1. Pools and fluxes of carbon in three Norway spruce ecosystems along a climatic gradient in Sweden.
- Author
-
Kleja, Dan, Svensson, Magnus, Majdi, Hooshang, Jansson, Per-Erik, Langvall, Ola, Bergkvist, Bo, Johansson, Maj-Britt, Weslien, Per, Truusb, Laimi, Lindroth, Anders, and Ågren, Göran
- Subjects
- *
CARBON , *SOILS , *ORGANIC compounds , *VEGETATION surveys , *BIOTIC communities , *PLANT litter , *HUMUS - Abstract
This paper presents an integrated analysis of organic carbon (C) pools in soils and vegetation, within-ecosystem fluxes and net ecosystem exchange (NEE) in three 40-year old Norway spruce stands along a north-south climatic gradient in Sweden, measured 2001–2004. A process-orientated ecosystem model (CoupModel), previously parameterised on a regional dataset, was used for the analysis. Pools of soil organic carbon (SOC) and tree growth rates were highest at the southernmost site (1.6 and 2.0-fold, respectively). Tree litter production (litterfall and root litter) was also highest in the south, with about half coming from fine roots (<1 mm) at all sites. However, when the litter input from the forest floor vegetation was included, the difference in total litter input rate between the sites almost disappeared (190–233 g C m−2 year−1). We propose that a higher N deposition and N availability in the south result in a slower turnover of soil organic matter than in the north. This effect seems to overshadow the effect of temperature. At the southern site, 19% of the total litter input to the O horizon was leached to the mineral soil as dissolved organic carbon, while at the two northern sites the corresponding figure was approx. 9%. The CoupModel accurately described general C cycling behaviour in these ecosystems, reproducing the differences between north and south. The simulated changes in SOC pools during the measurement period were small, ranging from −8 g C m−2 year−1 in the north to +9 g C m−2 year−1 in the south. In contrast, NEE and tree growth measurements at the northernmost site suggest that the soil lost about 90 g C m−2 year−1. [ABSTRACT FROM AUTHOR]
- Published
- 2008
- Full Text
- View/download PDF