In:
Biogeosciences, Copernicus GmbH, Vol. 17, No. 5 ( 2020-03-04), p. 1213-1230
Abstract:
Abstract. Wildfire occurrence is influenced by climate, vegetation and human
activities. A key challenge for understanding the risk of fires is quantifying the mediating effect of vegetation on fire
regimes. Here, we explore the relative importance of Holocene land cover,
land use, dominant functional forest type, and climate dynamics on biomass
burning in temperate and boreo-nemoral regions of central and eastern Europe
over the past 12 kyr. We used an extensive data set of Holocene pollen and
sedimentary charcoal records, in combination with climate simulations and
statistical modelling. Biomass burning was highest during the early Holocene
and lowest during the mid-Holocene in all three ecoregions (Atlantic, continental and boreo-nemoral) but was more spatially variable over the past 3–4 kyr. Although climate explained a
significant variance in biomass burning during the early Holocene, tree
cover was consistently the highest predictor of past biomass burning over
the past 8 kyr. In temperate forests, biomass burning was high at
∼45 % tree cover and decreased to a minimum at between 60 % and
70 % tree cover. In needleleaf-dominated forests, biomass burning was
highest at ∼ 60 %–65 % tree cover and steeply declined at
〉65 % tree cover. Biomass burning also increased when arable
lands and grasslands reached ∼ 15 %–20 %, although this
relationship was variable depending on land use practice via ignition
sources, fuel type and quantities. Higher tree cover reduced the amount of
solar radiation reaching the forest floor and could provide moister, more
wind-protected microclimates underneath canopies, thereby decreasing fuel
flammability. Tree cover at which biomass burning increased appears to be
driven by warmer and drier summer conditions during the early Holocene and
by increasing human influence on land cover during the late Holocene. We suggest that long-term fire hazard
may be effectively reduced through land cover management, given that land
cover has controlled fire regimes under the dynamic climates of the
Holocene.
Type of Medium:
Online Resource
ISSN:
1726-4189
DOI:
10.5194/bg-17-1213-2020
DOI:
10.5194/bg-17-1213-2020-supplement
Language:
English
Publisher:
Copernicus GmbH
Publication Date:
2020
detail.hit.zdb_id:
2158181-2
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