Reflections of pre- and early-agrarian human impact in the pollen diagrams of Estonia

Abstract

High-resolution pollen profiles based on 30 cores taken from Estonian lake and mire deposits were used to reconstruct the extent and type of land-use over most of the Holocene. Biostratigraphical studies combining pollen records, archaeological investigations, conventional and accelerator mass spectrometry (AMS) radiocarbon dates and numerical analysis were used to detect human impact on the landscape and vegetation. Indications of human activity were traced back to the Mesolithic (9000–4900 cal. BC) and are reflected in the pollen diagram by a wide range of anthropogenic indicators, which constitute nearly half of the total pollen sum, together with high charcoal content. Human impact during the Mesolithic is also indicated by the rarefaction analysis, which shows a doubling of palynological diversity. The Neolithic (4900–1800 cal. BC) is regarded as a transitional period between the pre-agrarian Mesolithic and the agrarian Bronze Age (1800–500 cal. BC). Changes in vegetation composition attributed to Late Mesolithic (6400–4900 cal. BC) land-use were found in several of the sites investigated. Pollen records display the development and intensive use of a pastoral landscape in the Middle Neolithic (4150–3200 cal. BC), expressed in pollen diagrams as a drop in the frequencies of broad-leaved trees and an increase in Picea abies, herb pollen and palynological diversity and in some cases increase in charcoal frequencies. Primitive tillage probably occurred during the Middle Neolithic, at least in the alvar (flat terrain with a thin soil cover on carbonaceous bedrock) and coastal areas of Estonia. The earliest Cerealia pollen finds are dated to ca. 4000 cal. BC and represented by Avena-type and Hordeum-type pollen. During the Bronze Age, crop cultivation played an important role in the farming economy. The beginning of crop cultivation in Estonia was almost simultaneous with southern Sweden, but more than 1000 years earlier than in Finland. The adoption of arable farming in Estonia occurred much later than in southern Sweden.