Uppermost Limit, Extent, and Fluctuations of the Timberline and Treeline Ecocline in the Swiss Central Alps during the past 11,500 Years
Pollen and macrofossils were analyzed at two sites above today's treeline (or tree limit) in the Swiss Central Alps (Gouillé Loéré, 2503 m a.s.l., and Lengi Egga, 2557 m a.s.l.) to test two contrasting hypotheses about the natural formation of timberline (the upper limit of closed forest) in th...
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Institute of Arctic and Alpine Research, University of Colorado at Boulder
2003
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Online Access: | https://boris.unibe.ch/83991/1/AAAR_35_158.pdf https://boris.unibe.ch/83991/ http://www.jstor.org/stable/1552367 |
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ftunivbern:oai:boris.unibe.ch:83991 2023-08-20T04:02:37+02:00 Uppermost Limit, Extent, and Fluctuations of the Timberline and Treeline Ecocline in the Swiss Central Alps during the past 11,500 Years Tinner, Willy Theurillat, Jean-Paul 2003-05 application/pdf https://boris.unibe.ch/83991/1/AAAR_35_158.pdf https://boris.unibe.ch/83991/ http://www.jstor.org/stable/1552367 eng eng Institute of Arctic and Alpine Research, University of Colorado at Boulder https://boris.unibe.ch/83991/ info:eu-repo/semantics/restrictedAccess Tinner, Willy; Theurillat, Jean-Paul (2003). Uppermost Limit, Extent, and Fluctuations of the Timberline and Treeline Ecocline in the Swiss Central Alps during the past 11,500 Years. Arctic, Antarctic, and Alpine Research, 35(2), pp. 158-169. Institute of Arctic and Alpine Research, University of Colorado at Boulder 580 Plants (Botany) info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion PeerReviewed 2003 ftunivbern 2023-07-31T21:27:00Z Pollen and macrofossils were analyzed at two sites above today's treeline (or tree limit) in the Swiss Central Alps (Gouillé Loéré, 2503 m a.s.l., and Lengi Egga, 2557 m a.s.l.) to test two contrasting hypotheses about the natural formation of timberline (the upper limit of closed forest) in the Alps. Our results revealed that Pinus cembra--Larix decidua forests near timberline were rather closed between 9000 and 2500 B.C. (9600-4000 14 C yr BP), when timberline fluctuations occurred within a belt 100-150 m above today's tree limit. The treeline ecocline above timberline was characterized by the mixed occurrence of tree, shrub, dwarf-shrub, and herbaceous species, but it did not encompass more than 100-150 altitudinal meters. The uppermost limit reached by timberline and treeline during the Holocene was ca. 2420 and 2530 m, respectively, i.e., about 120 to 180 m higher than today. Between 3500 and 2500 B.C. (4700-4000 14 C yr BP) timberline progressively sank by about 300 m, while treeline was lowered only ca. 100 m. This change led to an enlargement of the treeline-ecocline belt (by ca. 300 m) after 2500 B.C. (4000 14 C yr BP). Above the treeline ecocline, natural meadows dominated by dwarf shrubs (e.g., Salix herbacea) and herbaceous species (e.g., Helianthemum, Taraxacum, Potentialla, Leontodon t., Cerastium alpinum t., Cirsium spinosissimum, Silene exscapa t., and Saxifraga stellaris) have been present since at least 11,000 cal yr ago. In these meadows tree and tall shrub species (>0.5 m) never played a major role. These results support the conventional hypothesis of a narrow ecocline with rather sharp upper timberline and treeline boundaries and imply that today's treeless alpine communities in the Alps are close to a natural stage. Pollen (percentages and influx), stomata, and charcoal data may be useful for determining whether or not a site was treeless. Nevertheless, a reliable and detailed record of past local vegetation near and above timberline is best achieved through the inclusion of macrofossil ... Article in Journal/Newspaper Antarctic and Alpine Research Arctic Arctic and Alpine Research Salix herbacea BORIS (Bern Open Repository and Information System, University of Bern) Egga ENVELOPE(14.802,14.802,68.830,68.830) |
institution |
Open Polar |
collection |
BORIS (Bern Open Repository and Information System, University of Bern) |
op_collection_id |
ftunivbern |
language |
English |
topic |
580 Plants (Botany) |
spellingShingle |
580 Plants (Botany) Tinner, Willy Theurillat, Jean-Paul Uppermost Limit, Extent, and Fluctuations of the Timberline and Treeline Ecocline in the Swiss Central Alps during the past 11,500 Years |
topic_facet |
580 Plants (Botany) |
description |
Pollen and macrofossils were analyzed at two sites above today's treeline (or tree limit) in the Swiss Central Alps (Gouillé Loéré, 2503 m a.s.l., and Lengi Egga, 2557 m a.s.l.) to test two contrasting hypotheses about the natural formation of timberline (the upper limit of closed forest) in the Alps. Our results revealed that Pinus cembra--Larix decidua forests near timberline were rather closed between 9000 and 2500 B.C. (9600-4000 14 C yr BP), when timberline fluctuations occurred within a belt 100-150 m above today's tree limit. The treeline ecocline above timberline was characterized by the mixed occurrence of tree, shrub, dwarf-shrub, and herbaceous species, but it did not encompass more than 100-150 altitudinal meters. The uppermost limit reached by timberline and treeline during the Holocene was ca. 2420 and 2530 m, respectively, i.e., about 120 to 180 m higher than today. Between 3500 and 2500 B.C. (4700-4000 14 C yr BP) timberline progressively sank by about 300 m, while treeline was lowered only ca. 100 m. This change led to an enlargement of the treeline-ecocline belt (by ca. 300 m) after 2500 B.C. (4000 14 C yr BP). Above the treeline ecocline, natural meadows dominated by dwarf shrubs (e.g., Salix herbacea) and herbaceous species (e.g., Helianthemum, Taraxacum, Potentialla, Leontodon t., Cerastium alpinum t., Cirsium spinosissimum, Silene exscapa t., and Saxifraga stellaris) have been present since at least 11,000 cal yr ago. In these meadows tree and tall shrub species (>0.5 m) never played a major role. These results support the conventional hypothesis of a narrow ecocline with rather sharp upper timberline and treeline boundaries and imply that today's treeless alpine communities in the Alps are close to a natural stage. Pollen (percentages and influx), stomata, and charcoal data may be useful for determining whether or not a site was treeless. Nevertheless, a reliable and detailed record of past local vegetation near and above timberline is best achieved through the inclusion of macrofossil ... |
format |
Article in Journal/Newspaper |
author |
Tinner, Willy Theurillat, Jean-Paul |
author_facet |
Tinner, Willy Theurillat, Jean-Paul |
author_sort |
Tinner, Willy |
title |
Uppermost Limit, Extent, and Fluctuations of the Timberline and Treeline Ecocline in the Swiss Central Alps during the past 11,500 Years |
title_short |
Uppermost Limit, Extent, and Fluctuations of the Timberline and Treeline Ecocline in the Swiss Central Alps during the past 11,500 Years |
title_full |
Uppermost Limit, Extent, and Fluctuations of the Timberline and Treeline Ecocline in the Swiss Central Alps during the past 11,500 Years |
title_fullStr |
Uppermost Limit, Extent, and Fluctuations of the Timberline and Treeline Ecocline in the Swiss Central Alps during the past 11,500 Years |
title_full_unstemmed |
Uppermost Limit, Extent, and Fluctuations of the Timberline and Treeline Ecocline in the Swiss Central Alps during the past 11,500 Years |
title_sort |
uppermost limit, extent, and fluctuations of the timberline and treeline ecocline in the swiss central alps during the past 11,500 years |
publisher |
Institute of Arctic and Alpine Research, University of Colorado at Boulder |
publishDate |
2003 |
url |
https://boris.unibe.ch/83991/1/AAAR_35_158.pdf https://boris.unibe.ch/83991/ http://www.jstor.org/stable/1552367 |
long_lat |
ENVELOPE(14.802,14.802,68.830,68.830) |
geographic |
Egga |
geographic_facet |
Egga |
genre |
Antarctic and Alpine Research Arctic Arctic and Alpine Research Salix herbacea |
genre_facet |
Antarctic and Alpine Research Arctic Arctic and Alpine Research Salix herbacea |
op_source |
Tinner, Willy; Theurillat, Jean-Paul (2003). Uppermost Limit, Extent, and Fluctuations of the Timberline and Treeline Ecocline in the Swiss Central Alps during the past 11,500 Years. Arctic, Antarctic, and Alpine Research, 35(2), pp. 158-169. Institute of Arctic and Alpine Research, University of Colorado at Boulder |
op_relation |
https://boris.unibe.ch/83991/ |
op_rights |
info:eu-repo/semantics/restrictedAccess |
_version_ |
1774713160317534208 |