Spatial variability of soil microbial biomass and its relationships with edaphic, vegetational and climatic factors in the Three-River Headwaters region on Qinghai-Tibetan Plateau

Abstract

a b s t r a c tThis study aims to investigate the level of soil microbial biomass (MB) and analyze the relationships between soil MB and edaphic, vegetational and climatic factors at high elevation sites (>3000 m). We collected soil samples from 0 to 10 cm soil depth in 259 plots at 55 sites across 6 biomes in Three-River Headwaters (TRH) region at 3280-5127 m elevation. Soil microbial biomass carbon and nitrogen (MBC and MBN) were measured with the chloroform fumigation-extraction method. Multivariate stepwise regression analyses were used to analyze the combined effects of edaphic, vegetational and climatic factors on soil MB. We found: (1) soil MBC and MBN had an average of 30.95 mmol C/kg dry soil and 5.84 mmol N/kg dry soil in TRH, respectively, and their values were found to be negatively correlated with elevation; (2) soil MB was found to be significantly different among different biomes, and this spatial variation could be explained by the levels of soil organic carbon and belowground plant biomass. Our results indicate that the MB at high elevation region might be very low, and the increasing trend of soil microbial biomass with elevation could reverse at higher elevations.

Contribution of deeper soil horizons to N and C cycling during the snow-free season in alpine tundra, NW Italy

“…Our mean Nmicr/TN in the topsoil (3.4%) was higher than that reported by Shen R. et al (2015) (2.5%), which instead was more similar to the mean value we found in the subsoil (2.9%). On the other hand, our mean Cmicr/TOC ratios in the topsoil (2.1%) and in the subsoil (2.5%) were both higher than those measured in the topsoil (1.1%) by Shen R. et al (2015) in the Tibetan Plateau (Table 4, part b).…”

“…Soil nitrogen (N) and carbon (C) cycling in alpine tundra ecosystem have been primarily investigated in the topsoil (0-10 cm), while the underlying subsoil has received much less attention (e.g. Fisk and Schmidt, 1996;Jaeger et al, 1999;Lipson et al, 1999;Shen C. et al, 2015;Shen R. et al, 2015). Even pedoclimatic factors, such as soil temperature and soil moisture, have been typically measured in the surface soil layer but not lower (e.g.…”

Improving soil quality for higher grain yields in Chinese wheat and maize production

“…The CF + PV treatment significantly increased the diversity of bacteria (Shannon index; Table ). Previous studies have indicated that the application of organic material increases soil bacterial diversity compared with controls (Shen, Xu, Li, Zhao, & Sheng, ; Mabuhay, Nakagoshi, & Isagi, ). The bacterial diversity of soil treated with manure was not significantly higher than the control in our experiment.…”

Peer Review #1 of "Effects of afforestation on water resource variations in the Inner Mongolian Plateau (v0.1)"

“…Following an assumption similar to that made by Budyko (1974), actual evapotranspiration can be estimated as follows (Shen et al 2015):…”