Edward A D Mitchell
Biographic Data
| ID | 1949512 |
|---|---|
| NAME | Edward A D Mitchell |
| GIVEN NAMES | Edward A D |
| FAMILY NAME | Mitchell |
| SIGNATURE | MITCHELL E A D |
| AFFILIATIONS | University of Neuchâtel |
| ORCID | 0000-0003-0358-506X |
| VERIFIED | Yes |
| TOTAL WORKS | 10 |
| TOTAL CITATIONS | 14 |
| WORKS AS AUTHOR | 10 |
| WORKS AS EDITOR | 0 |
| FIRST PUBLICATION YEAR | 2001 |
| LATEST PUBLICATION YEAR | 2022 |
| H-INDEX | 2 |
Late-Glacial and Holocene Lake-Level Fluctuations on the Kenai Lowland, Reconstructed from Satellite-Fen Peat Deposits and Ice-Shoved Ramparts, Kenai Peninsula, Alaska
Recent decades of warmer climate have brought drying wetlands and falling lake levels to southern Alaska. These recent changes can be placed into a longer-term context of postglacial lake-level fluctuations that include low stands that were as much as 7 m lower than present at eight lakes on the Kenai Lowland. Closed-basin lakes on the Kenai Lowland are typically ringed with old shorelines, usually as wave-cut scarps, cut several meters above mod…
From Climatic to Anthropogenic Drivers
A 4 m core was extracted from the center of a peatland located in the Drugeon valley (France). Thirteen radiocarbon dates were used to build a robust age model. Testate amoebae were used for reconstructing mire surface wetness. High-resolution pollen analysis of the sequence reconstructed 9 millennia of development of the peatland and its surrounding vegetation. During the early/middle Holocene (9500 to 5800 cal BP), warm conditions led to high e…
Functional traits as a new approach for interpreting testate amoeba palaeo-records in peatlands and assessing the causes and consequences of past changes in species composition
Subfossil remains of various groups of organisms preserved in peat and sediment archives are commonly used to infer past environmental changes using transfer functions based on species composition. However, the changes in community structure can also be explored using the functional trait approach. Investigation of functional traits in palaeoecological records can inform about the mechanisms through which abiotic variables such as temperature or …
The performance of single- and multi-proxy transfer functions (testate amoebae, bryophytes, vascular plants) for reconstructing mire surface wetness and pH
Peatlands are widely exploited archives of paleoenvironmental change. We developed and compared multiple transfer functions to infer peatland depth to the water table (DWT) and pH based on testate amoeba (percentages, or presence/absence), bryophyte presence/absence, and vascular plant presence/absence data from sub-alpine peatlands in the SE Swiss Alps in order to 1) compare the performance of single-proxy vs. multi-proxy models and 2) assess th…
Can pollution bias peatland paleoclimate reconstruction?
Peatland testate amoebae are widely used to reconstruct paleohydrological/climatic changes, but many species are also known to respond to pollutants. Peatlands around the world have been exposed to anthropogenic and intermittent natural pollution through the late Holocene. This raises the question: can pollution lead to changes in the testate amoeba paleoecological record that could be erroneously interpreted as a climatic change? To address this…
Testing peatland testate amoeba transfer functions
Transfer functions are widely used in palaeoecology to infer past environmental conditions from fossil remains of many groups of organisms. In contrast to traditional training-set design with one observation per site, some training-sets, including those for peatland testate amoeba-hydrology transfer functions, have a clustered structure with many observations from each site. Here we show that this clustered design causes standard performance stat…
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…
Palaeoecological evidence for anthropogenic acidification of a kettle-hole peatland in northern Poland
The Holocene developmental history of a small kettle-hole peatland in northern Poland was studied using radiocarbon dating and analyses of pollen, plant macrofossils and testate amoebae with the aim of sorting out the influences of climate change, autogenic succession and human impact. The mire followed the classical succession from lake to a Sphagnum-dominated peatland, but peat accumulation only started about 3000 cal. BP. A rapid shift to wett…
Ecology of testate amoebae (Protista) in south-central Alaska peatlands
Testate amoebae are valuable indicators of peatland hydrology and have been used in many palaeoclimatic studies in peatlands. Because the species' ecological optima may vary around the globe, the development of transfer function models is an essential prerequisite for regional palaeoclimatic studies using testate amoebae. We investigated testate amoebae ecology in nine peatlands covering a 250-km north-south transect in south-central Alaska. Redu…
The palaeoecological history of the Praz-Rodet bog (Swiss Jura) based on pollen, plant macrofossils and testate amoebae (Protozoa)
Stratigraphy, radiocarbon dating and analyses of pollen, plant macrofossils and testate amoebae were used to reconstruct the development and ecology of a small raised bog in a karst-dominated landscape in the Swiss Jura Mountains. Special focus was on past vegetation and on the history of Pinus rotundata in relation to anthropogenic and climatic influences. Testate amoebae were used to reconstruc-t past local soil pH and water-table depth. The in…
The palaeoecological history of the Praz-Rodet bog (Swiss Jura) based on pollen, plant macrofossils and testate amoebae (Protozoa)
Stratigraphy, radiocarbon dating and analyses of pollen, plant macrofossils and testate amoebae were used to reconstruct the development and ecology of a small raised bog in a karst-dominated landscape in the Swiss Jura Mountains. Special focus was on past vegetation and on the history of Pinus rotundata in relation to anthropogenic and climatic influences. Testate amoebae were used to reconstruc-t past local soil pH and water-table depth. The in…
Ecology of testate amoebae (Protista) in south-central Alaska peatlands
Testate amoebae are valuable indicators of peatland hydrology and have been used in many palaeoclimatic studies in peatlands. Because the species' ecological optima may vary around the globe, the development of transfer function models is an essential prerequisite for regional palaeoclimatic studies using testate amoebae. We investigated testate amoebae ecology in nine peatlands covering a 250-km north-south transect in south-central Alaska. Redu…
Palaeoecological evidence for anthropogenic acidification of a kettle-hole peatland in northern Poland
The Holocene developmental history of a small kettle-hole peatland in northern Poland was studied using radiocarbon dating and analyses of pollen, plant macrofossils and testate amoebae with the aim of sorting out the influences of climate change, autogenic succession and human impact. The mire followed the classical succession from lake to a Sphagnum-dominated peatland, but peat accumulation only started about 3000 cal. BP. A rapid shift to wett…
Functional traits as a new approach for interpreting testate amoeba palaeo-records in peatlands and assessing the causes and consequences of past changes in species composition
Subfossil remains of various groups of organisms preserved in peat and sediment archives are commonly used to infer past environmental changes using transfer functions based on species composition. However, the changes in community structure can also be explored using the functional trait approach. Investigation of functional traits in palaeoecological records can inform about the mechanisms through which abiotic variables such as temperature or …
Testing peatland testate amoeba transfer functions
Transfer functions are widely used in palaeoecology to infer past environmental conditions from fossil remains of many groups of organisms. In contrast to traditional training-set design with one observation per site, some training-sets, including those for peatland testate amoeba-hydrology transfer functions, have a clustered structure with many observations from each site. Here we show that this clustered design causes standard performance stat…
The palaeoecological history of the Praz-Rodet bog (Swiss Jura) based on pollen, plant macrofossils and testate amoebae (Protozoa)
Stratigraphy, radiocarbon dating and analyses of pollen, plant macrofossils and testate amoebae were used to reconstruct the development and ecology of a small raised bog in a karst-dominated landscape in the Swiss Jura Mountains. Special focus was on past vegetation and on the history of Pinus rotundata in relation to anthropogenic and climatic influences. Testate amoebae were used to reconstruc-t past local soil pH and water-table depth. The in…
Ecology of testate amoebae (Protista) in south-central Alaska peatlands
Testate amoebae are valuable indicators of peatland hydrology and have been used in many palaeoclimatic studies in peatlands. Because the species' ecological optima may vary around the globe, the development of transfer function models is an essential prerequisite for regional palaeoclimatic studies using testate amoebae. We investigated testate amoebae ecology in nine peatlands covering a 250-km north-south transect in south-central Alaska. Redu…
Palaeoecological evidence for anthropogenic acidification of a kettle-hole peatland in northern Poland
The Holocene developmental history of a small kettle-hole peatland in northern Poland was studied using radiocarbon dating and analyses of pollen, plant macrofossils and testate amoebae with the aim of sorting out the influences of climate change, autogenic succession and human impact. The mire followed the classical succession from lake to a Sphagnum-dominated peatland, but peat accumulation only started about 3000 cal. BP. A rapid shift to wett…
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…
Testing peatland testate amoeba transfer functions
Transfer functions are widely used in palaeoecology to infer past environmental conditions from fossil remains of many groups of organisms. In contrast to traditional training-set design with one observation per site, some training-sets, including those for peatland testate amoeba-hydrology transfer functions, have a clustered structure with many observations from each site. Here we show that this clustered design causes standard performance stat…
Can pollution bias peatland paleoclimate reconstruction?
Peatland testate amoebae are widely used to reconstruct paleohydrological/climatic changes, but many species are also known to respond to pollutants. Peatlands around the world have been exposed to anthropogenic and intermittent natural pollution through the late Holocene. This raises the question: can pollution lead to changes in the testate amoeba paleoecological record that could be erroneously interpreted as a climatic change? To address this…
The performance of single- and multi-proxy transfer functions (testate amoebae, bryophytes, vascular plants) for reconstructing mire surface wetness and pH
Peatlands are widely exploited archives of paleoenvironmental change. We developed and compared multiple transfer functions to infer peatland depth to the water table (DWT) and pH based on testate amoeba (percentages, or presence/absence), bryophyte presence/absence, and vascular plant presence/absence data from sub-alpine peatlands in the SE Swiss Alps in order to 1) compare the performance of single-proxy vs. multi-proxy models and 2) assess th…
Functional traits as a new approach for interpreting testate amoeba palaeo-records in peatlands and assessing the causes and consequences of past changes in species composition
Subfossil remains of various groups of organisms preserved in peat and sediment archives are commonly used to infer past environmental changes using transfer functions based on species composition. However, the changes in community structure can also be explored using the functional trait approach. Investigation of functional traits in palaeoecological records can inform about the mechanisms through which abiotic variables such as temperature or …
From Climatic to Anthropogenic Drivers
A 4 m core was extracted from the center of a peatland located in the Drugeon valley (France). Thirteen radiocarbon dates were used to build a robust age model. Testate amoebae were used for reconstructing mire surface wetness. High-resolution pollen analysis of the sequence reconstructed 9 millennia of development of the peatland and its surrounding vegetation. During the early/middle Holocene (9500 to 5800 cal BP), warm conditions led to high e…
Late-Glacial and Holocene Lake-Level Fluctuations on the Kenai Lowland, Reconstructed from Satellite-Fen Peat Deposits and Ice-Shoved Ramparts, Kenai Peninsula, Alaska
Recent decades of warmer climate have brought drying wetlands and falling lake levels to southern Alaska. These recent changes can be placed into a longer-term context of postglacial lake-level fluctuations that include low stands that were as much as 7 m lower than present at eight lakes on the Kenai Lowland. Closed-basin lakes on the Kenai Lowland are typically ringed with old shorelines, usually as wave-cut scarps, cut several meters above mod…
Geology and Paleoclimatology Research (10 works) · Peat (10 works) · Biology (9 works) · Testate amoebae (8 works) · Ecology (7 works) · Geography (7 works) · Holocene (7 works) · Peatlands and Wetlands Ecology (7 works) · Physical geography (7 works) · Geology (6 works)