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A triple tree-ring constraint for tree growth and physiology in a global land surface model
- Source :
- Biogeosciences, Vol 18, Pp 3781-3803 (2021)
- Publication Year :
- 2021
- Publisher :
- Copernicus Publications, 2021.
-
Abstract
- Annually resolved tree-ring records extending back to pre-industrial conditions have the potential to constrain the responses of global land surface models at interannual to centennial timescales. Here, we demonstrate a framework to simultaneously constrain the representation of tree growth and physiology in the ORCHIDEE global land surface model using the simulated variability of tree-ring width and carbon (Δ13C) and oxygen (δ18O) stable isotopes in six sites in boreal and temperate Europe. We exploit the resulting tree-ring triplet to derive integrative constraints for leaf physiology and growth from well-known mechanistic relationships among the variables. ORCHIDEE simulates Δ13C (r=0.31–0.80) and δ18O (r=0.36–0.74) better than tree-ring width (r), with an overall skill similar to that of a tree-ring model (MAIDENiso) and another isotope-enabled global vegetation model (LPX-Bern). The comparison with tree-ring data showed that growth variability is not well represented in ORCHIDEE and that the parameterization of leaf-level physiological responses (stomatal control) to drought stress in the temperate region can be constrained using the interannual variability of tree-ring stable isotopes. The representation of carbon storage and remobilization dynamics emerged as a critical process to improve the realism of simulated growth variability, temporal carryover, and recovery of forest ecosystems after climate extremes. Simulated forest gross primary productivity (GPP) correlates with simulated tree-ring Δ13C and δ18O variability, but the origin of the correlations with tree-ring δ18O is not entirely physiological. The integration of tree-ring data and land surface models as demonstrated here should guide model improvements and contribute towards reducing current uncertainties in forest carbon and water cycling.
Details
- Language :
- English
- ISSN :
- 17264170 and 17264189
- Volume :
- 18
- Database :
- Directory of Open Access Journals
- Journal :
- Biogeosciences
- Publication Type :
- Academic Journal
- Accession number :
- edsdoj.5a8a6a5f4d448d6ba5fd3cdd650bbe1
- Document Type :
- article
- Full Text :
- https://doi.org/10.5194/bg-18-3781-2021