Long-term time series of annual ecosystem production (1985–2010) derived from tree rings in Douglas-fir stands on Vancouver Island, Canada using a hybrid biometric-modelling approach

• Published in: Forest ecology and management Vol. 429; pp. 57 - 68
• Main Authors: Metsaranta, J.M., Trofymow, J.A., Black, T.A., Jassal, R.S.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-12-2018
• ISSN: 0378-1127; 1872-7042
• DOI: 10.1016/j.foreco.2018.06.040

•Tree-ring data and an ecosystem model were used to reconstruct past annual ecosystem production.•Net ecosystem production estimates corresponded with eddy covariance estimates from 1998 to 2010.•Coarse litterfall caused discrepancy in measured and modelled aboveground net primary production.•Hybrid biometric-modelling approach gives reliable data for estimating forest production.
We used a hybrid-biometric modelling approach that combines tree-ring based stand reconstruction and the Carbon Budget Model of the Canadian Forest Sector (CBM-CFS3) to estimate past magnitude and inter-annual variation of net primary production (NPP), net ecosystem production (NEP), and heterotrophic respiration (Rh) in plots located within the footprint of an eddy-covariance (EC) installation in a Douglas-fir stand of 1949 origin (DF49 or AmeriFlux CA-Ca1). Stand reconstruction estimated NEP showed excellent correspondence with EC-estimated NEP over the period 1998–2010 (r2 = 0.79, mean difference 24 gC m−2 year−1). Estimates of carbon use efficiency, aboveground NPP, and post-disturbance C dynamics following the harvest of DF49 in 2011 showed discrepancies between modelled estimates and independent data, which were attributed to underestimates of coarse litterfall in previous field studies and to uncertainty in the production, turnover, and post-mortality decay of non merchantable woody biomass in the CBM-CFS3. Despite these issues, the results provide further evidence of the potential use of tree-ring data to expand the availability of long-term estimates of annual ecosystem production and their ability to increase our understanding of forest C dynamics.