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【目的】评价帽儿山地区纯林与混交林(红皮云杉纯林、长白落叶松纯林、胡桃楸和红皮云杉混交林、胡桃楸和长白落叶松混交林、水曲柳和红皮云杉混交林、水曲柳和长白落叶松混交林)土壤生态系统中参与土壤碳代谢的微生物群落特征。【方法】借助Biolog~(MT)技术,比较了纯林与混交林之间根际土壤微生物对不同碳源类型的利用情况。【结果】不同林型土壤微生物平均颜色变化率(AWCD)呈现阔叶林高于针叶林,胡桃楸针-阔混交林型中针叶林土壤微生物AWCD值优于与水曲柳混交林型。胡桃楸针-阔混交林中,针叶林的Shannon指数显著地高于水曲柳针-阔混交林。Simpson优势度指数与Shannon多样性指数变化趋势较为相似。羧酸、氨基酸和糖类这3类碳源是导致微生物代谢呈现差异的主要碳源。长白落叶松、红皮云杉与水曲柳混交后对糖类、羧酸和氨基酸3种主要碳源的利用程度均有所下降,可能是导致AWCD值较低的原因之一。【结论】胡桃楸针-阔混交林比水曲柳针-阔混交林以及针叶纯林更有利于土壤微生物群落的碳代谢功能发挥。
【Objective】 The objective of this study was to evaluate the effects of pure forest and mixed forest (pure stands of Picea koraiensis, pure forest of Larch, Juglans mandshurica and Picea koraiensis mixed forest, Juglans mandshurica and Larix olgensis mixed forest, Mixed forest of Picea koraiensis and mixed forests of Ash and Larix olgensis) microbial community involved in soil carbon metabolism in soil ecosystem. 【Method】 Biolog MT method was used to compare the utilization of rhizospheric microorganisms in pure carbon and mixed forests with different carbon source types. 【Result】 The results showed that the average color change rate (AWCD) of soil microorganisms in different forest types was higher than that in coniferous forest. The AWCD values of soil microbe in middle-coniferous forest of Juglans mandshurica were better than those in mixed forest . In the Juglans sigia-Coniferous-broad-leaved mixed forest, the Shannon’s index of the coniferous forest was significantly higher than that of the needlewood-broadleaf mixed forest. Simpson dominance index and Shannon diversity index trends are similar. Carboxylic acids, amino acids and carbohydrates are the three major sources of carbon that lead to differences in microbial metabolism. The utilization of three major carbon sources of sugars, carboxylic acids and amino acids after the mixture of P. elongata, P. koraiensis and P. pseudoacacia decreased, which may be one of the reasons for the low AWCD value. 【Conclusion】 Juglans mandshurica - broadleaved mixed forest is more conducive to the carbon metabolism of soil microbial communities than that of the mixed stands of Pinus densiflora - broadleaved mixed forest and coniferous forest.