Historical charcoal burning and coppicing suppressed beech and increased forest vegetation heterogeneity

Abstract

AbstractQuestionsLong‐term legacies of historical human activities in temperate forests are increasingly recognised as an important driver of vegetation diversity and composition. To uncover centuries‐old legacies, novel approaches are, however, needed. Here, we combine anthracology of historical charcoal kilns and long‐term vegetation resurveys. We asked whether the historical coppicing oriented on charcoal production affected tree‐species composition and how the forest understorey vegetation changed after the coppicing was abandoned.LocationTemperate broadleaved forests in the Slovak Karst National Park, central Europe.MethodsTo explore the historical forest structure and long‐term changes in tree composition, we sampled charcoal remains from 28 historical kilns, identified the burnt tree taxa and estimated the original diameter of the burnt wood. To analyse the vegetation changes over the last four decades, we resurveyed plant composition of 60 quasi‐permanent plots established in 1975.ResultsHistorical charcoal burning was associated with coppicing, which decreased Fagus sylvatica dominance and favoured Quercus spp. in the tree layer. Several decades after the abandonment of coppicing, we observed the decline of Quercus spp. and spread of shade‐casting tree species with nutrient‐rich litter. This probably triggered the identified demise of light‐demanding species, the spread of nitrophytes and taxonomic homogenisation of the forest understorey.ConclusionsThe shift from historical coppicing to current high‐forest management was likely a main driver of the observed taxonomic homogenisation and decline of light‐demanding plants, as in other European lowland forests. Long‐term data from charcoal kilns showed, however, that closed‐canopy forests dominated by beech were historically more common and observed changes in vegetation thus represent a natural process. Findings also suggest that coppicing taking place over centuries enhanced diversity of forest understorey vegetation. Our novel approach combining a vegetation resurvey and charcoal kiln anthracology thus uncovered otherwise hidden links between current biological processes and the historical human legacies, with consequent important implications for nature protection and management.