Wildfires in northern Siberian larch dominated communities

Abstract

The fire history of the northern larch forests within the permafrost zone in a portion of northern Siberia (∼66°N, 100°E) was studied. Since there is little to no human activity in this area, fires within the study area were mostly caused by lightning. Fire return intervals (FRI) were estimated on the basis of burn marks on tree stems and dates of tree natality. FRI values varied from 130 to 350yr with a 200 50yr mean. For southerly larch dominated communities, FRI was found to be shorter (77 20yr at ∼ 61°N, and 82 7at 64°N), and it was longer at the northern boundary (∼71°) of larch stands (320 50yr). During the Little Ice Age period in the 16th-18th centuries, FRI was approximately twice as long those as recorded in this study. Fire caused changes in the soil including increases in soil drainage and permafrost thawing depth, and a radial growth increase to about twice the background value (with more than six times observed in extreme cases). This effect may simulate the predicted warming impact on the larch growth in the permafrost zone. © 2011 IOP Publishing Ltd.