Table 1.

Context data for sampling sites.

Site	Abbreviation	Location	Climatic zone	Biome	Dominant vegetation	Soil type	Carbon content (%)	pH	Moisture (% soil dry weight)	# of replicates	Sampling time	Reference	Sequencing method
Peatland soil ”Knudsenheia”	PsK	Ny-Ålesund, Norway (Svalbard)	Arctic	Fen wet land	Mosses	Organic	>80	7.3	1010	2	August 2009	Tveit et al., 2013	454 GS FLX Titanium
Peatland soil ”Solvatn”	PsS	Ny-Ålesund, Norway (Svalbard)	Arctic	Fen wet land	Mosses	Organic	>80	7.6	900	2	August 2009	Tveit et al., 2013	454 GS FLX Titanium
Mofette	MO	Hartoušov, Czech Republic	Temperate	Floodplain	Filipendula ulmaria	Organic	22	4.7	N.A.	3	July 2013	Beulig et al., 2016	Illumina HiSeq 2500
Mofette reference	MR	Hartoušov, Czech Republic	Temperate	Floodplain	Deschampsia cespitosa, Eriophorum vaginatum	Organic	23	5.3	N.A.	3	July 2013	Beulig et al., 2016	Illumina HiSeq 2500
Rothamsted grassland	RS	Rothamsted, United Kingdom	Temperate	Grassland	N.A.	Mineral	<3	4.9	33	2	July 2009	Geisen et al., 2015	454 GS FLX Titanium
Rotböhl	RB	Darmstadt, Germany	Temperate	Grassland	N.A.	Mineral	<2	7.1	32	1	January 2006	Urich et al., 2008	454 GS 20
Forest Litter	FL	Vienna woods, Austria	Temperate	Temperate deciduous forest	Fagus sylvatica	Organic	N.A.	N.A.	18	2	May 2008	Geisen et al., 2015	454 GS FLX
Forest Soil	FS	Vienna woods, Austria	Temperate	Temperate deciduous forest	Fagus sylvatica	Mineral	8	4.5–5.1	43–64	4	May 2008	Geisen et al., 2015	454 GS FLX
Mine L	MiL	Coto Txomin, Spain	Temperate	Shrubland	Ulex europaeus	Mineral	2.53	3.9	52	3	March 2011	Epelde et al., 2015	Illumina HiSeq 2000
Mine M	MiM	Coto Txomin, Spain	Temperate	Shrubland	Festuca rubra	Mineral	9	5.6	49	3	March 2011	Epelde et al., 2015	Illumina HiSeq 2000
Mine H	MiH	Coto Txomin, Spain	Temperate	Shrubland	Festuca rubra	Mineral	3.1	5.9	30	3	March 2011	Epelde et al., 2015	Illumina HiSeq 2000