Silva Fennica (Jan 2001)
Tree stand development and carbon sequestration in drained peatland stands in Finland – a simulation study
Abstract
Drained peatland forests form an important timber resource in Finland. They also form a sink for atmospheric carbon (C) because of the increased growth and C sequestration rates following drainage. These rates have, however, been poorly quantified. We simulated the tree stand dynamics for drained peatland stands with and without cuttings over two stand rotations. Simulations were done on four peatland site types and two regions in Finland with different climatic conditions, using recently published peatland tree growth models applied in a stand simulator. We then calculated the amount of C stored in the stands on the basis of previously published tree-level biomass and C content models. Finally, we developed regression models to estimate C stores in the tree stands using stand stem volume as the predictor variable. In the managed stands, the mean growth (annual volume increment) ranged from 2 to 9 m3 haâ1 aâ1, depending on the rotation (first/second), site type and region. Total yield during one rotation varied from 250 to 920 m3 haâ1. The maximum stand volumes varied from 220 to 520 m3 haâ1 in the managed stands and from 360 to 770 m3 haâ1 in the unmanaged. By the end of the first post-drainage rotation the total C store in the managed stands had increased by 6â12 kg C mâ2 (i.e. 45â140 g C mâ2 aâ1) compared to that in the undrained situation. Averaged over two rotations, the increase in the total C store was 3â6 kg C mâ2. In the corresponding unmanaged stands the C stores increased by 8â15 kg mâ2 over the same periods. At stand level, the C stores were almost linearly related to the stem volume and the developed regression equations could explain the variation in the simulated C stores almost entirely.