高黎贡山旱冬瓜林下土壤微生物碳源代谢多样性分析

Diversity Analysis of Carbon Source Metabolism of Alnus nepalensis Soil Microbes in Mt. Gaoligong

用Biolog生态平板分析法，对高黎贡山国家自然保护区海拔900-1800m梯度的旱冬瓜林下土壤微生物群落碳源代谢多样性进行分析，比较不同海拔的旱冬瓜林下土壤微生物群落碳源代谢的差异。结果表明，土壤微生物群落碳源代谢功能的变化随着海拔的变化而发生变化，土壤微生物群落碳源代谢利用的丰富度指数（S）、物种丰富度指数（H）均随海拔的增加而增大。旱冬瓜林下的土壤微生物群落碳源代谢活性，随着海拔上升逐渐增加；所采集的6个梯度旱冬瓜林下土壤微生物对6类碳源的利用存在差异，对于羧酸类和碳水化合物类利用程度较高，对其他种类化合物利用程度较低；Biolog-Eco微平板反应72h后土壤微生物碳源代谢的平均颜色变化率（AWCD）值，利用主成分分析的方法分析土壤微生物碳源代谢，代谢基质主成分1的贡献率为60．3％，起分异作用的主要是碳水化合物，有10种，氨基酸化合物与羧酸化合物各占5种；主成分2的贡献率21．3％，起分异作用的主要是芳香化合物。高黎贡山国家自然保护区旱冬瓜林下，土壤微生物群落碳源代谢多样性的分布是随着海拔的升高而增大，不符合“中部膨胀”这一高山植物多样性研究的普遍结果。

The diversity of carbon source metabolism of soil microbial community of Alnus nepalensis in 900 -1 800 m of Mt. Gaoligong was analyzed based on Biolog Eco plate method, and the differences of metabolism at differ- ence elevations were compared. The results showed that the metabolic function of soil microbe changes with the change of altitude, the Substrate richness （S） and Shannon index （H） of soil microbial community using carbon source increases with the increaseing elevation, and so the metabolic activity does. The utilization of soil microbes to 6 types of carbon sources at six elevations were different. In general, the carboxylic acids and carbohydrates were used more while less use of other compounds. The average well color development （AWCD） of 72 h soil mi- crobial by using PCA （principal component analysis） method showed that the contribution of PC1 of the soil mi-crobes metabolism substrates in six elevation gradient spots was 60. 3 %, the determinant carbon sources for the differences were carbohydrates and had 10 kinds. The contribution of PC2 was 21.3 %, the determinant carbon sources for the differences were aromatic compounds. The distribution of metabolic diversity of soil microbial com- munities of Alnus nepalensis in Mt. Gaoligong increased with the increasing elevation and this result do not comply with the common result of plant diversity ＂central bulge＂ findings.