African Journal of Biotechnology Vol. 11(37), pp. 9064-9073, 8 May, 2012 Available online at http://www.academicjournals.org/AJB DOI: 10.5897/AJB12.284 ISSN 1684–5315 © 2012 Academic Journals Full Length Research Paper Dynamic of soil microbial-community: Terminal restriction fragment length polymorphism analysis on natural secondary succession of Pinus tabulaeformis Carr. in the forest region of Loess Plateau, China Jin-cheng WANG 1,2 , Ming-bo JING 1,2 , Zhong-min DONG 3 , Tian-lin ZHOU* 1 and Jian LIANG* 2 1 University Provincial Key Laboratory For Protection and Utilization of Longdong Bio-resources in Gansu province, college of life science and technology, Longdong University, Qiangyang, Gansu 745000, P R China. 2 School of Life Science, Shaanxi Normal University, P R China. 3 Department of Biology, Saint Mary's University, Halifax B3H, Canada. Accepted 16 April, 2012 In order to assess the dynamics of microbial-diversity through vegetation successions, sample sites for soil investigation at the 10a, 25a, 40a, 75a natural secondary Pinus tabulaeformis Carr. forests were established in the forest region of Loess Plateau, China. With the succession extension, soil microbial biomass carbon (MBC), moisture content, soil organic carbon (SOC) as well as total N also exhibited an increase before decreasing trend with succession gradient. Soil indexes of the soil shannon diversity index (H), which incorporates both richness and evenness of all soil microbial-species observed in the plots according to T-RFs peaks composition determined by terminal restriction fragment length polymorphism (T-RFLP), also exhibited a similar trend with soil physicochemical properties during the succession. In the late-succession of 75a, its soil fertility and microbial-community structure is distant from other three stages, suggesting that it may be a specific stage to the recession succession. The result of a dendrogram of hierarchical cluster of the microbial-community structure of four succession stages showed that 75a was distant to the other three sample sites, and 25a and 40a represented the most similar microbial-community structure of all stages. It was concluded that the underground succession of natural secondary P. tabulaeformis Carr. forests in the forest region of Loess Plateau, China, is significantly linked to its aboveground. We infer that natural secondary succession of P. tabulaeformis Carr forest will be replaced by the Qercu sliaotungensis in the coming centuries in the forest region of Loess Plateau, China. Key words: Soil microbial-community; natural secondary succession, T-RFLP, Loess Plateau. INTRODUCTION Succession generally refers to the biological changes that occur in an ecosystem after the clearing or exposure of an area, often resulting in predictable sequences of species composition shifts. Plants and sessile animals have long been the focus of succession studies, primarily due to the perceived physical and ecological dominance of the irrespective landscapes (Redford and Fierer, 2009; *Corresponding author. E-mail: wensent20002002@163.com; tonghail@126.com. Wehenkel et al., 2011). Despite their ubiquity, abundance, and diversity, surprisingly few studies have examined succession patterns in microbial communities. This is partly due to methodological reasons, as it is difficult to describe the full extent of microbial diversity in a given sample using traditional, culture-based methods (Li et al., 2004). Current methods for assessing soil quality give only an incomplete picture of the status of the soil system. Several indicators for assessing soil quality, namely organic matter, topsoil depth, infiltration, aggregation, pH,