The Fate of Organic Sources of Carbon in Moss‐rich Tundra Soil Microbial Communities: A Laboratory Experimental Study

• Published in: Journal of Eukaryotic Microbiology
• Main Author: Anderson, O. R.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2012
• Subjects: Tundra
• Online Access: http://dx.doi.org/10.1111/j.1550-7408.2012.00633.x; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1550-7408.2012.00633.x; https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1550-7408.2012.00633.x

Abstract Effects of glucose‐carbon supplementation on soil respiration and bacterial and protist biomass were investigated in laboratory studies of three soil samples from Alaskan tundra: spring tussock sample 1 (thin surface moss), spring tussock sample 2 (thick surface moss), and a summer tundra open field sample. Addition of 1% (w/v) glucose solution produced an immediate, pronounced two to three fold increase in respiration above basal rate, which declined over 4 h to baseline levels. Less than 1% (w/w) of glucose‐C supplement was respired during the respiratory spike, relative to the 89 μg/g added. A more substantial amount of the glucose‐C became incorporated in microbial biomass. The total difference in microbial carbon (μg/g) between the experimental treatments and controls without glucose after 1 wk was as follows: spring sample 1 (8), spring sample 2 (31), and summer sample (70). The percent (w/w) of glucose‐C incorporated was: spring sample 1 (5%), spring sample 2 (17%), and summer sample (39%), most attributed to biomass of bacteria and heterotrophic nanoflagellates. Although respiratory response to pulsed glucose‐C was minimal, the overall mean basal rate after 1 wk ranged between 4 and 6 nmol/min/g soil, indicating a significant assimilation and respiration of constituent soil organic carbon.