Human ecodynamics in the north-west coast of Finland 10,000-2000 years ago

High-quality palaeoenvironmental proxies and well-preserved archaeological record make Fennoscandia as an excellent area for the studies of long-term human-environment interaction in high-latitude settings. Here, we use palaeoenvironmental data and temporal frequency distributions of 754 shoreline dated hunter-gatherer sites to analyse the relationship between environmental changes and hunter-gatherer population dynamics, mobility, social organisation, and conflicts in the Baltic Sea coast of western Finland. Our results suggest, firstly, that hunter-gatherer population dynamics were strongly influenced by changes in the productivity of terrestrial and marine environments. Secondly, the degree of residential mobility, as indicated by the frequency of house pit sites, was correlated with population size. Thirdly, large villages and large co-residential units were tightly associated with the highest population size and their frequency dropped sharply when population size started to decrease. Fourthly, intensity of conflicts, as indicated by frequency of defensive structures, was the highest slightly after the highest population sizes, when environmental productivity had started to decline. Increased conflicts were probably caused by the imbalance between human population and its resources. Lastly, dramatic population crash (76% within 200 years) occurred just after the intensity peak in conflicts. The crash was partly density dependent (conflicts) and partly density independent phenomenon as it coincided with the onset of the Late Holocene acceleration in the cooling trend in climate. Continuing decline in the environmental productivity during the Late Holocene did not allow hunter-gatherer population to recover from the collapse. All this highlights the importance of environmental forcing on hunter-gatherer populations in northern Europe.Peer reviewe