Relationships between GPP, NPP, NEP, Ra, Rh and Re in forest ecosystems Sebastiaan Luyssaert with...
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Transcript of Relationships between GPP, NPP, NEP, Ra, Rh and Re in forest ecosystems Sebastiaan Luyssaert with...
Relationships between GPP, NPP, NEP, Ra, Rh and Re in forest ecosystems
Sebastiaan Luyssaert
with contributions of 40+ research groups
Sebastiaan Luyssaert and contributions of 40+ research groups
Relationships between GPP, NPP, NEP, Ra, Rh and Re in forest ecosystems
• Forest play an important role in the global C-cycle
• Since 1970 ongoing effort to estimate production and respiration
• Considerable uncertainties remain
• Assembled a comprehensive global database
Introduction
Objectives
• Explain some important feature of the database
• Identify data gaps
• Present relationships GPP, NPP, NEP, Ra, Rh and Re
• Present CO2-budgets per biome
Relationships between GPP, NPP, NEP, Ra, Rh and Re in forest ecosystems
Sebastiaan Luyssaert and contributions of 40+ research groups
The database
Relationships between GPP, NPP, NEP, Ra, Rh and Re in forest ecosystems
• Consistent NPP data
• Consistent uncertainty
• Ancillary information
Sebastiaan Luyssaert and contributions of 40+ research groups
The database
Relationships between GPP, NPP, NEP, Ra, Rh and Re in forest ecosystems
Expert judgement accounting for :
- Applied methodology
- Number of observations
• Consistent NPP data
• Consistent uncertainty
• Ancillary information
Sebastiaan Luyssaert and contributions of 40+ research groups
The database
Relationships between GPP, NPP, NEP, Ra, Rh and Re in forest ecosystems
• Consistent NPP data
• Consistent uncertainty
• Ancillary information
- Coordinates, elevation, climatic region,
growth form, management, tree species- Observed MAT, APS, LAI, age, height,
BA, diameter, density, biomass- Monthly temperature, precipitation,
rainy days, cloud cover data CRU- Modelled radiation components, air
humidity, N-deposition, soil composition- NDVI
Sebastiaan Luyssaert and contributions of 40+ research groups
Data
Relationships between GPP, NPP, NEP, Ra, Rh and Re in forest ecosystems
• 2000+ flux observations
• 380 sites
• 130 GPP, Re & NEP
• 250 NPP
• 130 Rh & Rs
• 35 Ra
Sebastiaan Luyssaert and contributions of 40+ research groups
Data gaps
Relationships between GPP, NPP, NEP, Ra, Rh and Re in forest ecosystems
• For GPP, NPP, NEP & Re
need:
- Boreal ecosystems
- Tropical ecosystems
Sebastiaan Luyssaert and contributions of 40+ research groups
Data gaps
Relationships between GPP, NPP, NEP, Ra, Rh and Re in forest ecosystems
• For Ra & Rh need:
- All biomes except temperate
humid
Sebastiaan Luyssaert and contributions of 40+ research groups
Dependence of GPP
Relationships between GPP, NPP, NEP, Ra, Rh and Re in forest ecosystems
Sebastiaan Luyssaert and contributions of 40+ research groups
• High GPP: warm wet
• Low GPP: cold dry
Relationships between GPP, NPP, NEP, Ra, Rh and Re in forest ecosystems
Dependence of GPP
Sebastiaan Luyssaert and contributions of 40+ research groups
Relationships between GPP, NPP, NEP, Ra, Rh and Re in forest ecosystems
?
Dependence of GPP
Sebastiaan Luyssaert and contributions of 40+ research groups
Relationships between GPP, NPP, NEP, Ra, Rh and Re in forest ecosystems
?
Dependence of GPP
Sebastiaan Luyssaert and contributions of 40+ research groups
Relationships between GPP, NPP, NEP, Ra, Rh and Re in forest ecosystems
?
Dependence of GPP
Sebastiaan Luyssaert and contributions of 40+ research groups
Relationships between GPP, NPP, NEP, Ra, Rh and Re in forest ecosystems
Dependence of GPP, NPP, Re and Rh
• GPP ~ MAT, LAI, P
• NPP ~ MAT, LAI, Rg
• Re ~ MAT, LAI, P
• Rh ~ MAT, ?
Sebastiaan Luyssaert and contributions of 40+ research groups
Relationships between GPP, NPP, NEP, Ra, Rh and Re in forest ecosystems
Dependence of NEP
• NEP ~ GPP
Sebastiaan Luyssaert and contributions of 40+ research groups
Relationships between GPP, NPP, NEP, Ra, Rh and Re in forest ecosystems
Dependence of NEP
• NEP ~ GPP
Sebastiaan Luyssaert and contributions of 40+ research groups
Relationships between GPP, NPP, NEP, Ra, Rh and Re in forest ecosystems
Dependence of NEP
NEP ?
• Age
• Management
Sebastiaan Luyssaert and contributions of 40+ research groups
source
sink
Relationships between GPP, NPP, NEP, Ra, Rh and Re in forest ecosystems
Dependence of NPP/GPP
Ra, insuf. data
• NPP/GPP
Sebastiaan Luyssaert and contributions of 40+ research groups
Relationships between GPP, NPP, NEP, Ra, Rh and Re in forest ecosystems
Dependence of NPP/GPP
• NPP/GPP data
• NPP/GPP max
production
Sebastiaan Luyssaert and contributions of 40+ research groups
Relationships between GPP, NPP, NEP, Ra, Rh and Re in forest ecosystems
Dependence of NPP/GPP
NPP/GPP unmanaged
sites
Sebastiaan Luyssaert and contributions of 40+ research groups
Relationships between GPP, NPP, NEP, Ra, Rh and Re in forest ecosystems
Dependence of NPP/GPP
Management > Temp
Sebastiaan Luyssaert and contributions of 40+ research groups
Relationships between GPP, NPP, NEP, Ra, Rh and Re in forest ecosystems
Components of the CO2-balance
• Benchmark for model validation
• Closure problem
Sebastiaan Luyssaert and contributions of 40+ research groups
Closure of the CO2-balance
Relationships between GPP, NPP, NEP, Ra, Rh and Re in forest ecosystems
Sebastiaan Luyssaert and contributions of 40+ research groups
Relationships between GPP, NPP, NEP, Ra, Rh and Re in forest ecosystems
Global CO2-balance
• Uncertainty when models
follow the observations
Sebastiaan Luyssaert and contributions of 40+ research groups
Relationships between GPP, NPP, NEP, Ra, Rh and Re in forest ecosystems
Conclusions
• Database of field-observations available for model validation
• Missing 2 out of 8 climate regions
• Climate dependence of GPP, NPP, Re but not of NEP
• NPP/GPP ratio is not 0.475
• Substantial closure terms indicate shortcomings of field-observations
Sebastiaan Luyssaert and contributions of 40+ research groups
Relationships between GPP, NPP, NEP, Ra, Rh and Re in forest ecosystems
We want more...
• Presentation Denis Lousteau: Management effects on the annual
carbon balance of forests
• Poster Ilaria Inglima: NPP drives Rh in forest ecosystems
• Task force presentations Martin Jung: Comparison of models and
observations
Sebastiaan Luyssaert and contributions of 40+ research groups
Relationships between GPP, NPP, NEP, Ra, Rh and Re in forest ecosystems
ContributorsI. Inglima, M. Jung, M. Reichstein, D. Papale, S. Piao, E.-D. Schulze, L. Wingate, G. Matteucci, M. Aubinet, C. Beer, C. Bernhofer, K.G. Black, D. Bonal, J.Chambers, P. Ciais, K.J. Davis, E.H. Delucia, A.J. Dolman, A. Don, B. Gielen, J. Grace, A. Granier, A. Grelle, T. Griffis, T. Grünwald, G. Guidolotti, P.J. Hanson, R. Harding, D. Hollinger, P. Kolari, B. Kruijt, W. Kutsch, F. Lagergren, T. Laurila, B. Law, G. Le Maire, A. Lindroth, F. Magnani, M. Marek, J. Mateus, M. Migliavacca, L. Misson, L. Montagnani, J. Moncrieff, E. Moors, J.W. Munger, E. Nikinmaa, D. Loustau, G. Pita, C. Rebmann, A.D. Richardson, O. Roupsard, N. Saigusa, M.J. Sanz, G. Seufert, L. Soerensen, J. Tang, R. Valentini, T. Vesala and I. Janssens
Funding
Belgian Research Foundation (FWO), CarboEurope-IP and Antwerp University
Sebastiaan Luyssaert and contributions of 40+ research groups