Methanotrophs are core members of the diazotroph community in decaying Norway spruce logs
Mäkipää, R., Leppänen, S. M., Munoz, S. S., Smolander, A., Tiirola, M., Tuomivirta, T., & Fritze, H. (2018). Methanotrophs are core members of the diazotroph community in decaying Norway spruce logs. Soil Biology and Biochemistry, 120, 230-232. doi:10.1016/j.soilbio.2018.02.012
Published inSoil Biology and Biochemistry
DisciplineYmpäristötiede ja -teknologia
© the Authors. 2018 Published by Elsevier Ltd. This is an open access article distributed under the terms of the Creative Commons License.
Dead wood is initially a nitrogen (N) poor substrate, where the N content increases with decay, partly due to biological N2 fixation, but the drivers of the N accumulation are poorly known. We quantified the rate of N2 fixation in decaying Norway spruce logs of different decay stages and studied the potential regulators of the N2-fixation activity. The average rate for acetylene reduction in the decaying wood was 7.5 nmol ethylene g−1d−1, which corresponds to 52.9 μg N kg−1d−1. The number of nifH copies (g−1 dry matter) was higher at the later decay stages, but no correlation between the copy number and the in vitro N2 fixation rate was found. All recovered nifH sequences were assigned to the order Rhizobiales, and therein mostly (60%) to methane oxidizing genera. We confirm that nitrogen fixing methanotrophs are present in all the wood decay phases and suggest that their interaction between methane producing organisms in decaying wood should be further studied.