贡嘎山树线过渡带土壤胞外酶活性及其化学计量比特征

[an error occurred while processing this directive]

李东¹^,², 田秋香², 赵小祥²^,³, 林巧玲²^,³, 岳朋芸²^,³, 姜庆虎², 刘峰²^,^*(

)

Soil extracellular enzyme activities and their stoichiometric ratio in the alpine treeline ecotones in Gongga Mountain, China

LI Dong¹^,², TIAN Qiu-Xiang², ZHAO Xiao-Xiang²^,³, LIN Qiao-Ling²^,³, YUE Peng-Yun²^,³, JIANG Qing-Hu², LIU Feng²^,^*(

)

图5. 贡嘎山树线过渡带土壤胞外酶活性(A)及其化学计量比(B)的非度量多维尺度(NMDS)分析。应力函数可以检验NMDS分析结果的优劣, 通常认为stress < 0.2时可用NMDS的二维点图表示, 其图形有一定的解释意义; 当stress < 0.1时, 可认为是一个好的排序。图中仅显示有显著影响的因素。BG, β-葡萄糖苷酶; CAT, 过氧化氢酶; CBH, 纤维素二糖水解酶; DN, 土壤可溶性氮含量; DOC, 土壤可溶性有机碳含量; LAP, 亮氨酸氨基肽酶; Leaf C:N, 优势树种叶片碳氮比; Lignin:N, 叶片木质素比氮; MBC, 微生物生物量碳含量; NAG, N-乙酰氨基葡萄糖苷酶; NO₃^--N, 硝态氮含量; POX, 多酚氧化酶; SOC, 土壤有机碳含量; TN, 全氮含量; XYL, 木聚糖水解酶。E_cn1、E_cn2表示微生物碳、氮酶活性计量比; CQI₁、CQI₂表示碳质量指数。

Fig. 5. Bray-Curtis-based non-metric multidimensional scaling (NMDS) of the soil enzyme activities (A) and enzyme stoichiometry (B) in the treeline ecotone in Gongga Mountain. The stress function can test the merit of NMDS analysis results. It is generally considered that stress < 0.2 can be represented by a two-dimensional point diagram of NMDS, and its graph has some interpretative significance; when stress < 0.1, it can be considered a good ranking. Only significant factors (p < 0.05) were showed in the figure. BG, β-1,4-glucosidase; CAT, catalase; CBH, cellobiohydrolase; DN, soil dissolved nitrogen content; DOC, soil dissolved organic carbon content; LAP, leucine aminopeptidase; Leaf C:N, carbon to nitrogen ratio of leaves of dominant species; Lignin:N, leaf lignin to nitrogen ratio; MBC, microbial biomass carbon content; NAG, β-N-acetyl glucosaminidase; NO₃^--N, nitrate nitrogen content; POX, phenol oxidase; SOC, soil organic carbon content; TN, total nitrogen content; XYL, xylosidase. E_cn1, E_cn2 indicate microbial carbon and nitrogen enzyme activity stoichiometry ratios; CQI₁, CQI₂ indicate carbon quality index.