黄顶菊（Flaveriabidentis）入侵对土壤微生物功能多样性的影响

外来植物入侵对土壤生物多样性的影响已成为生态学领域的研究热点之一。运用Biolog技术和氯仿熏蒸浸提法研究了黄顶菊入侵对土壤微生物群落功能多样性及土壤微生物量的影响。结果表明，黄顶菊入侵后土壤微生物代谢活性显著升高；土壤微生物群落平均吸光值（4WCD）的变化趋势为：入侵地根际土（RPs）〉入侵地根围土（Bs）〉未入侵地（CK），且差异显著；而CK的功能多样性指数（日）高于BS，RPS亦高于Bs，差异均显著（P〈O．05）。主成分分析结果表明，黄顶菊入侵使土壤微生物群落的碳源利用方式和代谢功能发生改变。对不同碳源利用的分析结果表明，糖类、氨基酸类、羧酸类和聚合物为土壤微生物利用的主要碳源。入侵样地Bs和RPS的微生物量碳分别比CK高27．05％、121．52％；BS和RPS的微生物量氮分别比CK高37．40％、79．80％。相关性分析表明，AWCD与微生物量碳和微生物量氮均呈极显著正相关（P〈0．01）。由此可知，黄顶菊入侵增强了入侵地土壤微生物代谢活性，降低了土壤微生物群落的功能多样性，增加了土壤微生物量碳、氮水平。

Effects of Flaveria bidentis Invasion on Soil Microbial Functional Diversity

The influence of invasive plant invasion on soil biodiversity has become one of popular issues of ecology. In present study, the ef- fect of Flaveria bidentis, an invasive plant, on functional diversity of soil microbial communities and soil microbial biomass was investigated by using Biolog-ECO technique and chloroform fumigation extraction. Soil samples were collected in invaded area bulk soil（ BS ）, rhizosphere soil（ RPS ） and non-invasion area （CK） in August, 2012. The results showed that the soil microbial metabolic activity significantly increased following the invasion of F.bidentis. The average well color development（A WCD ） which directly reflected the microbial activities changed as following： RPS〉BS〉CK, with significant difference （P〈0.05）. The CK was significantly higher in Shannon-Wiener index （H） of soil microbial community than BS with significant rhizosphere effect detected. The principal component analysis（PCA） indicated that the variance contri- bution rate of PC1 and PC2 were 45.68% and 19.83%, respectively. Carbon source utilization ways of soil microbial community changed following the invasion of F. bidentis. The main carbon source of soil microorganisms were sugars, amino acids, carboxylic acid and polymer. Soil microbial biomass carbon of BS and RPS were increased by 27.05%, 121.52% compared with CK, soil microbial biomass nitrogen of BS and RPS were also increased by 37.40%, 79.80%. Correlation analysis showed that the A WCD had highly significantly （P〈0.O1） positive correlation with soil microbial biomass carbon and nitrogen. Therefore, the function of soil microbial metabolism and soil microbial biomass carbon and nitrogen were enhanced, while the soil microbial community functional diversity was reduced following the invasion of F. bidentis.