Climate-sensitive integrated stand growth model (CS-ISGM) of Changbai larch (Larix olgensis) plantations

Forest growth modeling faces a new challenge of supporting forest management in the context of climate change. A traditional growth and yield model has the potential to be modified to function as a climate-sensitive model and thus could be applied to adaptive forest management. We developed a climate-sensitive integrated stand growth model (CS-ISGM) for larch plantations in Jinlin Province, northeast China. The parameters were estimated using systems of equations with errors-in-variables. Cross-validation using national forest inventory plot data showed that this model had better performance than the conventional ISGM model. The mean temperature of the driest quarter and precipitation of the wettest month were the most important climate predictors for the stand basal area and dominant height growth. The growth, productivity and mortality of the larch plantations were simulated using CS-ISGM with future climate scenarios (RCP2.5, RCP4.6, and RCP8.0) from 2040 to 2080. The results showed that future climate changes could facilitate stand growth and accelerate mortality. Compared with the current climate, the periodical annual increment (PAI) values were 12.23%, 10.43%, and 0.11% higher; the stand productivity (SP) values were 5.48%, 4.22% and 1.50% higher; and the mortality trees were 16.62%, 13.00% and 4.17% higher under the RCP2.6, RCP4.5 and RCP8.5 scenarios, respectively. Middle-aged and near-mature forests would have higher growth than young and mature forests, but near-mature, mature and over-mature forests would have higher mortality than young and middle-aged forests. This model could be used to project larch stand growth under future climate change conditions and adaptation measures according to the simulation results from different climate scenarios.