Publication Date:
2018-01-25
Description:
Decomposition of soil organic matter (SOM) in permafrost terrain and the production of greenhouse gases is a key factor for understanding climate change-carbon feedbacks. Previous studies have shown that SOM decomposition is mostly controlled by soil temperature, soil moisture and carbon-nitrogen ratio (C:N). However, focus has generally been on site-specific processes and little is known about variations in the controls on SOM decomposition across Arctic sites. For assessing SOM decomposition, we retrieved 241 samples from 101 soil profiles across three contrasting Arctic regions, and incubated them in the laboratory under aerobic conditions. We assessed soil carbon losses (C loss ) five times during an one-year incubation. The incubated material consisted of near-surface active layer (AL NS ), subsurface active layer (AL SS ), peat and permafrost samples. Samples were analysed for carbon, nitrogen, water content, δ 13 C, δ 15 N and dry bulk density (DBD). While no significant differences were observed between total AL SS and permafrost C loss over one year incubation (2.3 ± 2.4 % and 2.5 ± 1.5 % C loss , respectively), AL NS samples showed higher C loss (7.9 ± 4.2 %). DBD was the best explanatory parameter for active layer C loss across sites. Additionally, results of permafrost samples show that C:N ratio can be used to characterise initial C loss between sites. This dataset on the influence of abiotic parameter on microbial SOM decomposition can improve model simulations of Arctic soil CO 2 production by providing representative mean values of CO 2 production rates as well as identifying standard parameters or proxies for upscaling potential CO 2 production from site to regional scales.
Print ISSN:
0148-0227
Topics:
Biology
,
Geosciences
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