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以空间代替时间的方法,对川西亚高山天然针叶林、桦木次生林、人工云杉林有机层和矿质层土壤碳、氮、磷化学计量以及土壤微生物生物量和呼吸进行比较分析.结果表明,天然针叶林转化为次生林和人工林,土壤有机层碳、氮、磷,微生物生物量碳、氮含量及微生物呼吸均显著下降,其中微生物生物量碳依次为天然林(727.98 mg/kg)>次生林(554.56 mg/kg)>人工林(239.83 mg/kg),微生物生物量氮为天然林(72.56 mg/kg)>次生林(50.42 mg/kg)>人工林(20.78 mg/kg),而矿质层各测定变量在3个森林群落之间差异基本不显著.各森林群落有机层土壤碳、氮、磷,微生物生物量及呼吸均显著高于矿质层,而碳氮比和微生物生物量碳氮比在土壤层次之间差异不大.相关分析表明,土壤碳、氮、磷及化学计量比及微生物变量之间存在显著相关关系.综上所述,森林转换显著影响川西亚高山土壤碳、氮、磷化学计量及微生物生物量,且影响主要体现在土壤有机层.
The soil carbon, nitrogen and phosphorus stoichiometry, soil microbial biomass and respiration in the natural alpine coniferous forests, secondary birch forests, artificial spruce stands and mineral layers in the sub-alpine mountains of western Sichuan were compared and analyzed with the method of space replacement. The results showed that, Natural coniferous forest was transformed into secondary forest and plantation forest. The contents of soil organic carbon, nitrogen and phosphorus, microbial biomass carbon and nitrogen, and microbial respiration decreased significantly. The microbial biomass carbon followed by natural forest (727.98 mg / kg)> (554.56 mg / kg)> Artificial forest (239.83 mg / kg), Microbial biomass nitrogen (72.56 mg / kg), Secondary forest (50.42 mg / kg) The differences among the three forest communities were not significant.The soil organic carbon, nitrogen, phosphorus, microbial biomass and respiration in the forest community were significantly higher than those in the mineral layer, while the C / N and microbial biomass carbon and nitrogen There was no significant difference between the soil layers.Correlation analysis showed that there was a significant correlation between soil carbon, nitrogen, phosphorus and stoichiometry and microbial variables.In conclusion, forest conversion significantly affected the soil carbon and nitrogen ,phosphorus Stoichiometry and microbial biomass, and the impact is mainly reflected in the organic layer of soil.