301. Soil attributes and microclimate are important drivers of initial deadwood decay in sub-alpine Norway spruce forests
- Author
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Roberto Tognetti, Marco Marchetti, Giulia Fravolini, Markus Egli, Fabio Lombardi, Judith Ascher-Jenull, Curdin Derungs, Paolo Cherubini, María Gómez-Brandón, Tommaso Bardelli, University of Zurich, and Egli, Markus
- Subjects
0106 biological sciences ,Environmental Engineering ,010504 meteorology & atmospheric sciences ,Soil texture ,Weathering ,Soil science ,DEADWOOD DECAY ,010603 evolutionary biology ,01 natural sciences ,Carbon cycle ,2305 Environmental Engineering ,Environmental Chemistry ,910 Geography & travel ,Waste Management and Disposal ,Water content ,0105 earth and related environmental sciences ,biology ,Moisture ,Picea abies ,Edaphic ,biology.organism_classification ,Pollution ,2311 Waste Management and Disposal ,10122 Institute of Geography ,2304 Environmental Chemistry ,2310 Pollution ,Soil water ,Environmental science - 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.
- Published
- 2016