Biolog-Eco解析垦殖与自然恢复黑土微生物群落代谢功能季节变化

Seasonal Variations of Microbial Community Functional Diversity in Cultivated and Natural Restored Mollisols Using Biolog-Eco Method

为动态比较土壤垦殖前后微生物群落代谢功能是否发生变化,利用Biolog-Eco技术对不同季节自然恢复(NR)和垦殖不同施肥处理[不施肥(NoF)、施化肥(CF)和化肥配施有机肥(CFM)]黑土微生物在4℃、15℃和28℃培养温度下的代谢功能多样性进行了研究。结果表明:4种处理在同一采样时期不同培养温度下,Biolog微孔板的单孔平均颜色变化率(Average Well Color Development,AWCD)值均表现为28℃>15℃>4℃,即微生物代谢活性随培养温度的升高而升高;同一采样时期样品在相同培养温度下黑土微生物对碳源的代谢能力总体呈现为NR>CFM>CF>NoF。微生物在积雪融化期和积雪覆盖期对碳源的利用能力高于植物生长季节。主成分分析(Principle Component Analysis,PCA)结果显示,不同采样时期NoF样品和其它3种处理相比微生物功能多样性差异较大;NR、CF和CFM在作物非生长季节(3月、4月和12月)的样品在PCA图中分散度小于在作物生长季节(6月)的样品。该研究结果综合表明,垦殖处理较自然恢复降低了土壤微生物群落对碳源的代谢能力,但并未改变微生物群落功能;不同季节土壤微生物功能多样性存在差异,NR、CF和CFM细菌群落在作物生长的夏季对碳源的利用能力差异最大。

Microbial community functional diversity at 4 ℃ 、15 ℃ and 28 ℃ in the cultivated Black soil( 0 ~ 20 cm) with different fertilizing treatments [no fertilizer( NoF),chemical fertilizer( CF) and chemical fertilizer plus manure( CFM) ]and in a neighboring plot of natural restoration( NR) in Northeast China was investigated using Biolog-Eco method in this study. The results showed that the average well color development( AWCD) of the four treatments from a same sampling time under different incubation temperatures was in the order of 28 ℃ > 15 ℃ > 4 ℃ and the metabolic activity of samples collected on the same sampling time and incubation temperature was in the order of NR > CFM > CF > NoF. The utilization of carbon sources used by samples collected on thawing period and snow cover period was higher than those collected on the period of active plant growth. Principle component analysis( PCA) with Biolog data indicated that the differences of the metabolic function of NoF were more obvious than other three treatments among four sampling times,and the samples from CF、CFM and NR collected on the periods of no plant growth gathered closer than those from the period of active plant growth. In sum,Black soil cultivated decreased the utilization of carbon source,but did not change the function of microbial diversity,which varied with seasons. Much differences of metabolic ability were observed among CF、CFM and NR which were collected on summer season.