The restoration age of Robinia pseudoacacia plantation impacts soil microbial biomass and microbial community structure in the Loess Plateau

Microbial community assembly is influenced by a continuum (actually the trade-off) between deterministic and stochastic processes. An understanding of this ecological continuum is of great significance for drawing inferences about the effects of community assembly processes on microbial community structure and function. Here, we investigated the driving forces of soil microbial community assembly in three different environmental contexts located on subalpine coniferous forests of the Loess Plateau in Shanxi, China. The variation in null deviations and phylogenetic analysis showed that a continuum existed between deterministic and stochastic processes in shaping the microbial community structure, but deterministic processes prevailed. By integrating the results of redundancy analysis (RDA), multiple regression tree (MRT) analysis and correlation analysis, we found that soil organic carbon (SOC) was the main driver of the community structure and diversity patterns. In addition, we also found that SOC had a great influence on the community assembly processes. In conclusion, our results show that deterministic processes always dominated assembly processes in shaping bacterial community structure along the three habitat contexts.

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Response of soil microbial biomass, activities, and community structure at a pine stand in northeastern Germany 5 years after thinning

Canadian Journal of Forest Research ◽

10.1139/x06-039 ◽

2006 ◽

Vol 36 (6) ◽

pp. 1427-1434 ◽

Cited By ~ 17

Author(s):

Sebastian Maassen ◽

Hannu Fritze ◽

Stephan Wirth

Keyword(s):

Community Structure ◽

Microbial Community ◽

Microbial Biomass ◽

Microbial Community Structure ◽

Basal Respiration ◽

Organic Layer ◽

Soil Microbial Community Structure ◽

Soil Microbial ◽

Significant Difference ◽

Northeastern Germany

A thinned and an unthinned treatment were compared in a 62-year-old pine stand located in northeastern Germany (Brandenburg, Ost-Prignitz, Revier Beerenbusch) (year of thinning: 1999, degree of canopy opening: 0.4). Samples of the organic layer (O) and the mineral horizon (Aeh) of an acid brown earth were collected along a transect at each treatment in November 2003 and April 2004. Substrate induced respiration, basal respiration, and a suite of enzymes involved in the degradation of lignocellulose (endocellulase, exocellulase, β-glucosidase, endoxylanase, exoxylanase, phenoloxidase, peroxidase) were assayed. Microbial community structure and relative biomass of bacteria, actinomycetes, and fungi were assayed by phospholipid fatty acid analysis. Five years after thinning, microbial biomass, basal respiration, and enzyme activities in both soil layers did not differ significantly between thinned and unthinned treatments. However, the analysis of soil microbial community structure revealed a significant difference between the thinned and unthinned treatment at both sampling dates. Thus, it was concluded that thinning had not yet resulted in any response in soil microbial activities at the site under study, but since early evidence of change in the microbial community was detected, long-term monitoring and additional studies on mineralization activities are required.

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