title: Effect of altitude and season on microbial activity, abundance and community structure in Alpine forest soils.
abstract: In the current context of climate change, the study of microbial communities along altitudinal gradients is especially useful. Only few studies considered altitude and season at the same time. We characterized four forest sites located in the Italian Alps, along an altitude gradient (545-2000 m a.s.l.), to evaluate the effect of altitude in spring and autumn on soil microbial properties. Each site in each season was characterized with regard to soil temperature, physicochemical properties, microbial activities (respiration, enzymes), community level physiological profiles (CLPP), microbial abundance and community structure (PLFA). Increased levels of soil organic matter (SOM) and nutrients were found at higher altitudes and in autumn, resulting in a significant increase of (soil dry-mass related) microbial activities and abundance at higher altitudes. Significant site- and season-specific effects were found for enzyme production. The significant interaction of the factors site and incubation temperature for soil microbial activities indicated differences in microbial communities and their responses to temperature among sites. CLPP revealed site-specific effects. Microbial community structure was influenced by altitudinal, seasonal and/or site-specific effects. Correlations demonstrated that altitude, and not season, was the main factor determining the changes in abiotic and biotic characteristics at the sites investigated.
authors.affiliation: Institute of Microbiology, University of Innsbruck, Technikerstrasse 25, A-6020 Innsbruck, Austria.
authors.forename: José A
authors.initials: JA
authors.lastname: Siles
authors.affiliation: Institute of Microbiology, Academy of Sciences of the Czech Republic, v.v.i., Vídeňská 1083, CZ-142 20 Prague 4, Czech Republic Institute for Environmental Studies, Faculty of Science, Charles University in Prague, Benatska 2, CZ-128 01 Prague 2, Czech Republic.
authors.forename: Tomas
authors.initials: T
authors.lastname: Cajthaml
authors.affiliation: Division Forestry, Autonomous Province of Bozen/Bolzano, Brennerstrasse 6, I-39100 Bozen/Bolzano, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Minerbi
authors.affiliation: Institute of Microbiology, University of Innsbruck, Technikerstrasse 25, A-6020 Innsbruck, Austria Rosa.Margesin@uibk.ac.at.
authors.forename: Rosa
authors.initials: R
authors.lastname: Margesin
mesh_terms: D000531:Altitude; D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D044822:Biodiversity; D057231:Climate Change; D065928:Forests; D007558:Italy; D010802:Phylogeny; D012621:Seasons; D012987:Soil / Q000737:chemistry; D012988:Soil Microbiology; D013696:Temperature
chemical_list: D012987:Soil
keywords: Alpine soils; PLFA; altitude; enzymes; forest; respiration