Table 3.

Bacterial and fungal families identified altogether by clustering analyses (fclust) as key actors in basal soil respiration (soil), straw mineralization (straw), and the priming effect.

Mineralisation	Incubation Time	Model	Bacteria	Unknown	B.Planctomycetaceae	B.Acidobacteria-Gp1	B.Acidobacteria-Gp2	B.Thermomonosporaceae	B.Ktedonobacteraceae	B.Undefined	B.Bradyrhizobiaceae	B.Acidobacteria-Gp4	B.Hyphomicrobiaceae	B.Acetobacteraceae	B.Chitinophagaceae	B.Conexibacteraceae	B.Cystobacteraceae	B.Mycobacteriaceae	B.Pseudonocardiaceae	B.Burkholderiaceae	B.Oxalobacteraceae	B.Polyangiaceae	B.Gemmatimonadaceae	B.Chloroplast	B.Acidobacteria-Gp6	B.Chthonomonadaceae	B.Acidobacteria-Gp7	B.Streptomycetaceae	B.Rhodospirillaceae	B.Micromonosporaceae	B.Fervidicoccaceae	B.Acidimicrobineae-incertae-sedis	B.Paenibacillaceae	B.Xanthomonadaceae	B.Beijerinckiaceae	B.Bacillaceae	B.Comamonadaceae	B.Catenulisporaceae	B.Nocardioidaceae	B.Caulobacteraceae	B.Actinospicaceae	B.Acidobacteria-Gp13	B.Bdellovibrionaceae	B.Solirubrobacteraceae	B.Acidobacteria-Gp5	B.Rubrobacteraceae	B.Haliangiaceae	B.Planococcaceae	B.Sinobacteraceae	B.Coxiellaceae	B.Cyanobacteria.Chloroplast-F1	B.Methylocystaceae	B.Geodermatophilaceae	B.Rhizobiales-incertae-sedis	B.Armatimonadaceae	B.Acidobacteria-Gp3	B.Xanthobacteraceae	B.Flavobacteriaceae	B.Pasteuriaceae	B.Phyllobacteriaceae	B.Methylobacteriaceae	B.Nitrospiraceae	B.Microbacteriaceae
soil	7 d	fclust									***														∙		∙				***							***	.											∙	∙	***
											A+														E		D				B+							B+	C+											D	E	A+
	42 d	fclust									***							∙		∙		***											∙					***							***	***
											A+							D		D		B+											E					C−							A+	B+
straw	7 d	fclust											***	***														∙						∙	∙				***																	***	***				∙
													B−	B−														D						E	C				A+																	B−	A+				C
	42 d	fclust		***				***					***							***		∙		***			***		∙						***	∙		***			***					∙							***
				A+				A+					A+							D−		E		D−			C+		F						B+	E		C+			A+					E							D−
priming effect	7 d	fclust					***																												∙	***				***				***	***			***				***				***	***			***
							D−																												E	A+				A+				D−	B+			C−				A+				C−	C−			B+
	42 d	fclust		***																***		***							***												***								***											***
				A+																C−		A+							C−												A+								C−											C−
			Fungi	F.Unclassified	F.Unknown	F.Tricholomataceae	F.Environmental	F.Glomeraceae	F.Herpotrichiellaceae	F.Mortierellaceae	F.Tubeufiaceae	F.Phaeosphaeriaceae	F.Myxotrichaceae	F.Trichocomaceae	F.Chaetomiaceae	F.Coniophoraceae	F.Teratosphaeriaceae	F.Davidiellaceae	F.Nectriaceae	F.Strophariaceae	F.Endogonaceae	F.Lyophyllaceae	F.Hypocreaceae	F.Pleurotaceae	F.Bulgariaceae	F.Mycosphaerellaceae	F.Entolomataceae	F.Pyronemataceae	F.Pluteaceae	F.Boletaceae	F.Helotiaceae	F.Tremellaceae	F.Coniochaetaceae	F.Cordycipitaceae	F.Hyaloscyphaceae	F.Clavicipitaceae	F.Pleosporaceae	F.Lycoperdaceae	F.Gomphaceae	F.Marasmiaceae	F.Corticiaceae	F.Monoblepharidaceae	F.Stereaceae	F.Plectosphaerellaceae	F.Magnaporthaceae	F.Ajellomycetaceae	F.Didymellaceae	F.Agaricaceae	F.Massariaceae	F.Agyriaceae	F.Orbiliaceae	F.Pezizaceae	F.Ophiocordycipitaceae	F.Montagnulaceae	F.Rhizophydiaceae	F.Trechisporaceae	F.Ophiostomataceae	F.Kickxellaceae	F.Bionectriaceae	F.Sarcosomataceae	F.Ambisporaceae	F.Ustilaginaceae	F.Auriculariaceae
soil	7 d	fclust					***																	.																													.		.
							B+																	D																													D		C
	42 d	fclust							.		***			***		***							.																																		***
									E		C−			B+		C−							E																																		C−
straw	7 d	fclust		.							***																.															***					***
				E							B−																D															A+					B−
	42 d	fclust									.																													***						***							***									***	***
											F																													B+						C+							A+									B+	B+
priming effect	7 d	fclust									***						***											***	***					***													.													***	***
											C−						A+											A+	C−					D−													E													A+	B+
	42 d	fclust										***			***		.																													***						.		***
												A+			B+		E																													A+						E		A+

A midpoint (·) indicates that the family was identified as key by the variable selection procedure and (***) indicates that the significance was at p < 0.001. Cells are colored depending on if the family is identified as (green or pink) key by the clustering model or as (blue) negligible. Cells colored in pink were also previously identified as key by the multi-linear model performed on separated bacterial and fungal communities’ analyses (see Table 2). The sign indicates the direction, positive (+) or negative (−), of the family’s contribution to SOM decomposition activity. The letter (A to F) indicates the most significant functional group to which a class of relative abundance of the family was assigned. Families were ranked from left to right in descending order of relative abundance.