title: The active microbial diversity drives ecosystem multifunctionality and is physiologically related to carbon availability in Mediterranean semi-arid soils.
abstract: Biogeochemical processes and ecosystemic functions are mostly driven by soil microbial communities. However, most methods focus on evaluating the total microbial community and fail to discriminate its active fraction which is linked to soil functionality. Precisely, the activity of the microbial community is strongly limited by the availability of organic carbon (C) in soils under arid and semi-arid climate. Here, we provide a complementary genomic and metaproteomic approach to investigate the relationships between the diversity of the total community, the active diversity and ecosystem functionality across a dissolved organic carbon (DOC) gradient in southeast Spain. DOC correlated with the ecosystem multifunctionality index composed by soil respiration, enzyme activities (urease, alkaline phosphatase and β-glucosidase) and microbial biomass (phospholipid fatty acids, PLFA). This study highlights that the active diversity (determined by metaprotoemics) but not the diversity of the whole microbial community (evaluated by amplicon gene sequencing) is related to the availability of organic C and it is also connected to the ecosystem multifunctionality index. We reveal that DOC shapes the activities of bacterial and fungal populations in Mediterranean semi-arid soils and determines the compartmentalization of functional niches. For instance, Rhizobales thrived at high-DOC sites probably fuelled by metabolism of one-C compounds. Moreover, the analysis of proteins involved in the transport and metabolism of carbohydrates revealed that Ascomycota and Basidiomycota occupied different nutritional niches. The functional mechanisms for niche specialization were not constant across the DOC gradient.
authors.affiliation: Department of Soil and Water Conservation, CEBAS-CSIC, Campus Universitario de Espinardo, 30100, Murcia, Spain. fbastida@cebas.csic.es.
authors.forename: Felipe
authors.initials: F
authors.lastname: Bastida
authors.affiliation: Department of Soil and Water Conservation, CEBAS-CSIC, Campus Universitario de Espinardo, 30100, Murcia, Spain.
authors.forename: Irene F
authors.initials: IF
authors.lastname: Torres
authors.affiliation: Department of Soil and Water Conservation, CEBAS-CSIC, Campus Universitario de Espinardo, 30100, Murcia, Spain.
authors.forename: José L
authors.initials: JL
authors.lastname: Moreno
authors.affiliation: Laboratory of Environmental Microbiology, Institute of Microbiology of the CAS, Vídeňská 1083, Praha 4, 14220, Czech Republic.
authors.forename: Petr
authors.initials: P
authors.lastname: Baldrian
authors.affiliation: Department of Soil and Water Conservation, CEBAS-CSIC, Campus Universitario de Espinardo, 30100, Murcia, Spain.
authors.forename: Sara
authors.initials: S
authors.lastname: Ondoño
authors.affiliation: Department of Soil and Water Conservation, CEBAS-CSIC, Campus Universitario de Espinardo, 30100, Murcia, Spain.
authors.forename: Antonio
authors.initials: A
authors.lastname: Ruiz-Navarro
authors.affiliation: Department of Soil and Water Conservation, CEBAS-CSIC, Campus Universitario de Espinardo, 30100, Murcia, Spain.
authors.forename: Teresa
authors.initials: T
authors.lastname: Hernández
authors.affiliation: Department of Isotope Biogeochemistry, Helmholtz-Centre for Environmental Research - UFZ, Permoserstr. 15, 04318, Leipzig, Germany.
authors.forename: Hans H
authors.initials: HH
authors.lastname: Richnow
authors.affiliation: Department of Molecular Systems Biology, Helmholtz-Centre for Environmental Research - UFZ, Permoserstr. 15, 04318, Leipzig, Germany.
authors.forename: Robert
authors.initials: R
authors.lastname: Starke
authors.affiliation: Department of Soil and Water Conservation, CEBAS-CSIC, Campus Universitario de Espinardo, 30100, Murcia, Spain.
authors.forename: Carlos
authors.initials: C
authors.lastname: García
authors.affiliation: Department of Molecular Systems Biology, Helmholtz-Centre for Environmental Research - UFZ, Permoserstr. 15, 04318, Leipzig, Germany.
authors.forename: Nico
authors.initials: N
authors.lastname: Jehmlich
mesh_terms: D044822:Biodiversity; D002244:Carbon / Q000737:chemistry*; D053978:Pentacyclic Triterpenes; D012987:Soil / Q000737:chemistry*; D012988:Soil Microbiology; D013030:Spain
chemical_list: D053978:Pentacyclic Triterpenes; D012987:Soil; C000598366:protoescigenin; D002244:Carbon
keywords: bacteria; community ecology; ecosystem services; fungi; genomics/proteomics; organic carbon