Measurements and simulations using the 3-PG model of the water balance and water use efficiency of a lodgepole pine stand following mountain pine beetle attack

•The 3-PG model was modified to include effects of mountain pine beetle attack.•Eddy-covariance measurements in an attacked stand were used to validate the model.•Agreement between measured and modelled stand water and carbon fluxes was good.•Understory growth contributed significantly to stand recovery following attack.