Biotic and abiotic responses of the boreal forests carbon cycles to climate change and management

Abstract

Boreal forests are a large carbon sink and are as important as the tropical forests due to huge carbon stock in both plants and soils. However, the boreal forests carbon sink is affected by climate change on one hand and by management on the hand in last several decades and the need for better understanding of how boreal forests respond to climate and management in a long term is still urgent. In this study we used the process-based CoupModel combining the long-term in-situ measurements to successfully constrain the energy, water and carbon fluxes modeling in a boreal coniferous forest. We noticed that during the extreme drought years, there were large impacts from temperature on boreal forests growth, but not from water and radiation. The harvest of plants has made the boreal forests exposed to lower thresholds of environmental factors, but the impacts of harvest on net carbon fluxes was found just for short period due to the higher ecosystem respiration after harvest. The calibrated model generally depicted good performance for water, energy and carbon fluxes at hourly, monthly, yearly and multi-year scales, but the systematic biases indicated that considering the elevated atmospheric CO2 and nutrients dynamics, the climate variations as well as the more detailed management impacts on boreal ecosystems is of importance. Our study provided new insights into the boreal forests responses to climate change and management over a long period and contributed to better understanding of boreal forests for both the modeling and observation communities.