TY - JOUR
T1 - The importance of age-related decline in forest NPP for modeling regional carbon balances
AU - Zaehle, Sönke
AU - Sitch, Stephen
AU - Prentice, I. Colin
AU - Liski, Jari
AU - Cramer, Wolfgang
AU - Erhard, Markus
AU - Hickler, Thomas
AU - Smith, Benjamin
PY - 2006
Y1 - 2006
N2 - We show the implications of the commonly observed age-related decline in aboveground productivity of forests, and hence forest age structure, on the carbon dynamics of European forests in response to historical changes in environmental conditions. Size-dependent carbon allocation in trees to counteract increasing hydraulic resistance with tree height has been hypothesized to be responsible for this decline. Incorporated into a global terrestrial biosphere model (the Lund-Potsdam-Jena model, LPJ), this hypothesis improves the simulated increase in biomass with stand age. Application of the advanced model, including a generic representation of forest management in even-aged stands, for 77 European provinces shows that model-based estimates of biomass development with age compare favorably with inventory-based estimates for different tree species. Model estimates of biomass densities on province and country levels, and trends in growth increment along an annual mean temperature gradient are in broad agreement with inventory data. However, the level of agreement between modeled and inventory-based estimates varies markedly between countries and provinces. The model is able to reproduce the present-day age structure of forests and the ratio of biomass removals to increment on a European scale based on observed changes in climate, atmospheric CO2 concentration, forest area, and wood demand between 1948 and 2000. Vegetation in European forests is modeled to sequester carbon at a rate of 100 Tg C/yr, which corresponds well to forest inventory-based estimates.
AB - We show the implications of the commonly observed age-related decline in aboveground productivity of forests, and hence forest age structure, on the carbon dynamics of European forests in response to historical changes in environmental conditions. Size-dependent carbon allocation in trees to counteract increasing hydraulic resistance with tree height has been hypothesized to be responsible for this decline. Incorporated into a global terrestrial biosphere model (the Lund-Potsdam-Jena model, LPJ), this hypothesis improves the simulated increase in biomass with stand age. Application of the advanced model, including a generic representation of forest management in even-aged stands, for 77 European provinces shows that model-based estimates of biomass development with age compare favorably with inventory-based estimates for different tree species. Model estimates of biomass densities on province and country levels, and trends in growth increment along an annual mean temperature gradient are in broad agreement with inventory data. However, the level of agreement between modeled and inventory-based estimates varies markedly between countries and provinces. The model is able to reproduce the present-day age structure of forests and the ratio of biomass removals to increment on a European scale based on observed changes in climate, atmospheric CO2 concentration, forest area, and wood demand between 1948 and 2000. Vegetation in European forests is modeled to sequester carbon at a rate of 100 Tg C/yr, which corresponds well to forest inventory-based estimates.
KW - Age-related decline
KW - Forest management
KW - Lund-Potsdam-Jena model (LPJ)
KW - Magnani hypothesis
KW - Plant hydraulic architecture
KW - Terrestrial biosphere modeling
UR - http://www.scopus.com/inward/record.url?scp=33747123330&partnerID=8YFLogxK
U2 - 10.1890/1051-0761(2006)016[1555:TIOADI]2.0.CO;2
DO - 10.1890/1051-0761(2006)016[1555:TIOADI]2.0.CO;2
M3 - Article
C2 - 16937818
AN - SCOPUS:33747123330
SN - 1051-0761
VL - 16
SP - 1555
EP - 1574
JO - Ecological Applications
JF - Ecological Applications
IS - 4
ER -