Biomass burning fuel consumption rates: a field measurement database

[摘要] Landscape fires show large variability in the amount of biomass or fuelconsumed per unit area burned. Fuel consumption (FC) depends on the biomassavailable to burn and the fraction of the biomass that is actually combusted,and can be combined with estimates of area burned to assess emissions. Whileburned area can be detected from space and estimates are becoming morereliable due to improved algorithms and sensors, FC is usually modeled ortaken selectively from the literature. We compiled the peer-reviewedliterature on FC for various biomes and fuel categories to understand FC andits variability better, and to provide a database that can be used toconstrain biogeochemical models with fire modules. We compiled in total 77studies covering 11 biomes including savanna (15 studies, average FC of4.6 t DM (dry matter) ha⁻¹ with a standard deviation of 2.2), tropicalforest (n = 19, FC = 126 ± 77), temperate forest (n = 12,FC = 58 ± 72), boreal forest (n = 16, FC = 35 ± 24),pasture (n = 4, FC = 28 ± 9.3), shifting cultivation (n = 2,FC = 23, with a range of 4.0–43), crop residue (n = 4,FC = 6.5 ± 9.0), chaparral (n = 3, FC = 27 ± 19),tropical peatland (n = 4, FC = 314 ± 196), boreal peatland(n = 2, FC = 42 [42–43]), and tundra (n = 1, FC = 40). Withinbiomes the regional variability in the number of measurements was sometimeslarge, with e.g. only three measurement locations in boreal Russia and 35sites in North America. Substantial regional differences in FC were foundwithin the defined biomes: for example, FC of temperate pine forests in theUSA was 37% lower than Australian forests dominated by eucalypt trees.Besides showing the differences between biomes, FC estimates were alsogrouped into different fuel classes. Our results highlight the largevariability in FC, not only between biomes but also within biomes and fuelclasses. This implies that substantial uncertainties are associated withusing biome-averaged values to represent FC for whole biomes. Comparing thecompiled FC values with co-located Global Fire Emissions Database version 3(GFED3) FC indicates that modeling studies that aim to represent variabilityin FC also within biomes, still require improvements as they havedifficulty in representing the dynamics governing FC.

[学科分类] 地球化学与岩石