HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Supplementary Data Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Gonzales, E. Articles by Smouse, P. E. Search for Related Content PubMed Articles by Gonzales, E. Articles by Smouse, P. E. Agricola Articles by Gonzales, E. Articles by Smouse, P. E.

Comparison of clonal diversity in mountain and Piedmont populations of Trillium cuneatum (Melanthiaceae-Trilliaceae), a forest understory species¹

² Biology Department, Appalachian State University, Boone, North Carolina 28607 USA ³ Plant Biology Department, University of Georgia, Athens, Georgia 30602 USA ⁴ Department of Ecology, Evolution & Natural Resources, Rutgers University, 14 College Farm Road, New Brunswick, New Jersey 08901-8551 USA

ABSTRACT

The balance between clonal and sexual reproduction can vary widely among plant populations, and the extent of clonality may be influenced by the combined effects of historical land use and variation in environmental conditions. We investigated patterns of clonal spread in five Trillium cuneatum populations, two in the Appalachian Mountains characterized by mesic, cooler conditions, and three at lower elevations experiencing warmer, drier conditions and greater disturbance. Using a new measure of the genet effective number and innovative orthogonal contrast methods, we quantified genet structure, contrasting clonal growth in the mountains with that in the Piedmont. Asexual propagation was more common in the Piedmont, where 25% of the sampled ramets were clonally derived, but was much less frequent in the mountains (7% clonal replicates). Hierarchical partitioning of variation in genet diversity showed that the majority (75.8%) of the variation resulted from more vegetative replication in the Piedmont. Most of the remaining variation (21.6%) was attributable to differences between urban and rural Piedmont populations, and a small, statistically nonsignificant fraction of the variation (2.6%) was due to interpopulation differences within the mountains. Higher frequency of cloning may enhance both genetic and demographic population viability in fragmented Piedmont habitats.

Key Words: clonal structure • genet diversity • heterogeneous environments • orthogonal contrasts • Southeastern USA • vegetative reproduction • Trillium

Received for publication 22 May 2007. Accepted for publication 14 July 2008.