Biomass burning in the Carpathians

Angelica Feurdean1
1 Biodiversit├Ąt und Klima Forschungszentrum

V 5.5 in Climate and Environment of the last 130,000 years

18.09.2012, 10:30-10:50, H6

Fire is recognized as a critical process with significant impacts on biota and the atmosphere. Here I review micro- and macrocharcoal sedimentary records extracted from peat bogs and lakes at different elevations in the Carpathian region  in order to explore the patterns and the potential underlying mechanisms in biomass burning in this region during the last 15,000 years. Results from micro-charcoal and macro-charcoal data show similar trends in biomass burning and suggest that the major signal of both charcoal size-fragments relates mainly to local fires. Fire activity was low during the late glacial, attained maximum values in the early Holocene (11,700-8000 cal. yr BP), become lower than present during the mid-late Holocene (8000-1000 cal yr BP), and increased again over the last 1000 years. The reconstructed spatial trends in biomass burning display different degrees of heterogeneity through time. Generally, there was more spatial similarity in fire activity across the study region during the late glacial and early Holocene (15,000-8000 cal yr BP), followed by increased spatial heterogeneity from ca. 8000 cal yr BP onwards. Biomass burning appears to have been primarily modulated by climate during both the late glacial and Holocene, through its effect on vegetation productivity and therefore fuel availability (late glacial), and fuel structure, moisture and flammability (the Holocene). Onsite human activities are likely to have provided an extra ignition source already in the early Holocene. However, evidence suggest that anthropogenic activities have markedly altered the natural trends in biomass burning from about 3500 yr BP (lowlands) and over the last 1000 years (in the mountain environments), by either removing the biomass (in the lowlands) or igniting fire where it seldom occurs naturally (i.e., in the mountain environments). On the other hand, burning activity also appears coincident with significant changes in tree species compositions, indicating that fire has likely acted as a driving factor in forest dynamics. Results also suggest that peat deposits provide a more localized fire record than lakes, and that trends and patterns of change can be different even for sites situated close to each other.



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last modified 2012-07-26