Fire is one of the major natural disturbances in the terrestrial ecosystem and profoundly impacts the structure and functions of forest ecosystems. With increases in temperature and extreme weather events, fire occurrence and burned area in boreal forests have increased markedly over past decades. Understanding how fire regimes will change in the future climate conditions have important implications for adaptation to climate change in forest management. The existing fire predictions are mainly based on climate-fire linkages accounted for climate-related changes such as temperature, precipitation, fuel moisture, and fire weather index, vegetation is assumed to remain relatively static in these studies. Recent studies have shown that changes in species composition have an indirect effect on fire regimes through altering fuel types and fuel distribution. Without accounting for the vegetation feedbacks, fire predicted based on climate-fire linkages may overestimate the frequency and size of fire disturbances because fuel type and structure moderate climate-fire linkages. 

A research team led by associate Prof. LIANG Yu from the Institute of Applied Ecology of the Chinese Academy of Sciences used a model coupling framework to integrate the dynamics of forest succession, climate-fire linkages, and vegetation feedback to fire regimes for projecting fire occurrence and burned area under the future climate conditions. 

In this study, the researchers found that climate change would increase fire occurrence density and burned area of boreal forests in the first 100 years. Whereas, the changes in forest composition would cause a reduction in fire occurrence density and burned area as deciduous species replace coniferous species in the next 150 years. Under climate change scenarios, the changes in fire regimes will accelerate the shifts of species composition in boreal forests. Vegetation feedback can override the direct effects of climate change on fire regimes when forest composition shifts significantly modify landscape flammability in the period 2100-2250. 

This study demonstrates that vegetation feedbacks could reduce the effects of climate change on fire regimes in boreal forests of northeastern China. Thus, the effects of vegetation feedbacks on fire regimes should be taken into consideration for promoting boreal forests adapt to climate change and reducing the frequency fire disturbance. Plant appropriately deciduous species such as aspen may be a good option for reducing fire occurrence probability and promoting boreal forest ecosystem adaption to climate change. 

The study was published in the Journal of Applied Ecology, entitled “The changes in species composition mediate direct effects of climate change on future fire regimes of boreal forests in northeastern China”. 

It was supported by the National Key R&D Program of China, the National Natural Science Foundation of China, and the National Biologic Carbon Sequestration Assessment Program under the U.S. Geological Survey Climate and Land Use Mission Area. 

Contact 

YUE Qian 

Institute of Applied Ecology, Chinese Academy of Sciences 

Tel: 86-24-83970324 

E-mail: yueqian@iae.ac.cn 

Web: http://english.iae.cas.cn