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 Google Scholar Articles by Valsecchi, V. Articles by Ammann, B. Social Bookmarking                   What's this?

Testing the influence of climate, human impact and fire on the Holocene population expansion of Fagus sylvatica in the southern Prealps (Italy)

Palaeoecology, Laboratory of Palaeobotany & Palynology, Utrecht University, Budapestlaan 4, 3584 CD Utrecht, The Netherlands, v.g.valsecchi{at}uu.nl, Section of Paleoecology, Institute of Plant Sciences, University of Bern, Altenbergrain 21, CH-3013 Bern, Switzerland

Walter Finsinger

Palaeoecology, Laboratory of Palaeobotany & Palynology, Utrecht University, Budapestlaan 4, 3584 CD Utrecht, The Netherlands, Section of Paleoecology, Institute of Plant Sciences, University of Bern, Altenbergrain 21, CH-3013 Bern, Switzerland

Willy Tinner

Section of Paleoecology, Institute of Plant Sciences, University of Bern, Altenbergrain 21, CH-3013 Bern, Switzerland, Paleoecology and Vegetation Dynamics, Institute of Terrestrial Ecosystems, ETH Zurich, Universitätstrasse 22, CH-8092 Zurich, Switzerland

Brigitta Ammann

Section of Paleoecology, Institute of Plant Sciences, University of Bern, Altenbergrain 21, CH-3013 Bern, Switzerland

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 temperature and precipitation reconstructions in the Alps. The time intervals during which the population expansion of F. sylvatica occurred (ie, phases during which population doubling times were shortest) is determined by fitting linear regressions through the ln-transformed Fagus pollen-accumulation rate (ln(PAR)). At Lago di Fimon, the population expansion of F. sylvatica occurred at 7300–6400 cal. yr BP (FIM I). After a marked decline the population re-expanded at 5500–4700 cal. yr BP (FIM II). At Lago Piccolo di Avigliana F. sylvatica expanded c. 5300–4600 cal. yr BP (AVP I). Time-series analyses show that Fagus expanded after forest fires decreased during FIM I, and human impact likely contributed to the F. sylvatica population expansions at the two sites during FIM II and AVP I. The comparison with independent climatic records suggests that favourable climatic conditions (eg, cool and wet) were a determining factor. Our study suggests that the expansion of F. sylvatica populations has been triggered by more than one single factor alone.

Key Words: Fagus sylvatica • pollen • microcharcoal • climate • vegetation history • human impact • fire • plant populations • Holocene • Italy.

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