title: Soil attributes and microclimate are important drivers of initial deadwood decay in sub-alpine Norway spruce forests.
abstract: Deadwood is known to significantly contribute to global terrestrial carbon stocks and carbon cycling, but its decay dynamics are still not thoroughly understood. Although the chemistry of deadwood has been studied as a function of decay stage in temperate to subalpine environments, it has generally not been related to time. We therefore studied the decay (mass of deadwood, cellulose and lignin) of equal-sized blocks of Picea abies wood in soil-mesocosms over two years in the Italian Alps. The 8 sites selected were along an altitudinal sequence, reflecting different climate zones. In addition, the effect of exposure (north- and south-facing slopes) was taken into account. The decay dynamics of the mass of deadwood, cellulose and lignin were related to soil parameters (pH, soil texture, moisture, temperature) and climatic data. The decay rate constants of Picea abies deadwood were low (on average between 0.039 and 0.040y(-1)) and of lignin close to zero (or not detectable), while cellulose reacted much faster with average decay rate constants between 0.110 and 0.117y(-1). Our field experiments showed that local scale factors, such as soil parameters and topographic properties, influenced the decay process: higher soil moisture and clay content along with a lower pH seemed to accelerate wood decay. Interestingly, air temperature negatively correlated with decay rates or positively with the amount of wood components on south-facing sites. It exerted its influence rather on moisture availability, i.e. the lower the temperature the higher the moisture availability. Topographic features were also relevant with generally slower decay processes on south-facing sites than on north-facing sites owing to the drier conditions, the higher pH and the lower weathering state of the soils (less clay minerals). This study highlights the importance of a multifactorial consideration of edaphic parameters to unravel the complex dynamics of initial wood decay.
authors.affiliation: Department of Bioscience and Territory, University of Molise, Contrada Fonte Lappone snc, 86090 Pesche (IS), Italy. Electronic address: giulia.fravolini@email.unimol.it.
authors.forename: Giulia
authors.initials: G
authors.lastname: Fravolini
authors.affiliation: Department of Geography, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland. Electronic address: markus.egli@geo.uzh.ch.
authors.forename: Markus
authors.initials: M
authors.lastname: Egli
authors.affiliation: Department of Geography, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland.
authors.forename: Curdin
authors.initials: C
authors.lastname: Derungs
authors.affiliation: WSL Swiss Federal Institute for Forest, Snow and Landscape Research, Zürcherstrasse 111, 8903 Birmensdorf, ZH, Switzerland. Electronic address: paolo.cherubini@wsl.ch.
authors.forename: Paolo
authors.initials: P
authors.lastname: Cherubini
authors.affiliation: Institute of Microbiology, University of Innsbruck, Technikerstr. 25d, 6020 Innsbruck, Austria; Department of Agrifood and Environmental Science, University of Florence, Piazzale delle Cascine 28, I-50144 Florence, Italy. Electronic address: judith.ascher@unifi.it.
authors.forename: Judith
authors.initials: J
authors.lastname: Ascher-Jenull
authors.affiliation: Institute of Microbiology, University of Innsbruck, Technikerstr. 25d, 6020 Innsbruck, Austria. Electronic address: Maria.Gomez-Brandon@uibk.ac.at.
authors.forename: María
authors.initials: M
authors.lastname: Gómez-Brandón
authors.affiliation: Institute of Microbiology, University of Innsbruck, Technikerstr. 25d, 6020 Innsbruck, Austria; Department of Agrifood and Environmental Science, University of Florence, Piazzale delle Cascine 28, I-50144 Florence, Italy. Electronic address: tommaso.bardelli@unifi.it.
authors.forename: Tommaso
authors.initials: T
authors.lastname: Bardelli
authors.affiliation: Department of Bioscience and Territory, University of Molise, Contrada Fonte Lappone snc, 86090 Pesche (IS), Italy; The EFI Project Centre on Mountain Forests (MOUNTFOR), Edmund Mach Foundation, San Michele all'Adige, Italy. Electronic address: tognetti@unimol.it.
authors.forename: Roberto
authors.initials: R
authors.lastname: Tognetti
authors.affiliation: Department of AGRARIA, Mediterranean University of Reggio Calabria, Località Feo di Vito, 89122 Reggio Calabria (RC), Italy. Electronic address: fabio.lombardi@unirc.it.
authors.forename: Fabio
authors.initials: F
authors.lastname: Lombardi
authors.affiliation: Department of Bioscience and Territory, University of Molise, Contrada Fonte Lappone snc, 86090 Pesche (IS), Italy. Electronic address: marchettimarco@unimol.it.
authors.forename: Marco
authors.initials: M
authors.lastname: Marchetti
keywords: Alps; Cellulose; Deadwood decay; Exposure; Lignin; Soil