TY - JOUR
T1 - Combining remote sensing data with process modelling to monitor boreal conifer forest carbon balances
AU - Smith, Benjamin
AU - Knorr, Wolfgang
AU - Widlowski, Jean-Luc
AU - Pinty, Bernard
AU - Gobron, Nadine
PY - 2008
Y1 - 2008
N2 - Approaches combining satellite-based remote sensing data with ecosystem modelling offer potential for the accurate assessment of changes in forest carbon balances, for example, in support of emission credits under the Kyoto Protocol. We investigate the feasibility of two alternative methods of using satellite derived data to constrain the behaviour of a dynamic ecosystem model, in order to improve the model’s predictions of the net primary production (NPP) of conifer forests in northern Europe (4–308E, 55–708N). The ecosystem model incorporates a detailed description of forest stand structure and biogeochemical processes. The satellite product comprises multi-spectral reflectance data from the VEGETATION sensor. The first method combines satellite-based estimates of FPAR, the fraction of incoming photosynthetically active radiation absorbed by vegetation, with the model’s predictions of the efficiency with which trees use the incoming radiation to fix carbon. Results obtained using this method averaged 0.22 kg C m_2 yr_1 for the NPP of conifer and mixed forests across the study area, and compared well with forest-inventory based estimates for Sweden. The second method uses forest stand descriptions derived by application of an inverse radiation transfer scheme to VEGETATION data to prescribe stand structure in the ecosystem model simulations. Predictions obtained by this method averaged 0.31 kg C m_2 yr_1, somewhat high compared to forest inventory data for central and northern Sweden. Simulations by the ecosystem model when driven only by climate, CO2 and soils data, but unconstrained by satellite information, yielded an average NPP of 0.41 kg C m_2 yr_1, which is likely to be an overestimate. Summed over the study area, the NPP estimates amounted to 0.16–0.23 Gt C yr_1, around 6–9% of the NPP of all boreal forest globally or 0.3–0.4% of terrestrial NPP globally. The investigated methods of combining process modelling and products derived from remote sensing data offer promise as a step towards the development of operational tools for monitoring forest carbon balances at large scales.
AB - Approaches combining satellite-based remote sensing data with ecosystem modelling offer potential for the accurate assessment of changes in forest carbon balances, for example, in support of emission credits under the Kyoto Protocol. We investigate the feasibility of two alternative methods of using satellite derived data to constrain the behaviour of a dynamic ecosystem model, in order to improve the model’s predictions of the net primary production (NPP) of conifer forests in northern Europe (4–308E, 55–708N). The ecosystem model incorporates a detailed description of forest stand structure and biogeochemical processes. The satellite product comprises multi-spectral reflectance data from the VEGETATION sensor. The first method combines satellite-based estimates of FPAR, the fraction of incoming photosynthetically active radiation absorbed by vegetation, with the model’s predictions of the efficiency with which trees use the incoming radiation to fix carbon. Results obtained using this method averaged 0.22 kg C m_2 yr_1 for the NPP of conifer and mixed forests across the study area, and compared well with forest-inventory based estimates for Sweden. The second method uses forest stand descriptions derived by application of an inverse radiation transfer scheme to VEGETATION data to prescribe stand structure in the ecosystem model simulations. Predictions obtained by this method averaged 0.31 kg C m_2 yr_1, somewhat high compared to forest inventory data for central and northern Sweden. Simulations by the ecosystem model when driven only by climate, CO2 and soils data, but unconstrained by satellite information, yielded an average NPP of 0.41 kg C m_2 yr_1, which is likely to be an overestimate. Summed over the study area, the NPP estimates amounted to 0.16–0.23 Gt C yr_1, around 6–9% of the NPP of all boreal forest globally or 0.3–0.4% of terrestrial NPP globally. The investigated methods of combining process modelling and products derived from remote sensing data offer promise as a step towards the development of operational tools for monitoring forest carbon balances at large scales.
KW - Kyoto Protocol
KW - carbon sequestration
KW - conifers
KW - forest ecology
KW - remote sensing
UR - http://handle.westernsydney.edu.au:8081/1959.7/uws:48687
U2 - 10.1016/j.foreco.2008.03.056
DO - 10.1016/j.foreco.2008.03.056
M3 - Article
SN - 0378-1127
VL - 255
SP - 3985
EP - 3994
JO - Forest Ecology and Management
JF - Forest Ecology and Management
IS - 12
ER -