Impacts of climate change on biological rotation of Larix olgensis plantations for timber production and carbon storage in northeast China using the 3-PGmix model

Biological rotation length is a key parameter of even-aged forest management. Future climate change is expected to affect forest growth and thus modify biological rotation age, but knowledge about the effect of climate change on the rotation for both timber production and carbon storage remains limited from process-based growth model. The biological rotation age (BRA) of Larix olgensis plantations in China is technically set for 40 years according to the principle of maximizing timber production, and it is necessary to further examine the BRA with consideration of site quality differences and climate change. On the basis of 164 sample plots from the National Forest Inventory across the Jilin Province, Northeast China, we use the process-based model 3-PG(mix) to simulate the change of the BRA of Larix olgensis plantations for timber production and carbon storage under climate change. Different climate scenarios are investigated across different site productivity levels. Under the current climate scenario, the BRAs for timber production and carbon storage are approximately 23.8-41.5 years and 25.0-46.4 years, respectively. The BRAs are reduced by 2-9 years under RCP 4.5 and RCP 8.5 climate scenarios. The BRA modification by climate change was site-dependent, and stands with good productivity sites led to shorter BRAs than those with poor productivity sites. The 3-PG(mix) model effectively simulates the dynamic change of stand volume and biomass for larch plantations. Future climate change with rising temperature, increased precipitation and elevated CO2 concertration is conducive to the growth of stand volume and carbon storage in the order of RCP 8.5 > RCP 4.5 > current. Results can provide scientific implications for adaptive management of Larix olgensis plantations, and shorter biological rotation is suggested for rotation modification under the future climate change in the region.