Abstract Forest growth and development is a highly studied phenomenon in which humans have proven to be influential in shaping structure and composition. Delineating the long-term processes of human-environment interactions is crucial for understanding the history and trajectory of landscape formation and vegetation development. Yet, extensive knowledge of the ecological impacts of Stone Age anthropogenic activity is still lacking, particularly from Fennoscandian sites. A sediment core from South Mesna lake from the interior Scandinavian Peninsula was extracted to investigate the long-term evolutionary effects of human-environment interactions following deglaciation (c. 10,500 cal. BP) and initial colonization of the region. Analysis of the core involved microscopic/trace analytical methods, including geochemical analysis, stable isotope analysis, fecal biomarker analysis, and pollen analysis. The combined evidence demonstrates that anthropogenic impacts are prominent shapers of the ecological trajectory and landscape development of the region since the Early Neolithic (c. 5900 cal. BP), which has left a footprint on modern-day land cover. Significance Anthropogenic impacts on the environment have been observed to have had notable consequences on global and regional ecological trajectories and environmental development. Yet, how coupled human-environment interactions affect the long-term ecological complexion of boreal landscapes, such as those of the interior Scandinavian Peninsula, is not widely studied. This article presents evidence of early anthropogenic impacts to a forest’s ecology during the Holocene. Fecal biomarker and pollen analyses make it possible to provide micro-archaeological evidence of human activity and correlate it with noteworthy changes in forest structure. Our data points to a specific co-evolutionary forest development trajectory which is connected to millennial-scale human settlement patterns.
Understanding the climate of the last few centuries, including the ‘Little Ice Age’, may help us better understand modern-day natural climate variability and make climate predictions. The conventional view of the climate development during the last millennium has been that it followed the simple sequence of a ‘Mediaeval Warm Period’, a cool ‘Little Ice Age’ followed by warming in the later part of the nineteenth century and during the twentieth century. This view was mainly based on evidence from western Europe and the North Atlantic region. Recent research has, however, challenged this rather simple sequence of climate development in the recent past. Data presented here indicate that the rapid glacier advance in the early eighteenth century in southern Norway was mainly due to increased winter precipitation: mild, wet winters due to prevailing ‘positive North Atlantic Oscillation (NAO) weather mode’ in the first half of the eighteenth century; and not only lower summer temperatures. A comparison of recent mass-balance records and ‘Little Ice Age’ glacier fluctuations in southern Norway and the European Alps suggests that the asynchronous ‘Little Ice Age’ maxima in the two regions may be attributed to multidecadal trends in the north–south dipole NAO pattern.
Three equations derived from a close exponential glacier-climate relationship at the equilibrium-line altitude (ELA) of Norwegian glaciers have been utilized and implemented in a geographical information system (GIS). The first equation enables calculation of the minimum altitude of areas climatically suited for glacier formation at present, and is termed the altitude of instantaneous glacierization (AIG). Equation (2) is based on the ‘principle of terrain adaptation’, enabling quantification of the glacial buildup sensitivity (GBS) in an area. The third equation calculates the theoretical climatic (instrumental) temperature-precipitation ELA ( C TP-ELA) in presently non-glaciated areas by combining GBS with terrain altitude. The presented approach is primarily intended for palaeoclimatic analyses of former glacial records, and is tested here based on a plot of 122 temperature stations and 197 precipitation stations during the climate normal period 1961-1990 which has been recalculated to sea level using empirical vertical climatic gradients. These data were interpolated in the GIS using an ‘inverse square interpolation’ routine. Subsequently, the interpolated climatic data were recalculated to the terrain surface using vertical climatic gradients and a digital elevation model (DEM) of southern Norway (resolution 5 X 5 degree minutes/c. 1 km 2 ). The present glacier distribution in southern Norway is reproduced in great detail, and maps showing the modem GBS and C TP-ELA in non-glacierized areas of southern Norway are presented. Based on the GBS analysis, four scenarios with ELA depressions of 150 m (average ‘Little Ice Age’ conditions), 500 m (average coastal Younger Dryas conditions), 1000 m (suggested late Weichselian maximum coastal conditions) and 1500 m are shown.
The sedimentary record indicates several cirque glacier fluctuations during the Bolling (14.69-14.07 ka b2k) and Allerod (14.07-12.89 ka b2k) substages whereas the Younger Dryas (12.9-11.07 ka b2k) became progressively more stable. These results contradict results from southern Norway concerning timing and magnitude of glacier events during the last deglaciation. The moraine chronology shows several large advances suggested to have taken place prior to 17 ka b2k when the cirque glaciers coalesced. This indicates that the continental ice sheet in the nearby Andfjord was situated below a local bedrock threshold at c. 80 m a.s.l. during this period. Prior to or at the onset of the Bolling substage, large parts of the coalesced cirque glaciers melted away and resulted in three individual cirque glaciers. Exposure dating from the moraine chronology is in progress. The ongoing project will give new insight on the climate dynamics and variability related to the inflow of Atlantic water, sea-ice cover and moisture supply to coastal northern Norway during the Late Weichselian.
In 1895 a shed elk antler was found in a mire on a farm near Fluberg, in Søndre Land municipality in south-eastern Norway. The antler was first radiocarbon dated in 2008 and yielded the age 9,100 ± 50 BP (8,340 – 8,250 BC), which is the oldest dated elk remain from Norway. Elk (Alces alces L., 1758) are a pioneer colonising species; they were already established south of the ice front in Denmark and southern Sweden in the Late Glacial period. This antler shows that the species had arrived in south-eastern Norway in the late Preboreal period. This could tie in with the earliest arrival of elk once the colonizing routes from southern Sweden were established 9,300-9,200 BP. The antler is clearly of the palmate morph, and strongly resembles elk antlers found in Denmark and southern Sweden from the Late Glacial and Early Holocene periods. This find also reveals that the vegetation at the end of the Preboreal period suited large herbivores such as elk.
During the Lateglacial and early Holocene, abrupt, millennial-scale climatic variations are recorded in a wide range of high-resolution proxy records from marine and terrestrial archives in NW Europe. Our review of the evidence for these rapid climate events do not show an apparent link to possible forcing factors such as long-term, orbitally induced variations in solar radiation, short-term variations in solar activity as inferred from 14 C, atmospheric carbon dioxide concentration, or volcanic sulphate as recorded in the GISP2 ice-core record. There is, however, a remarkable degree of similarity with the number, duration and timing of episodes of increased flux of fresh water to the north Atlantic and Arctic Oceans from the Laurentide ice sheet and from the Baltic ice lake in SW Sweden. These freshwater outburst events occurred when continental runoff from the Laurentide ice sheet was rerouted from the Mississippi River to the Hudson River, St Lawrence River, Hudson Strait and along the Mackenzie River to the Atlantic and Arctic Oceans, and when the Baltic ice lake in SW Sweden drained to Skagerrak. Periods of increased freshwater flow to the North Atlantic and Arctic Oceans may thus provide a mechanism to explain the abrupt and significant Lateglacial and early Holocene climate events in NW Europe. The idea that freshwater outbursts might drive abrupt climate events is not new, but previous work may have underestimated the extent of support from proxy data and overestimated the influence of the Laurentide ice sheet.
Blockfields, weathering boundaries and marginal moraines have been mapped along a longitudinal transect from northern Andøya to Skånland in northern Norway. The degree of rock‐surface weathering above and below glacial trimlines, clay‐mineral assemblages and surface exposure dating based on in situ cosmogenic 10 Be have been used to reconstruct the vertical dimensions and timing of the Last Glacial Maximum (LGM) of the Scandinavian Ice Sheet in this region. The cosmogenic exposure dates suggest that the lower blockfield boundary/trimline along the Andøya‐Skånland transect represents the upper limit of the Late Weichselian ice sheet, with an average surface gradient of c . 9.5 m/km. The surface exposure dates from Andøya pre‐date the LGM, suggesting that the LGM ice sheet did not reach mountain plateaux at northwest Andøya. The results thus support evidence from lake sediment records that the northern tip of Andøya was not covered by the Scandinavian Ice Sheet during the LGM.
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