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

Microbial community functional diversity at 4℃、15℃ and 28℃ in the cultivated Black soil (0~20 cm) with different fertilizing treatmentsno 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.