This Article Full Text (PDF) References Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Add to Saved Citations Download to citation manager Request Permissions Request Reprints Add to My Marked Citations Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Citing Articles via Scopus Google Scholar Articles by Mitchell, E. A.D. Articles by Gobat, J.-M. Search for Related Content GeoRef GeoRef Citation Social Bookmarking                         What's this?

The palaeoecological history of the Praz-Rodet bog (Swiss Jura) based on pollen, plant macrofossils and testate amoebae (Protozoa)

Botany Institute, University of Neuchadtel, Rue Emile Argand 11, CH-2007 Neuchatel, Switzerland

W. O. van der Knaap

J. F.N. van Leeuwen

Geobotanical Institute, University of Bern, Altenbergrain 21, CH-3013 Bern, Switzerland

A. Buttler

Laboratoire de Chrono-ecologie, UMR 6565 CNRS, UFR des Sciences et Techniques, 16 route de Gray, Universite de Franche-Comte, 25030 Besanfon, France; Swiss Federal Institute for Forest, Snow and Landscape Research (WSL/FNP), Antenne Romande c/o EPEL, 1015 Lausanne, Switzerland

B. G. Warner

Department of Geography and Wetlands Research Center, University of Waterloo, Ontario, Canada N2L 3G1

J.-M. Gobat

Botany Institute, University of Neuchadtel, Rue Emile Argand 11, CH-2007 Neuchatel, Switzerland

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 inferred development of the Praz-Rodet bog typifies a classic hydroseral tefrestrialization of a small basin. Two features are specific for this site. First, the bog was much wetter than today for a long period; according to our hypothesis, this only changed as a consequence of human activities. Second, two hiatuses are present at the coring location (Younger Dryas--early Preboreal, and 4700-2800 cal. yr BP), the former probably caused by low lake productivity due to cold temperatures and the latter by the erosional activity of the adjacent small river. The date of 2800 cal. yr BP for renewed peat accumulation may be related to climatic change (Subboreal-Subatlantic transition). Pollen indicators failed to show one hiatus: an apparently complete pollen sequence is therefore no guarantee of an uninterrupted sediment accumulation. Evidence of early minor human impact on the vegetation in the Joux Valley dates back to c. 6850 calendar years, congruous with the early Neolithic in the Jura Mountains. The history of Pinuis rotindata appears to be more complex than previously believed. Human activity is clearly responsible for the present abundance of this species, but the tree was naturally present on the bog long before the first evidence of important human disturbance of the site (1500 cal. yr BP). It is suggested that, in karst-dominated landscapes, dense forests growing on mineral soils around raised bogs may significantly reduce summer evapotranspiration by acting as windbreaks. Forest clearance results in increased evapotranspiration, causing a lowering of the water table on the bog and a modification of the vegetation cover. This hypothesis has implications for the management of similar small raised bogs in karst-dominated landscape.

Key Words: pollen • plant macrofossils • testate amoebae • Lateglacial • Holocene • peat bog • human impact • Pinus rotundata • Switzerland

The Holocene, Vol. 11, No. 1, 65-80 (2001)
DOI: 10.1191/095968301671777798


CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter    What's this?

This article has been cited by other articles:

				M. Lamentowicz, K. Tobolski, and E. A.D. Mitchell Palaeoecological evidence for anthropogenic acidification of a kettle-hole peatland in northern Poland The Holocene, December 1, 2007; 17(8): 1185 - 1196. [Abstract] [PDF]

				P. Sjogren The development of pasture woodland in the southwest Swiss Jura Mountains over 2000 years, based on three adjacent peat profiles The Holocene, February 1, 2006; 16(2): 210 - 223. [Abstract] [PDF]

				K. Schoning, K. Schoning, D. J. Charman, and S. Wastegoard Reconstructed water tables from two ombrotrophic mires in eastern central Sweden compared with instrumental meteorological data The Holocene, January 1, 2005; 15(1): 111 - 118. [Abstract] [PDF]

				F. M. Chambers, F. M. Chambers, and D. J. Charman Holocene environmental change: contributions from the peatland archive The Holocene, January 1, 2004; 14(1): 1 - 6. [Abstract] [PDF]

				F. Roos-Barraclough, F. Roos-Barraclough, W. O. van der Knaap, J. F.N. van Leeuwen, and W. Shotyk A Late-glacial and Holocene record of climatic change from a Swiss peat humification profile The Holocene, January 1, 2004; 14(1): 7 - 19. [Abstract] [PDF]

				W. O. van der Knaap, W. O. van der Knaap, and J. F.N. van Leeuwen Climate-pollen relationships AD 1901-1996 in two small mires near the forest limit in the northern and central Swiss Alps The Holocene, September 1, 2003; 13(6): 809 - 828. [Abstract] [PDF]