Holocentric chromosomes-chromosomes that lack localized centromeres-occur in numerous unrelated clades of insects, flatworms, and angiosperms. Chromosome number changes in such organisms often result from fission and fusion events rather than polyploidy. In this study, I test the hypothesis that chromosome number evolves according to a uniform process in Carex section Ovales (Cyperaceae), the l...

We assessed the size and composition of the seed bank in 31 plots representing a range of habitats within an old-growth, temperate deciduous forest at Mont St. Hilaire, Québec, Canada. We identified 49 taxa in the seed bank, with an average of 40 species·m–2 and a median density of 1218 seeds·m–2. The most frequent seeds were species of Carex and Rubus, Diervilla lonicera, and Eupatorium rugosu...

The present article describes the heavy metal content (Ni, Pb, Cd) in top plant phytomass: blue marsh bog (Eleocharis palustris (L.) Roem. Schult.), furcular Anemonidium (Anemonidium dichotomum Holub), bayonet rush (Juncus filiformis L.), vetchling (Lathyrus carex acuta (Carex reed canary grass (Phalaroides arundinacea clump speedwell (Veronica longifolia silverweed cinquefoil (Potentilla anser...

1 A ®eld experiment was designed to investigate the relationship between environmental heterogeneity and species diversity in a group of sedges (Cyperaceae: Carex) growing in old-growth forest. 2 A measure of environmental quality, as perceived by the sedges, was obtained from the survival of clonal ramets of 11 species of Carex planted at 10-m intervals along each of three 1-km transect lines....

Previous work on holocentric chromosomes in the angiosperm genus Carex demonstrates that many of the traditional sections are marked by different ranges of chromosome number, suggesting phylogenetic autocorrelation. It has been hypothesized that shifting constraints on chromosome rearrangements may limit the potential for hybridization among lineages, promoting speciation. In this study, we eva...

Plants are a major factor influencing methane emissions from wetlands, along with environmental parameters such as water table, temperature, pH, nutrients and soil carbon substrate. We conducted a field experiment to study how different plant species influence methane emissions from a wetland in Switzerland. The top 0.5 m of soil at this site had been removed five years earlier, leaving a subst...