New Paper: The climate, the fuel and the land use: long-term regional variability of biomass burning in boreal forests

I am very happy to share this new paper about fire regime variability between Scandinavia and North America by Chiara Molinari and colleagues:

Molinari C., Lehsten V., Blarquez O., Carcaillet C., Davis B. A. S., Kaplan J. O., Clear J., Bradshaw R. H. W. 2018. The climate, the fuel and the land use: long-term regional variability of biomass burning in boreal forests. Global Change Biology, 1–18. https://doi.org/10.1111/gcb.14380 

Abstract

The influence of different drivers on changes in North American and European bor- eal forests biomass burning (BB) during the Holocene was investigated based on the following hypotheses: land use was important only in the southernmost regions, while elsewhere climate was the main driver modulated by changes in fuel type. BB was reconstructed by means of 88 sedimentary charcoal records divided into six dif- ferent site clusters. A statistical approach was used to explore the relative contribu- tion of (a) pollen‐based mean July/summer temperature and mean annual precipitation reconstructions, (b) an independent model‐based scenario of past land use (LU), and (c) pollen‐based reconstructions of plant functional types (PFTs) on BB. Our hypotheses were tested with: (a) a west‐east northern boreal sector with changing climatic conditions and a homogeneous vegetation, and (b) a north‐south European boreal sector characterized by gradual variation in both climate and vege- tation composition. The processes driving BB in boreal forests varied from one region to another during the Holocene. However, general trends in boreal biomass burning were primarily controlled by changes in climate (mean annual precipitation in Alaska, northern Quebec, and northern Fennoscandia, and mean July/summer temperature in central Canada and central Fennoscandia) and, secondarily, by fuel composition (BB positively correlated with the presence of boreal needleleaf ever- green trees in Alaska and in central and southern Fennoscandia). Land use played only a marginal role. A modification towards less flammable tree species (by promot- ing deciduous stands over fire‐prone conifers) could contribute to reduce circumbo- real wildfire risk in future warmer periods.