Boreal Forest and Fire

sq. mi.sq. km. Boreal Forests Other Forests

Nearly continuous belt of coniferous trees across North America and Eurasia

Map source, Hare and Ritchie (1972).

Long, severe winters Short summers Low summer precipitation Climate associated with the Boreal Forest

Overlying formerly glaciated areas and areas of patchy permafrost Soils are podzols Soils are very acidic and often waterlogged Soils associated with the Boreal Forest

Vegetation is a mosaic of successional and subclimax plant communities Black and white spruce are characteristic species along with jack pine and balsam fir Successional species include alder (Alnus), birch (Betula), and aspen (Populus).

Black Spruce (Picea mariana)

Jack Pine (Pinus banksiana)

Lots of water bodies Muskegs

Patterns of annual area burned in the North American boreal forest illustrating a continuous rise in fire activity since the early 1970s (Kasischke 1999)

Boreal Fire Locations between

Fire Effects on Wildlife Populations

CARBON CYCLE

Fire influences carbon cycling both directly and indirectly in the boreal forest Direct: consumption of trees, understory vegetation, lichen, moss, litter, organic soil RESULT: instant flux of carbon to the atmosphere Indirect: 1) change in albedo (surface reflectivity Indirect: 2) vegetation succession RESULT: slow flux of carbon to the atmosphere RESULT: CO2 sequestration during regrowth

Fifty years of soil temperature data at a boreal forest site near Fairbanks, Alaska indicate oC warming, now approaching thaw. This warming will likely effect fire regimes and the occurrence of permafrost, which in turn will effect carbon storage. Data of Vladimir Romanovsky, 1999.