The result of 344 radiocarbon-dated megafossils is here presented and discussed. This study aims ... more The result of 344 radiocarbon-dated megafossils is here presented and discussed. This study aims at elucidating early- to mid-Holocene forest-line and climate dynamics in the southern Scandes along a present gradient of decreasing forest-line elevations. Around 9.5 calibrated ka before present (BP), pine suddenly established vertical belts of at least 200 m. These represent the highest pine-forests during the Holocene, ca. 210–170 m higher than today when corrected for land uplift. By this, summer temperatures at least 1–1.3°C warmer than today are indicated for the early Holocene thermal maximum around 8.5–9.5 cal. ka BP. The most pronounced warming occurred in Jotunheimen, the highest mountain range in Scandinavia, because of an amplified ‘Massenerhebung’ effect. Megafossils show the establishment of birch-forests above pine-forests already from the early Holocene. Pine-forests started their decline in the early Holocene and became replaced by the less warmth-demanding birch-forests. Pine megafossil results and pollen studies from the same areas show that cooling around 8.5 cal. ka BP caused a significant decrease in pine pollen production whereas pine-forest-lines were more or less unaffected. In the following period of about 2000 years, the high-altitudinal pine-forests could hardly be detected in pollen diagrams. This shows how strongly past temperatures influenced on the pollen production of individuals and how this might obscure pollen-based reconstructions of past vegetation. To be able to correct for this error, there is a need for establishing exact present-day relationships between temperature and pollen production of prolific pollen producers.
... The Holocene Thermal Maximum is indicated around ca 7.87.3 ka cal BP showing a chironomid-in... more ... The Holocene Thermal Maximum is indicated around ca 7.87.3 ka cal BP showing a chironomid-inferred July mean of at least 11 °C. This is ca 3 °C warmer than today. ... The calibrated dates in brackets show dates with maximum probability and are used in influx estimates. ...
Nord. J. Bot. - Section of geobotany Osmunda regalis in the early Holocene of Western NorwayHilar... more Nord. J. Bot. - Section of geobotany Osmunda regalis in the early Holocene of Western NorwayHilary H. Birks and Aage Paus Birks, H. H. & Paus, Aa. 1991. ... HH Birks and Aa. Paus, Botanical Institute, University of Bergen, Allkgaten 41, N-SO07 Bergen, Norway. Introduction ...
... of Tromsra, Lars Th~rings veg 10, N-9006 Troms~, Norway J. MANGERUD Department of Geology, Un... more ... of Tromsra, Lars Th~rings veg 10, N-9006 Troms~, Norway J. MANGERUD Department of Geology, University of Bergen, Allbgaten 41, N-5007 Bergen, Norway J. Y ... I: Late Weichselian environmental change in Western Norway (Hilary H. Birks, Aage Paus and J. I. Svendsen) ...
Abstract First results of investigations that include pollen and chemical analyses of lateglacial... more Abstract First results of investigations that include pollen and chemical analyses of lateglacial lake sediments from four sites in western Ireland are presented, and the evidence for environmental change from these and previously published studies is reviewed. Fresh evidence is presented for a period with a cold, arid, continental-type climate immediately after deglaciation. This period is informally defined as the Pre-interstadial. It is represented by a Pinus-Artemisia-Gramineae pollen assemblage, with a high proportion of long- ...
Page 1. JOURNAL OF QUATERNARY SCIENCE (1 989) 4 (3) 223-242 @ Longman Group UK Ltd 1989 0267-81 7... more Page 1. JOURNAL OF QUATERNARY SCIENCE (1 989) 4 (3) 223-242 @ Longman Group UK Ltd 1989 0267-81 79/89/04304223/$03.50 Late Weichselian vegetation, climate, and floral migration at Liastemmen, North Rogaland, south-western Norway ...
Pollen analysis from Sandvikvatn has elucidated the local Late Weichselian vegetational and clima... more Pollen analysis from Sandvikvatn has elucidated the local Late Weichselian vegetational and climatic history since deglaciation about 14,000 B.P. The pleniglacial period, the first of three climatic main periods and ending c. 13,600 B.P., is an Artemisia‐dominated pioneer vegetation on disturbed mineral soils. The Late Weichselian Interstadial (13,600‐11,000 B.P.) comprises a Salix‐shrub consolidation phase and, from 12,900 B.P., a birch‐forest optimum phase. In the Younger Dryas Stadial (11,000–10,100 B.P.) the Artemisia‐dominated pioneer vegetation returns. Three climatic oscillations are demonstrated at intervals of about 500 years within the Interstadial. The oldest two, about 12,500 and 12,000 B.P., could both have been connected with the ‘Older Dryas’. Cold winters and strong winds, causing soil erosion and drought, are suggested as important factors during the climatic periods unfavourable to woody vegetation. In the pleniglacial and Younger Dryas periods the winds are assumed to be katabatic. During the whole Late Weichselian southern species dominate locally. A northwards spread is demonstrated for the majority of the local late‐glacial taxa, including the endemic Primula scandinavica and also Papaver radicatum and Aconitum, both previously discussed as part of the hypothesis of Weichselian ice‐free refugia.
The result of 344 radiocarbon-dated megafossils is here presented and discussed. This study aims ... more The result of 344 radiocarbon-dated megafossils is here presented and discussed. This study aims at elucidating early- to mid-Holocene forest-line and climate dynamics in the southern Scandes along a present gradient of decreasing forest-line elevations. Around 9.5 calibrated ka before present (BP), pine suddenly established vertical belts of at least 200 m. These represent the highest pine-forests during the Holocene, ca. 210–170 m higher than today when corrected for land uplift. By this, summer temperatures at least 1–1.3°C warmer than today are indicated for the early Holocene thermal maximum around 8.5–9.5 cal. ka BP. The most pronounced warming occurred in Jotunheimen, the highest mountain range in Scandinavia, because of an amplified ‘Massenerhebung’ effect. Megafossils show the establishment of birch-forests above pine-forests already from the early Holocene. Pine-forests started their decline in the early Holocene and became replaced by the less warmth-demanding birch-forests. Pine megafossil results and pollen studies from the same areas show that cooling around 8.5 cal. ka BP caused a significant decrease in pine pollen production whereas pine-forest-lines were more or less unaffected. In the following period of about 2000 years, the high-altitudinal pine-forests could hardly be detected in pollen diagrams. This shows how strongly past temperatures influenced on the pollen production of individuals and how this might obscure pollen-based reconstructions of past vegetation. To be able to correct for this error, there is a need for establishing exact present-day relationships between temperature and pollen production of prolific pollen producers.
... The Holocene Thermal Maximum is indicated around ca 7.87.3 ka cal BP showing a chironomid-in... more ... The Holocene Thermal Maximum is indicated around ca 7.87.3 ka cal BP showing a chironomid-inferred July mean of at least 11 °C. This is ca 3 °C warmer than today. ... The calibrated dates in brackets show dates with maximum probability and are used in influx estimates. ...
Nord. J. Bot. - Section of geobotany Osmunda regalis in the early Holocene of Western NorwayHilar... more Nord. J. Bot. - Section of geobotany Osmunda regalis in the early Holocene of Western NorwayHilary H. Birks and Aage Paus Birks, H. H. & Paus, Aa. 1991. ... HH Birks and Aa. Paus, Botanical Institute, University of Bergen, Allkgaten 41, N-SO07 Bergen, Norway. Introduction ...
... of Tromsra, Lars Th~rings veg 10, N-9006 Troms~, Norway J. MANGERUD Department of Geology, Un... more ... of Tromsra, Lars Th~rings veg 10, N-9006 Troms~, Norway J. MANGERUD Department of Geology, University of Bergen, Allbgaten 41, N-5007 Bergen, Norway J. Y ... I: Late Weichselian environmental change in Western Norway (Hilary H. Birks, Aage Paus and J. I. Svendsen) ...
Abstract First results of investigations that include pollen and chemical analyses of lateglacial... more Abstract First results of investigations that include pollen and chemical analyses of lateglacial lake sediments from four sites in western Ireland are presented, and the evidence for environmental change from these and previously published studies is reviewed. Fresh evidence is presented for a period with a cold, arid, continental-type climate immediately after deglaciation. This period is informally defined as the Pre-interstadial. It is represented by a Pinus-Artemisia-Gramineae pollen assemblage, with a high proportion of long- ...
Page 1. JOURNAL OF QUATERNARY SCIENCE (1 989) 4 (3) 223-242 @ Longman Group UK Ltd 1989 0267-81 7... more Page 1. JOURNAL OF QUATERNARY SCIENCE (1 989) 4 (3) 223-242 @ Longman Group UK Ltd 1989 0267-81 79/89/04304223/$03.50 Late Weichselian vegetation, climate, and floral migration at Liastemmen, North Rogaland, south-western Norway ...
Pollen analysis from Sandvikvatn has elucidated the local Late Weichselian vegetational and clima... more Pollen analysis from Sandvikvatn has elucidated the local Late Weichselian vegetational and climatic history since deglaciation about 14,000 B.P. The pleniglacial period, the first of three climatic main periods and ending c. 13,600 B.P., is an Artemisia‐dominated pioneer vegetation on disturbed mineral soils. The Late Weichselian Interstadial (13,600‐11,000 B.P.) comprises a Salix‐shrub consolidation phase and, from 12,900 B.P., a birch‐forest optimum phase. In the Younger Dryas Stadial (11,000–10,100 B.P.) the Artemisia‐dominated pioneer vegetation returns. Three climatic oscillations are demonstrated at intervals of about 500 years within the Interstadial. The oldest two, about 12,500 and 12,000 B.P., could both have been connected with the ‘Older Dryas’. Cold winters and strong winds, causing soil erosion and drought, are suggested as important factors during the climatic periods unfavourable to woody vegetation. In the pleniglacial and Younger Dryas periods the winds are assumed to be katabatic. During the whole Late Weichselian southern species dominate locally. A northwards spread is demonstrated for the majority of the local late‐glacial taxa, including the endemic Primula scandinavica and also Papaver radicatum and Aconitum, both previously discussed as part of the hypothesis of Weichselian ice‐free refugia.
Uploads
Papers by Aage Paus