Soil charcoal elucidates the role of humans in the development of landscape of extreme biodiversity

Abstract

The south-western White Carpathians (Czech Republic, Slovakia) are one of the few places in low-elevation Central Europe where a diverse landscape, including extremely species rich meadows, scattered oak trees, and mixed oak woodlands, has escaped modern transformation. We studied C14-dated and taxonomically identified macroscopic soil charcoal record to elucidate the genesis of this landscape. Thirteen soil profiles were sampled in grasslands along a gradient of elevation and history of human settlement. We identified clear pattern in the taxonomic composition of woody soil charcoal and anthracomass along this gradient, which we ascribe to different pathways of landscape development. Charcoal assemblages of chernozem-like soils in the promontories of the mountain range have a low anthracomass and are dominated by heliophilous and semishade species (Quercus, Pinus), with the oldest charcoals dated to pre-Neolithic times. Soils of the middle elevations have a high anthracomass and often show pronounced differences in charcoal composition at different soil depths; the oldest charcoal samples date back between the Neolithic and Early Middle Ages, and heliophilous species increase towards the topsoil. The soil of the summit area shows a medium anthracomass and charcoal assemblage dominated by shade-tolerant trees; the charcoal dates from the Middle Ages. Our results suggest continuity of an open to semiopen landscape in lower elevations of the White Carpathians, whereas middle and higher elevations experienced a forested period. Humans and fire played an important role in landscape development, as indicated by both soil charcoal and available palaeoecological and archaeological evidence. Local meadows with extremely high biodiversity thus appear to be a continuation of an ancient forest-steppe-like ecosystem.