Rhizocarpon Ram. em. Th. Fr. Subgen. Rhizocarpon in Europe

Poelt, Josef; Cernohorsky, Z.; Schaefer, Judith

doi:10.2307/1551261

Cited by 51 publications

(51 citation statements)

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“…All lichens had sharp margins with clearly defined hypothalli. All thalli were identified in the field, using the criteria of Poelt (1988), as Rhizocarpon section Rhizocarpon (formerly the Geographicum group of Runemark (1956)). Although chemical identification to species level was not undertaken in Iceland, all 41 thalli were examined using a x8 handlens against the broadly circumscribed criteria of Purvis et al (1992); most could be identified as…”

Section: Non-competing Approximately Circular Rhizocarpon Section Rmentioning

confidence: 99%

Growth rates of Rhizocarpon geographicum lichens: a review with new data from Iceland

Bradwell

Armstrong

2006

J Quaternary Science

100

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This article reviews evidence from previous growth-rate studies on lichens of the yellowgreen species of Subgenus Rhizocarpon -the family most commonly used in lichenometric growth-rate curve is parabolic and is best described by a third-order polynomial function.The striking similarity between these findings in Iceland and those of Armstrong (1983) in Wales implies that the shape of the growth-rate curve may be characteristic of Rhizocarpon geographicum lichens. The difference between the absolute growth rate in southern Iceland and Wales (c. 66% faster) is probably a function of climate and micro-environment between the two sites. These findings have implications for previous lichenometric-dating studies;namely, that those studies which assume constant lichen growth rates over many decades are probably unreliable.

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Section: Non-competing Approximately Circular Rhizocarpon Section Rmentioning

confidence: 99%

Growth rates of Rhizocarpon geographicum lichens: a review with new data from Iceland

Bradwell

Armstrong

2006

J Quaternary Science

100

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“…Innes, 1985a;Worsley, 1990;Matthews, 1994) with the aim of detecting synchronous moraine formation and hence possible Little Ice Age climatic fluctuations. The longest axes of specimens of the yellow-green crustose lichens of Rhizocarpon subgenus (Innes, 1985b;Poelt, 1988) were measured to the nearest millimetre from 25-m lengths of moraine proximal to the crest. Formerly known as Rhizocarpon geographicum agg., the lichens measured include specimens of both section Rhizocarpon and section Alpicola.…”

Section: Lichenometrymentioning

confidence: 99%

Glacier variations in Breheimen, southern Norway: dating Little Ice Age moraine sequences at seven low‐altitude glaciers

Winkler

Matthews

Shakesby

et al. 2003

J Quaternary Science

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2003. Glacier variations in Breheimen, southern Norway: dating Little Ice Age moraine sequences at seven low-altitude glaciers.ABSTRACT: Moraine sequences in front of seven relatively low-altitude glaciers in the Breheimen region of central southern Norway are described and dated using a 'multi-proxy' approach to moraine stratigraphy. Lichenometric dating, based on the Rhizocarpon subgenus, is used to construct a composite moraine chronology, which indicates eight phases of synchronous moraine formation: AD . Although the existence of a few cases of older moraines, possibly dating from earlier in the eighteenth or late in the seventeenth centuries cannot be ruled out by lichenometry, Schmidt hammer R-values from boulders on outermost moraine ridges suggest an absence of Holocene moraines older than the Little Ice Age. Twenty-three radiocarbon dates from buried soils and peat associated with outermost moraines at three glaciers-Tverreggibreen, Storegrovbreen and Greinbreen-also indicate that the 'Little Ice Age' glacier maximum was the Neoglacial maximum at most if not all glaciers. Several maximum age estimates for the Little Ice Age glacier maximum range between the fifteenth and seventeenth centuries, with the youngest from a buried soil being AD 1693. A pre-Little Ice Age maximum cannot be ruled out at Greinbreen, however, where the age of buried peat suggests the outermost moraine dates from AD 981-1399 (at variance with the lichenometric evidence). Glaciofluvial stratigraphy at Tverreggibreen provides evidence for minor glacier advances about AD 655-963 and AD 1277-1396, respectively.

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“…The Kaunertal valley was developed mainly from paragneisses and orthogneisses (Tollmann 1977), which poses challenges for SHRT due to the diversity of coarse grained rocks, because large crystals of different minerals vary in strength, resulting in a differential rebound of the impact plunger (R-values). On the other hand, basic or light acidic pH allows the growth of Rhizocarpon lichens (Poelt 1988) which are best suited for lichenometry due to their slow growth rate (Bradwell & Armstrong 2006).…”

Section: Study Sitementioning

confidence: 99%

Lichenometry and Schmidt hammer tests in the Kaunertal glacier foreland (Ötztal Alps) during the AMADEE-15 Mars Mission Simulation

Czempiński

Dąbski

2017

Miscellanea Geographica

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The aim of this article is to show the results of the lichenometrical and Schmidt hammer measurements performed in 2015 during the AMADEE-15 Mars Mission Simulation in the Ötztal Alps in order to test the capabilities of analogue astronauts and collect information on the geomorphic history of the study area since the Little Ice Age (LIA). The results obtained differ significantly from our expectations, which we attribute to differences in the field experience of participants and the astronauts' technical limitations in terms of mobility. However, the experiments proved that these methods are within the range of the astronauts' capabilities. Environmental factors, such as i) varied petrography, ii) varied number of thalli in test polygons, and iii) differences in topoclimatic conditions between the LIA moraine and the glacier front, further inhibited simple interpretation. The LIA maximum of the Kaunertal glacier occurred in AD 1850, and relative stabilization of the frontal part of the rock glacier occurred in AD 1711.

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Rhizocarpon Ram. em. Th. Fr. Subgen. Rhizocarpon in Europe

Cited by 51 publications

References 0 publications

Growth rates of Rhizocarpon geographicum lichens: a review with new data from Iceland

Growth rates of Rhizocarpon geographicum lichens: a review with new data from Iceland

Glacier variations in Breheimen, southern Norway: dating Little Ice Age moraine sequences at seven low‐altitude glaciers

Lichenometry and Schmidt hammer tests in the Kaunertal glacier foreland (Ötztal Alps) during the AMADEE-15 Mars Mission Simulation

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