Regional carbon fluxes from an observationally constrained dynamic ecosystem model: Impacts of disturbance, CO₂ fertilization, and heterogeneous land cover

Model results were evaluated against a regional network of eddy covariance flux towers and analyzed about the roles of disturbance, forest management, and CO₂ fertilization. The model captured modern regional vegetation structure with worst comparison in wetlands.

Model net ecosystem exchange of CO₂ (NEE) was highly correlated on monthly (r² = 0.65) and annual (r² = 0.53) timescales to 7 years of NEE observed at a 396-m-tall eddy covariance (EC) tower and to 2 years of growing season NEE from 13 regional stand-scale EC sites of varying cover and age (r² = 0.64). Model summer NEE had higher than observed net uptake for the tall tower and mature hardwood sites, and correlation to growing season ecosystem respiration at these sites was poor (r² = 0.09).