Abstract
Wood harvesting in boreal forests typically consists of
sequential harvesting operations within a rotation: a few
thinnings and a final felling. The aim of this paper is
to model differentiated relative global warming potential
(GWP) coefficients for stemwood use from different
thinnings and final fellings, and correction factors for
long-lived wood products, potentially applicable in life
cycle assessment studies. All thinnings and final
fellings influence the development of forest carbon
stocks. The climate impact of a single harvesting
operation is generated in comparison with no harvesting,
thus encountering a methodological problem on how to
handle the subsequent operations. The dynamic forest
stand simulator MOTTI was applied in the modelling of
evolution of forest carbon stocks at landscape level in
Southern Finland. The landscape-level approach for
climate impact assessment gave results similar to some
stand-level approaches presented in previous literature
that included the same forest C pools and also studied
the impacts relative to the no-harvest situation. The
climate impacts of stemwood use decreased over time. For
energy use, the impacts were higher or similar in the
short term and 0-50% lower in the midterm in comparison
with an identical amount of fossil CO2. The impacts were
to some extent (approximately 20-40%) lower for wood from
intermediate thinnings than for wood from final fellings
or first thinnings. However, the study reveals that
product lifetime has higher relative influence on the
climate impacts of wood-based value chains than whether
the stemwood originates from thinnings or final fellings.
Although the evolution of future C stocks in unmanaged
boreal forests is uncertain, a sensitivity analysis
suggests that landscape-level model results for climate
impacts would not be sensitive to the assumptions made on
the future evolution of C stocks in unmanaged forest.
Energy use of boreal stemwood seems to be far from
climate neutral.
Original language | English |
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Pages (from-to) | 334-345 |
Journal | Global Change Biology: Bioenergy |
Volume | 8 |
Issue number | 2 |
DOIs | |
Publication status | Published - 2016 |
MoE publication type | A1 Journal article-refereed |
Keywords
- boreal forest
- climate impacts
- forest bioenergy
- forest growth model
- global warming potential
- landscape
- long-lived wood products
- stemwood
- thinning wood