ABSTRACT
This chapter describes a process-based ecosystem model (FinnFor) for studying the impacts of climate change on the dynamics of a managed boreal forest ecosystem. The basic assumption was that climate change affects canopy photosynthesis and the consequent tree growth, including the growth of foliage, branches, stems, coarse roots and fi ne roots. Climate change implies an increase in atmospheric CO2 concentration and temperature, with impacts on cloudiness, precipitation and air humidity and radiation falling on tree crowns (Fig. 13.1). Changes in atmospheric factors also affect soil moisture and temperature, which control decay of soil organic matter (litter, humus) and cycle of nitrogen (Strandman et al. 1993, Väisänen et al. 1994, Kellomäki and Väisänen 1997, Ge et al. 2010):
( ) ( ) ( ) ( ) ( ) ( ) ( , , ) ( )T nc n gcs a up aG f P f R f L f f W f N f T C P f M (13.1)
where GT is the total growth (foliage, branches, stems, coarse roots fi ne roots), Pnc is canopy photosynthesis, Rn is net radiation interception, L is leaf area, gcs is canopy conductance, Wa is available soil water, Nup is uptake of nitrogen, T is air temperature, Ca isatmospheric CO2,P is precipitation and M is management.
