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Charcoal fragments in soils are useful to reconstruct past vegetation because the level of preservation is often good enough to determine the tree genus. All forest ecosystems have the potential to burn as a result of naturally occurring or human-induced fires. Forest fires are coupled to climate and are a not-negligible factor of pedogenesis in Mediterranean areas, where they occur frequently. Furthermore, soil organic matter (SOM) is prone to undergo peculiar changes due to forest fires, both in terms of quantity and quality. A soil sequence along an elevational gradient ranging from Mediterranean to subalpine climate zones on slopes of Mt. Etna (Sicily, Italy) was investigated in respect of soil organic C and charcoal. The amount of charcoal and the identification of charred species gave an indication of the fire frequency and vegetation changes that have occurred in the past. The distribution into labile and stable organic fractions provided insight into the stabilisation and turnover mechanisms of SOM. The stable organic matter fraction was measured as the residue of a H2O2 treatment. The soils along the altitudinal sequence are variations of Vitric Andosols that developed on a single trachy-basaltic lava flow having an age of 10-15 ky BP. Maquis vegetation dominates at the lower sites of the toposequence, followed by oak- and chestnut-forests at mid elevations, and pine-forest at the highest-elevated sites. Charcoals are older at higher elevations (ages of up to 1.5 ky cal BP). Here, the vegetation type has not changed over the last > 1000 years, as all charcoal pieces were identified as Pinus nigra. Charred material at the lower sites could be identified as particles of deciduous shrubs, Quercus, Castanea sativa, Lonicera implexa and Cytisus spp. with mostly a modern age up to about 300 y cal BP. A similar finding was obtained for the stable (H2O2 resistant) SOM. Very high ages for this fraction were found at the highest elevations where it had an age of up t

Peat and lake sediments as well as a nearby soil catena were sampled to reconstruct the environmental history of a small infilled lake basin (mire) in the central alpine foreland of Switzerland. Soil evolution is best regarded as discontinuous over time and conceptualised by ‘progressive’ or ‘regressive’ process phases. We analysed the surrounding soils and used corresponding pedosignatures in the mire sediments to characterise notable phases of erosion and deposition. We assumed that the mire sediments would reflect these phases, that elemental composition (major and minor compounds) and rare earth elements (REEs) would allow us to differentiate past processes and that progressive and regressive phases of soil development can be discerned. Although radiocarbon ages are equivocal, it appears from pollen analyses that a lake was present here by c. 45 ka BP. After the retreat of the glacier from this area following the LGM, continuous sedimentation occurred until a mire developed during Pleistocene-Holocene transition. This transition period was accompanied by more intense erosion, as characterised by chemical signatures. A stable phase developed between c. 10-5 ka BP giving rise to progressive soil evolution. Between 5 and 4 ka BP, evidence appears for several erosional phases, predominantly detectable at the margin of the mire. These erosion phases, coupled with accumulation in the mire, are even more evident after 4 ka BP and especially after 2.1 ka BP. Based on soil investigations, elemental fluxes are detected along the slopes with distinct accumulations at the footslope. Evidence for anthropogenic influences and subsequent regressive soil formation phases appear in this pre-alpine landscape about 5 ka BP (Neolithic/Early Bronze Age), which appears to intensify after 2.1 ka BP (Roman period to present). Multi-elemental signatures enabled us to identify the important geochemical processes that have occurred here. Together with radiocarbon and pollen analyses, we p