。枯落物混土分解培养试验结果表明，侧柏和落叶松枯落叶分解会引起土壤多酚氧化酶活性发生负向极化，侧柏根系分解会引起土壤微生物数量、蔗糖酶和过氧化氢酶活性发生明显负向极化；油松枯落叶分解会引起土壤多酚氧化酶和过氧化氢酶活性发生负向极化。【结论】 侧柏和油松纯林土壤生物学性质发生负向极化的风险高于落叶松纯林；在生长季节应向侧柏和油松纯林土壤补充K肥，向落叶松纯林土壤补充N肥，并长期向3种纯林土壤补充P肥。 |
| 关键词: 土壤极化 针叶林 枯落物分解试验 养分循环 |
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| 基金项目:国家自然科学基金项目(31070630) |
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| Risk analysis of soil polarization due to nutrient cycling and litter decay in pure coniferous forests in the Loess Hilly Area |
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ZHANG Xiao-xi,LIU Zeng-wen,BING Yuan-hao,et al
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| Abstract: |
| 【Objective】This study aimed to analyze the risk of soil polarization in 3 kinds of artificial pure coniferous forests.【Method】3 kinds of artificial pure coniferous forests (Platycladus orientalis,Larix principis-rupprechtii and Pinus tabulaeformis) in the Loess Hilly Area were investigated,and the biomass,productivity,and nutrient cycling were measured.In addition,decay incubation experiments of different trees litters (leaf litters and roots) mixed with collected soils were carried out to investigate the effects of litter decomposition on soil biological properties.【Result】There were differences in the accumulation of N,P and K in different organs among the 3 tree species.N,P and K mainly accumulated in stem of P.orientalis,in root and stem of L.principis-rupprechtii,and in root of P.tabulaeformis.Because of the properties of nutrient cycling,there existed high risk of K negative polarization in soils of P.orientalis and P.tabulaeformis forests,and high risk of N negative polarization in soil of L.principis-rupprechtii forest in short growth-stage.While in long term,there existed high risk of P negative polarization in soils of all 3 forests in growth seasons.The mixed decomposition experiments showed that:decomposition of litters of P.orientalis and principis-rupprechtii would cause obvious negative polarization of polyphenoloxidase activity in soil;decomposition of root of P.orientalis would cause obvious negative polarization of microbes quantity,and sucrase and catalase activity in soil;decomposition of litter of P.tabulaeformis would cause obvious negative polarization of polyphenoloxidase and catalase activity in soil,and its root decay would cause obvious negative polarization of dehydrogenase activity in soil.【Conclusion】Risks of negative-biological soil polarization due to litters in P.orientalis and P.tabulaeformis forests were higher than in L.principis-rupprechtii forest.In growth stage,K should be added to soils of P.orientalis and P.tabulaeformis forests,and N should be added to soil of L.principis-rupprechtii forest.P should be added to soils of all the 3 forests in long term. |
| Key words: soil polarization coniferous forests litter decay experiment nutrient cycle |
