Data for: Always on the tipping point – a search for signals of past societies and related peatland ecosystem critical transitions during the last 6500 years in N Poland
Description
We explored past critical transitions in a peatland located in N Poland using a densely dated (×44 14C dates & 210Pb), high-resolution multi-proxy profile. A 6450-year record was supported by a very robust age-depth model. Changes in land use, climate change and carbon sequestration in northern Poland were investigated using a range of biotic proxies. We determined critical transitions in the development of the mire which were dependent upon extrinsic drivers. The trophic status of mire shifted several times during the last 6.5 millennia. The pattern of changes suggests that it was very sensitive to different changes in the peatland basin. We identified several factors which may have driven transitions between the bog and fen state as a response to catchment hydrology changes largely driven by human impact which overlapped with periods of climate change. Based upon microcharcoal and pollen analyses, the threshold for fire intensity was estimated to be ca 7500 particles/cm2/year-1. We discovered that this burning was also an important tipping point for the divergence between plants positively related (e.g. human indicators and Carpinus) or negatively (e.g. Quercus) to fires. This community threshold was related to ecological changes related to the emergence and fall of subsequent human communities. The first pollen grains which indicate human activities in the deposits are dated to ca 6000 cal. BP, however, almost continuous human impact started since 5000 cal. BP. Then past societies actively affected the mire’s environment. The strongest signal comes from the Neolithic (Funnel Beaker Culture, Globular Amphora Culture and Corded Ware Culture), the Bronze Age (Iwno Culture and Trzciniec Culture), the Pre-Roman (La Tène) Period and the Roman Period (Oksywie Culture and Wielbark Culture). These past societies exploited natural resources and deforested the landscape while actively using fire. We inferred a distinct human influence since ca 5000 cal. BP (the Neolithic) until the Early Middle Ages with strong evidence during the Bronze Age and Roman Period which demonstrates the high importance of the area until the transition from the tribe period to the Polish state. The peatland possibly recorded several climatic shifts at: 6k (cool-warm), 4.2k (cool), 2.6k (wet shift) and 1.5k cal. BP (the Dark Ages - cold shift), however the climate change signal