Brigitta Ammann
Datos Biográficos
| ID | 4783399 |
|---|---|
| NOMBRE | Brigitta Ammann |
| NOMBRES | Brigitta |
| APELLIDO | Ammann |
| FIRMA | AMMANN B |
| AFILIACIONES | University of Bern |
| ORCID | 0000-0001-6123-6357 |
| VERIFICADO | Sí |
| TOTAL DE OBRAS | 24 |
| TOTAL DE CITAS | 224 |
| TOTAL COMO AUTOR | 24 |
| TOTAL COMO EDITOR | 0 |
| PRIMER AÑO DE PUBLICACIÓN | 1986 |
| AÑO MÁS RECIENTE DE PUBLICACIÓN | 2016 |
| ÍNDICE H | 9 |
Gerhard Lang (21.10.1924–19.6.2016)
In Memoriam
Herbert E Wright Jr was one of the foremost Quaternary scientists of the last century. He made wide ranging contributions to our understanding of the late-Quaternary of North and South America, Europe, Asia and Africa. This was based largely on reconstructing palaeoenvironments from lake sediments and included the important implications for glacial, vegetational, fire and climatic history, geoarchaeology and conservation. Many of his inter-discip…
Palynological richness and evenness
The potential of stomata analysis in conifers to estimate presence of conifer trees
Biotic responses to rapid warming at Termination 1a at Gerzensee (Central Europe) – Hypotheses about succession, albedo, soils, lake development, and ecological interactions
Effects of climatic change and bog development on Holocene tufa formation in the Lorze Valley (central Switzerland)
A massive tufa complex in the lower Lorze Valley (550 m a.s.l., north-central Switzerland) formed between 9000 and 5000 cal. yr BP. In the plain 4 km southeast of the complex lies Neugrundmoor (830 m a.s.l.), a mire in the hydrologic recharge area of the springs responsible for the tufa formation. Here we address an earlier, untested hypothesis that the transition of Neugrundmoor from fen to raised bog caused the end of the tufa formation, by mea…
Annual pollen traps reveal the complexity of climatic control on pollen productivity in Europe and the Caucasus
Annual PAR (pollen accumulation rates; grains cm−2 year−1) were studied with modified Tauber traps situated in ten regions, in Poland (Roztocze), the Czech Republic (two regions in Krkonoše, two in Šumava), Switzerland (4 regions in the Alps), and Georgia (Lagodekhi). The time-series are 10–16 years long, all ending in 2007. We calculated correlations between pollen data and climate. Pollen data are PAR summarized per region (4–7 traps selected p…
A new Late-glacial and Holocene record of vegetation and fire history from Lago del Greppo, northern Apennines, Italy
Testing the influence of climate, human impact and fire on the Holocene population expansion of Fagus sylvatica in the southern Prealps (Italy)
This study addresses the timing and causes of the Holocene population expansion of Fagus sylvatica at two sites in the southern Prealps (Italy): Lago di Fimon and Lago Piccolo di Avigliana. At both sites pollen and microcharcoal have been analysed at high temporal resolution. The impact of humans and of fire on the forest dynamics is tested by means of time-series analysis and the influence of climatic change has been inferred from summer tempera…
Biotic response to rapid climatic changes during the Late Glacial
Organisms can respond to rapid climatic changes in three ways: 1) adaptation by evolution, affecting physiology and morphology), 2) migration and population dynamics including biogeographical changes) and 3) extinction local or global). Here, the focus is on examples of the second type. Organisms, whether algae, trees, or animals, find their ecological niches in a multi- dimensional space of gradients such as temperature winter, summer, means or …
Years of vegetation and settlement history from Egelsee (Menzingen, central Switzerland)
Past vegetation dynamics and human impact from the Lateglacial to the present are reconstructed by pollen analysis of a core 12 m long from the raised bog Egelsee, central Switzerland (770 m a.s.l.). The depth—age model of the core is based on 29 AMS 14 C dates. The oldest dated macrofossil has an age of 13 080 ± 105 radiocarbon yr BP (15 370 cal. yr BP); extrapolation leads to a basal age of the core of 16 200 cal. yr BP. The biostratigraphy sho…
Forest dynamics in the Pfyn forest in recent centuries (Valais, Switzerland, Central Alps)
Pinus sylvestris is co-dominant in many areas of eastern and northern Europe. In Switzerland, the Pfyn forest is considered to be the largest natural forest of Pinus sylvestris. Its development under changing land use during recent centuries is largely unknown. Of particular interest is the interaction between pine and oak, for it has been suggested that oak has benefited from the strong decline in economic uses of the forest such as pasturing, l…
Fire ecology north and south of the Alps since the last ice age
Wildfires are very rare in central Europe, which is probably why fire effects on vegetation have been neglected by most central European ecologists and palaeoecologists. Presently, reconstructions of fire history and fire ecology are almost absent. We analysed sediment cores from lakes on the Swiss Plateau (Lobsigensee and Soppensee) for pollen and charcoal to investigate the relationship between vegetation and fire. Microscopic charcoal evidence…
Early-Holocene afforestation processes in the lower subalpine belt of the Central Swiss Alps as inferred from macrofossil and pollen records
To reconstruct the vegetation history of the Upper Engadine, continuous sediment cores covering the past 11 800 years from Lej da Champfer and Lej da San Murezzan (Upper Engadine Valley, c. 1800 m a.s.l., southeastern Switzerland) have been analysed for pollen and plant macrofossils. The chronologies of the cores are based on 16 and 22 radiocarbon dates, respectively. The palaeobotanical records of both lakes are in agreement for the Holocene, bu…
Human impact during the Bronze Age on the vegetation at Lago Lucone (northern Italy)
Climatic change and contemporaneous land-use phases north and south of the Alps 2300 BC to 800 AD
Lateglacial and Holocene vegetation belts in the Pirin Mountains (southwestern Bulgaria)
Pollen stratigraphy of a core 270 cm long from Lake Dalgoto at 2310 m in the Northern Pirin Mountains, southern Bulgaria, was treated by optimal partitioning and compared to a broken-stick model to reveal statistically significant pollen zones. The vegetational reconstructions presented here are based on pollen percentages and pollen influx, on comparisons of modern and fossil pollen spectra, and on macrofossil dates from other sites in the mount…
Middle to Late Holocene vegetation history of the Upper Engadine (Swiss Alps)
A palaeoecological attempt to classify fire sensitivity of trees in the southern Alps
Using pollen percentages and charcoal influx to reconstruct the Holocene vegetation and fire history, we differentiate six possible responses of plants to fire of medium and high frequency: fire-intolerant, fire damaged, fire-sensitive, fire-indifferent, fire-enhanced and fire-adapted. The fire sensitivity of 17 pollen types, representing 20 woody species in the southern Alps, is validated by comparison with today's ecological studies of plant ch…
Influence of human impact and bedrock differences on the vegetational history of the Insubrian Southern Alps
Long-term forest fire ecology and dynamics in southern Switzerland
1 Pollen and charcoal analysis at two lakes in southern Switzerland revealed that fire has had a prominent role in changing the woodland composition of this area for more than 7000 years. 2 The sediment of Lago di Origlio for the period between 5100 and 3100 bc cal. was sampled continuously with a time interval of about 10 years. Peaks of charcoal particles were significantly correlated with repeated declines in pollen of Abies, Hedera, Tilia, Ul…
Pollen and charcoal in lake sediments compared with historically documented forest fires in southern Switzerland since AD 1920
Charcoal in unlaminated sediments dated by 210 Pb was analysed by the pollen-slide and thin-section methods. The results were compared with the number and area of forest fires on different spatial scales in the area around Lago di Origlio as listed in the wildfire database of southern Switzerland since AD 1920. The influx of the number of charcoal particles > 75 μm 2 in pollen slides correlates well with the number of annual forest fires recorded…
Atmospheric Radiocarbon at the End of the Last Glacial
The main purpose of this work is to reconstruct the atmospheric Δ 14 C in the glacial-postglacial transition, 14,000 – 10,000 BP, a range not covered by the tree-ring calibration curve. We measured 14 C/ 12 C ratios on series of terrestrial macrofossils from sediments of two Swiss lakes. We selected exclusively plant remains of recognizable terrestrial origin that are not affected by hard water and thus reflect atmospheric 14 C concentration. Due…
C Dating of Plant Macrofossils in Lake Sediment
Macrofossils of terrestrial plants have been picked from a sediment core taken in Lake Lobsigen, a small lake on the Western Swiss Plateau. The sediments were previously analyzed for pollen composition, plant and animal macrofossils, and stable isotopes. Plant macrofossils were selected near pollen zone boundaries in Late Glacial and early Postglacial sediment for 14 C dating by AMS. In the same lake carbonate and gyttja (aquatic plant) samples w…
Middle to Late Holocene vegetation history of the Upper Engadine (Swiss Alps)
Pollen and charcoal in lake sediments compared with historically documented forest fires in southern Switzerland since AD 1920
Charcoal in unlaminated sediments dated by 210 Pb was analysed by the pollen-slide and thin-section methods. The results were compared with the number and area of forest fires on different spatial scales in the area around Lago di Origlio as listed in the wildfire database of southern Switzerland since AD 1920. The influx of the number of charcoal particles > 75 μm 2 in pollen slides correlates well with the number of annual forest fires recorded…
Influence of human impact and bedrock differences on the vegetational history of the Insubrian Southern Alps
Human impact during the Bronze Age on the vegetation at Lago Lucone (northern Italy)
A palaeoecological attempt to classify fire sensitivity of trees in the southern Alps
Using pollen percentages and charcoal influx to reconstruct the Holocene vegetation and fire history, we differentiate six possible responses of plants to fire of medium and high frequency: fire-intolerant, fire damaged, fire-sensitive, fire-indifferent, fire-enhanced and fire-adapted. The fire sensitivity of 17 pollen types, representing 20 woody species in the southern Alps, is validated by comparison with today's ecological studies of plant ch…
Annual pollen traps reveal the complexity of climatic control on pollen productivity in Europe and the Caucasus
Annual PAR (pollen accumulation rates; grains cm−2 year−1) were studied with modified Tauber traps situated in ten regions, in Poland (Roztocze), the Czech Republic (two regions in Krkonoše, two in Šumava), Switzerland (4 regions in the Alps), and Georgia (Lagodekhi). The time-series are 10–16 years long, all ending in 2007. We calculated correlations between pollen data and climate. Pollen data are PAR summarized per region (4–7 traps selected p…
A new Late-glacial and Holocene record of vegetation and fire history from Lago del Greppo, northern Apennines, Italy
Fire ecology north and south of the Alps since the last ice age
Wildfires are very rare in central Europe, which is probably why fire effects on vegetation have been neglected by most central European ecologists and palaeoecologists. Presently, reconstructions of fire history and fire ecology are almost absent. We analysed sediment cores from lakes on the Swiss Plateau (Lobsigensee and Soppensee) for pollen and charcoal to investigate the relationship between vegetation and fire. Microscopic charcoal evidence…
C Dating of Plant Macrofossils in Lake Sediment
Macrofossils of terrestrial plants have been picked from a sediment core taken in Lake Lobsigen, a small lake on the Western Swiss Plateau. The sediments were previously analyzed for pollen composition, plant and animal macrofossils, and stable isotopes. Plant macrofossils were selected near pollen zone boundaries in Late Glacial and early Postglacial sediment for 14 C dating by AMS. In the same lake carbonate and gyttja (aquatic plant) samples w…
The potential of stomata analysis in conifers to estimate presence of conifer trees
Palynological richness and evenness
Atmospheric Radiocarbon at the End of the Last Glacial
The main purpose of this work is to reconstruct the atmospheric Δ 14 C in the glacial-postglacial transition, 14,000 – 10,000 BP, a range not covered by the tree-ring calibration curve. We measured 14 C/ 12 C ratios on series of terrestrial macrofossils from sediments of two Swiss lakes. We selected exclusively plant remains of recognizable terrestrial origin that are not affected by hard water and thus reflect atmospheric 14 C concentration. Due…
Early-Holocene afforestation processes in the lower subalpine belt of the Central Swiss Alps as inferred from macrofossil and pollen records
To reconstruct the vegetation history of the Upper Engadine, continuous sediment cores covering the past 11 800 years from Lej da Champfer and Lej da San Murezzan (Upper Engadine Valley, c. 1800 m a.s.l., southeastern Switzerland) have been analysed for pollen and plant macrofossils. The chronologies of the cores are based on 16 and 22 radiocarbon dates, respectively. The palaeobotanical records of both lakes are in agreement for the Holocene, bu…
Testing the influence of climate, human impact and fire on the Holocene population expansion of Fagus sylvatica in the southern Prealps (Italy)
This study addresses the timing and causes of the Holocene population expansion of Fagus sylvatica at two sites in the southern Prealps (Italy): Lago di Fimon and Lago Piccolo di Avigliana. At both sites pollen and microcharcoal have been analysed at high temporal resolution. The impact of humans and of fire on the forest dynamics is tested by means of time-series analysis and the influence of climatic change has been inferred from summer tempera…
Lateglacial and Holocene vegetation belts in the Pirin Mountains (southwestern Bulgaria)
Pollen stratigraphy of a core 270 cm long from Lake Dalgoto at 2310 m in the Northern Pirin Mountains, southern Bulgaria, was treated by optimal partitioning and compared to a broken-stick model to reveal statistically significant pollen zones. The vegetational reconstructions presented here are based on pollen percentages and pollen influx, on comparisons of modern and fossil pollen spectra, and on macrofossil dates from other sites in the mount…
In Memoriam
Herbert E Wright Jr was one of the foremost Quaternary scientists of the last century. He made wide ranging contributions to our understanding of the late-Quaternary of North and South America, Europe, Asia and Africa. This was based largely on reconstructing palaeoenvironments from lake sediments and included the important implications for glacial, vegetational, fire and climatic history, geoarchaeology and conservation. Many of his inter-discip…
Years of vegetation and settlement history from Egelsee (Menzingen, central Switzerland)
Past vegetation dynamics and human impact from the Lateglacial to the present are reconstructed by pollen analysis of a core 12 m long from the raised bog Egelsee, central Switzerland (770 m a.s.l.). The depth—age model of the core is based on 29 AMS 14 C dates. The oldest dated macrofossil has an age of 13 080 ± 105 radiocarbon yr BP (15 370 cal. yr BP); extrapolation leads to a basal age of the core of 16 200 cal. yr BP. The biostratigraphy sho…
Forest dynamics in the Pfyn forest in recent centuries (Valais, Switzerland, Central Alps)
Pinus sylvestris is co-dominant in many areas of eastern and northern Europe. In Switzerland, the Pfyn forest is considered to be the largest natural forest of Pinus sylvestris. Its development under changing land use during recent centuries is largely unknown. Of particular interest is the interaction between pine and oak, for it has been suggested that oak has benefited from the strong decline in economic uses of the forest such as pasturing, l…
C Dating of Plant Macrofossils in Lake Sediment
Macrofossils of terrestrial plants have been picked from a sediment core taken in Lake Lobsigen, a small lake on the Western Swiss Plateau. The sediments were previously analyzed for pollen composition, plant and animal macrofossils, and stable isotopes. Plant macrofossils were selected near pollen zone boundaries in Late Glacial and early Postglacial sediment for 14 C dating by AMS. In the same lake carbonate and gyttja (aquatic plant) samples w…
Atmospheric Radiocarbon at the End of the Last Glacial
The main purpose of this work is to reconstruct the atmospheric Δ 14 C in the glacial-postglacial transition, 14,000 – 10,000 BP, a range not covered by the tree-ring calibration curve. We measured 14 C/ 12 C ratios on series of terrestrial macrofossils from sediments of two Swiss lakes. We selected exclusively plant remains of recognizable terrestrial origin that are not affected by hard water and thus reflect atmospheric 14 C concentration. Due…
Pollen and charcoal in lake sediments compared with historically documented forest fires in southern Switzerland since AD 1920
Charcoal in unlaminated sediments dated by 210 Pb was analysed by the pollen-slide and thin-section methods. The results were compared with the number and area of forest fires on different spatial scales in the area around Lago di Origlio as listed in the wildfire database of southern Switzerland since AD 1920. The influx of the number of charcoal particles > 75 μm 2 in pollen slides correlates well with the number of annual forest fires recorded…
Long-term forest fire ecology and dynamics in southern Switzerland
1 Pollen and charcoal analysis at two lakes in southern Switzerland revealed that fire has had a prominent role in changing the woodland composition of this area for more than 7000 years. 2 The sediment of Lago di Origlio for the period between 5100 and 3100 bc cal. was sampled continuously with a time interval of about 10 years. Peaks of charcoal particles were significantly correlated with repeated declines in pollen of Abies, Hedera, Tilia, Ul…
A palaeoecological attempt to classify fire sensitivity of trees in the southern Alps
Using pollen percentages and charcoal influx to reconstruct the Holocene vegetation and fire history, we differentiate six possible responses of plants to fire of medium and high frequency: fire-intolerant, fire damaged, fire-sensitive, fire-indifferent, fire-enhanced and fire-adapted. The fire sensitivity of 17 pollen types, representing 20 woody species in the southern Alps, is validated by comparison with today's ecological studies of plant ch…
Influence of human impact and bedrock differences on the vegetational history of the Insubrian Southern Alps
Climatic change and contemporaneous land-use phases north and south of the Alps 2300 BC to 800 AD
Lateglacial and Holocene vegetation belts in the Pirin Mountains (southwestern Bulgaria)
Pollen stratigraphy of a core 270 cm long from Lake Dalgoto at 2310 m in the Northern Pirin Mountains, southern Bulgaria, was treated by optimal partitioning and compared to a broken-stick model to reveal statistically significant pollen zones. The vegetational reconstructions presented here are based on pollen percentages and pollen influx, on comparisons of modern and fossil pollen spectra, and on macrofossil dates from other sites in the mount…
Middle to Late Holocene vegetation history of the Upper Engadine (Swiss Alps)
Fire ecology north and south of the Alps since the last ice age
Wildfires are very rare in central Europe, which is probably why fire effects on vegetation have been neglected by most central European ecologists and palaeoecologists. Presently, reconstructions of fire history and fire ecology are almost absent. We analysed sediment cores from lakes on the Swiss Plateau (Lobsigensee and Soppensee) for pollen and charcoal to investigate the relationship between vegetation and fire. Microscopic charcoal evidence…
Early-Holocene afforestation processes in the lower subalpine belt of the Central Swiss Alps as inferred from macrofossil and pollen records
To reconstruct the vegetation history of the Upper Engadine, continuous sediment cores covering the past 11 800 years from Lej da Champfer and Lej da San Murezzan (Upper Engadine Valley, c. 1800 m a.s.l., southeastern Switzerland) have been analysed for pollen and plant macrofossils. The chronologies of the cores are based on 16 and 22 radiocarbon dates, respectively. The palaeobotanical records of both lakes are in agreement for the Holocene, bu…
Human impact during the Bronze Age on the vegetation at Lago Lucone (northern Italy)
Forest dynamics in the Pfyn forest in recent centuries (Valais, Switzerland, Central Alps)
Pinus sylvestris is co-dominant in many areas of eastern and northern Europe. In Switzerland, the Pfyn forest is considered to be the largest natural forest of Pinus sylvestris. Its development under changing land use during recent centuries is largely unknown. Of particular interest is the interaction between pine and oak, for it has been suggested that oak has benefited from the strong decline in economic uses of the forest such as pasturing, l…
Years of vegetation and settlement history from Egelsee (Menzingen, central Switzerland)
Past vegetation dynamics and human impact from the Lateglacial to the present are reconstructed by pollen analysis of a core 12 m long from the raised bog Egelsee, central Switzerland (770 m a.s.l.). The depth—age model of the core is based on 29 AMS 14 C dates. The oldest dated macrofossil has an age of 13 080 ± 105 radiocarbon yr BP (15 370 cal. yr BP); extrapolation leads to a basal age of the core of 16 200 cal. yr BP. The biostratigraphy sho…
Testing the influence of climate, human impact and fire on the Holocene population expansion of Fagus sylvatica in the southern Prealps (Italy)
This study addresses the timing and causes of the Holocene population expansion of Fagus sylvatica at two sites in the southern Prealps (Italy): Lago di Fimon and Lago Piccolo di Avigliana. At both sites pollen and microcharcoal have been analysed at high temporal resolution. The impact of humans and of fire on the forest dynamics is tested by means of time-series analysis and the influence of climatic change has been inferred from summer tempera…
Biotic response to rapid climatic changes during the Late Glacial
Organisms can respond to rapid climatic changes in three ways: 1) adaptation by evolution, affecting physiology and morphology), 2) migration and population dynamics including biogeographical changes) and 3) extinction local or global). Here, the focus is on examples of the second type. Organisms, whether algae, trees, or animals, find their ecological niches in a multi- dimensional space of gradients such as temperature winter, summer, means or …
Effects of climatic change and bog development on Holocene tufa formation in the Lorze Valley (central Switzerland)
A massive tufa complex in the lower Lorze Valley (550 m a.s.l., north-central Switzerland) formed between 9000 and 5000 cal. yr BP. In the plain 4 km southeast of the complex lies Neugrundmoor (830 m a.s.l.), a mire in the hydrologic recharge area of the springs responsible for the tufa formation. Here we address an earlier, untested hypothesis that the transition of Neugrundmoor from fen to raised bog caused the end of the tufa formation, by mea…
Annual pollen traps reveal the complexity of climatic control on pollen productivity in Europe and the Caucasus
Annual PAR (pollen accumulation rates; grains cm−2 year−1) were studied with modified Tauber traps situated in ten regions, in Poland (Roztocze), the Czech Republic (two regions in Krkonoše, two in Šumava), Switzerland (4 regions in the Alps), and Georgia (Lagodekhi). The time-series are 10–16 years long, all ending in 2007. We calculated correlations between pollen data and climate. Pollen data are PAR summarized per region (4–7 traps selected p…
A new Late-glacial and Holocene record of vegetation and fire history from Lago del Greppo, northern Apennines, Italy
Biotic responses to rapid warming at Termination 1a at Gerzensee (Central Europe) – Hypotheses about succession, albedo, soils, lake development, and ecological interactions
Palynological richness and evenness
The potential of stomata analysis in conifers to estimate presence of conifer trees
Gerhard Lang (21.10.1924–19.6.2016)
In Memoriam
Herbert E Wright Jr was one of the foremost Quaternary scientists of the last century. He made wide ranging contributions to our understanding of the late-Quaternary of North and South America, Europe, Asia and Africa. This was based largely on reconstructing palaeoenvironments from lake sediments and included the important implications for glacial, vegetational, fire and climatic history, geoarchaeology and conservation. Many of his inter-discip…
Geology and Paleoclimatology Research (21 obras) · Biology (18 obras) · Ecology (18 obras) · Geography (18 obras) · Pollen (17 obras) · Geology (16 obras) · Physical geography (15 obras) · Holocene (13 obras) · Paleontology (11 obras) · Macrofossil (10 obras)