From the Sellevollmyra bog at Andøya, northern Norway, a 440‐cm long peat core covering the last c. 7000 calendar years was examined for humification, loss‐on‐ignition, microfossils, macrofossils and tephra. The age model was based on a Bayesian wiggle‐match of 35 14C dates and two historically anchored tephra layers. Based on changes in lithology and biostratigraphical climate proxies, several climatic changes were identified (periods of the most fundamental changes in italics): 6410–6380, 6230–6050, 5730–5640, 5470–5430, 5340–5310, 5270–5100, 4790–4710, 4890–4820, 4380–4320, 4220–4120, 4000–3810, 3610–3580, 3370–3340 (regionally 2850–2750; in Sellevollmyra a hiatus between 2960–2520), 2330–2220, 1950, 1530–1450, 1150–840, 730? and c. 600? cal. yr BP. Most of these climate changes are known from other investigations of different palaeoclimate proxies in northern and middle Europe. Some volcanic eruptions seemingly coincide with vegetation changes recorded in the peat, e.g. about 5760 cal. yr BP; however, the known climatic deterioration at the time of the Hekla‐4 tephra layer started some decades before the eruption event.

Climate change with respect to summer temperature throughout the Holocene is inferred from oscillations in the local Pinus sylvestris, Alnus incana and Betula pubescens forest-lines, as recorded by fossil pollen and plant macrofossils in lake sediments at four altitudinal levels. Mt Skrubben (848 m a.s.l.), in Dividalen, was deglaciated down to below 280 m a.s.l. during 10 800-10 300 cal. yr BP. Betula pubescens established 10100 cal. yr BP at 280 m a.s.l. and expanded up to near the summit during the next 700 years. Birch woodland prevailed on the mountain plateau until 3300 cal. yr BP. Local Pinus sylvestris stands are recorded up to 400 m a.s.l. at 8450 cal. yr BP and >548 m a.s.l. about 8160 cal. yr BP. Alnus incana expanded from 400 to nearly 790 m a.s.l. during the period 7900-7600 cal. yr BP. The maximum forest distribution lasted until ca. 6000 cal. yr BP. Marked climatic deteriorations caused lowering of the forest-lines around 4600 and 3000 cal. yr BP. Reconstruction of the summer temperature indicated mean July temperatures at 400 m a.s.l. of 1.5-38C above the present during the period of maximum forest expansion, whereas >38C above the present temperature at 548 m a.s.l. This is in accordance with other regional temperature reconstructions from northern Europe.

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Vorren, K.‐D., Jensen, C. E. & Nilssen, E. 2012 (January): Climate changes during the last c. 7500 years as recorded by the degree of peat humification in the Lofoten region, Norway. Boreas, Vol. 41, pp. 13–30. 10.1111/j.1502‐3885.2011.00220.x. ISSN 0300‐9483. Two peat cores from two neighbouring bogs in Lofoten, northern Norway were densely AMS dated and analysed for humification. The two cores have been influenced by human agricultural impact, especially c. 1600 cal. a BP, which may have affected the local hydrology of the bogs. From 7400 cal. a BP onwards, 19 distinct wet‐shifts are recorded in the two cores. Eight or nine of these correspond chronologically to periods of low solar activity. This correlation is most convincing during the last 2000 years. Some wet‐shifts are connected with a solar low‐activity period during the Subboreal/Subatlantic transition, which in central Europe is dated at 2750–2565 cal. a BP. For Lofoten, the corresponding Subboreal/Subatlantic transition – or the wet‐shift marking this transition – is dated at c. 2600 cal. a BP. Some wet‐shifts occur just before or just after solar low‐activity periods, but only four of the nineteen wet‐shifts are clearly not temporally connected with periods of low solar activity. Compared with the wet‐shifts in NW European (mainly British Isles) bogs, there are more frequent wet‐shifts in northern Norway. Compared with other peat cores in northern Norway, especially for the interval 6500–5000 cal. a BP, Lofoten deviates by its lack of wet‐shifts. As in England, Scotland and Ireland, there is regional variability in the temporal formation of wet‐shifts in northern Norway.

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