Changes in species composition mediate direct effects of climate change on future fire regimes of boreal forests in northeastern China

1.    Direct effects of climate change (i.e.,
temperature rise, changes in seasonal precipitation, wind patterns, and
atmospheric stability) affect fire regimes of boreal forests by altering
fire behavior, fire seasons, and fuel moisture. Climate change also alters
species composition and fuel characteristics, which subsequently alter
fire regimes. However, indirect effects of climate change are often
simplified or neglected in the direct climate-fire relationship models and
dynamic global vegetation models. This may result in high uncertainties
associated with existing projections of fire regimes for climate change
scenarios. Moreover, few studies have examined fire regime predictions
beyond the 21st century, and consequently, how the fire regimes of boreal
forests would respond to climate change at the long-term (>100
years) is not clear. 2.    We develop a coupled modeling
framework integrating direct and indirect effects of climate change to
predict fire occurrence probability and burned area for boreal forests in
northeastern China. We applied repeated-measures ANOVA to quantify direct
and indirect effects of climate change on fire regimes in the short (0-50
years), medium (60-100 years), and long-term (150-200 years). 3. 
  Results showed that for the 21st century, direct effects of
climate change are likely to exert a stronger influence on fire regimes
than indirect effects. However, increases in fire occurrence probability
and burned area will accelerate the transition of boreal forests to
temperate forests in the period 2100-2200, and thereby reduce fire
occurrence probability and burned area. This suggests that vegetation
change will mediate direct effects of climate change on fire regimes of
boreal forests in the long-term. 4.   
Synthesis and applications. Vegetation change will mediate direct effects
of climate change on fire regimes of boreal forests in the long-term. This
finding suggested that policy makers may consider adaptive management by
planting deciduous species to reduce fire occurrence probability and
resistant management by reducing competition to promote boreal species
under changing climate conditions.