Influence of logging on the effects of wildfire in Siberia

The Russian boreal zone supports a huge terrestrial carbon pool. Moreover, it is a tremendous reservoir of wood products concentrated mainly in Siberia. The main natural disturbance in these forests is wildfire, which modifies the carbon budget and has potentially important climate feedbacks. In addition, both legal and illegal logging increase landscape complexity and affect burning conditions and fuel consumption. We investigated 100 individual sites with different histories of logging and fire on a total of 23 study areas in three different regions of Siberia to evaluate the impacts of fire and logging on fuel loads, carbon emissions, and tree regeneration in pine and larch forests. We found large variations of fire and logging effects among regions depending on growing conditions and type of logging activity. Logged areas in the Angara region had the highest surface and ground fuel loads (up to 135 t ha−1), mainly due to logging debris. This resulted in high carbon emissions where fires occurred on logged sites (up to 41 tC ha−1). The Shushenskoe/Minusinsk and Zabaikal regions are characterized by better slash removal and a smaller amount of carbon emitted to the atmosphere during fires. Illegal logging, which is widespread in the Zabaikal region, resulted in an increase in fire hazard and higher carbon emissions than legal logging. The highest fuel loads (on average 108 t ha−1) and carbon emissions (18–28 tC ha−1) in the Zabaikal region are on repeatedly burned unlogged sites where trees fell on the ground following the first fire event. Partial logging in the Shushenskoe/Minusinsk region has insufficient impact on stand density, tree mortality, and other forest conditions to substantially increase fire hazard or affect carbon stocks. Repeated fires on logged sites resulted in insufficient tree regeneration and transformation of forest to grasslands. We conclude that negative impacts of fire and logging on air quality, the carbon cycle, and ecosystem sustainability could be decreased by better slash removal in the Angara region, removal of trees killed by fire in the Zabaikal region, and tree planting after fires in drier conditions where natural regeneration is hampered by soil overheating and grass proliferation.

[1]  A. Soja,et al.  Fire emissions estimates in Siberia: evaluation of uncertainties in area burned, land cover, and fuel consumption , 2013 .

[2]  A. Soja,et al.  Fire Emissions Estimates in Siberia: Evaluation of Uncertainties in Area Burned, Land Cover, and Fuel Consumption , 2012 .

[3]  D. Mcrae,et al.  Fire impact on carbon storage in light conifer forests of the Lower Angara region, Siberia , 2011 .

[4]  A. Sukhinin,et al.  Effects of fires in ribbon-like pine forests of southern Siberia , 2011, Contemporary Problems of Ecology.

[5]  A. Vivchar,et al.  Wildfires in Russia in 2000–2008: estimates of burnt areas using the satellite MODIS MCD45 data , 2011 .

[6]  Corey J A Bradshaw,et al.  Urgent preservation of boreal carbon stocks and biodiversity. , 2009, Trends in ecology & evolution.

[7]  M. Turetsky,et al.  Impacts of climate change on fire activity and fire management in the circumboreal forest , 2009 .

[8]  Stephen V. Stehman,et al.  Combining MODIS and Landsat imagery to estimate and map boreal forest cover loss , 2008 .

[9]  E. Ponomarev Wystepowanie pozarow lasu w Syberii Srodkowej w zaleznosci od szerokosci geograficznej i ocena uszkodzenia lasow , 2008 .

[10]  F. Achard,et al.  The effect of climate anomalies and human ignition factor on wildfires in Russian boreal forests , 2008, Philosophical Transactions of the Royal Society B: Biological Sciences.

[11]  F. Achard,et al.  Areas of rapid forest-cover change in boreal Eurasia , 2006 .

[12]  Yu. N. Samsonov,et al.  Variability of Fire Behavior, Fire Effects, and Emissions in Scotch Pine Forests of Central Siberia , 2006 .

[13]  A. Lankin Forest product exports from the Russian Far east and eastern Siberia to China: status and trends: China and forest trade in the Asia-pacific region: implications for forests and livelihoods , 2005 .

[14]  W. R. Cofer,et al.  Estimating fire emissions and disparities in boreal Siberia (1998–2002) , 2004 .

[15]  P. Vandergert,et al.  Illegal logging in the Russian Far East and Siberia , 2003 .

[16]  R. Birdsey,et al.  Carbon storage in forests and peatlands of Russia , 1998 .

[17]  James S. Clark,et al.  Fire in boreal ecosystems of Eurasia: First results of the Bor Forest island fire experiment, Fire Research Campaign Asia-North (FIRESCAN) , 1994 .

[18]  Van Wagner The Line Intersect Method in Forest Fuel Sampling , 1968 .