Equal seed set and germination rate over distance and indication of self incompatibility in artificial crosses of Filipendula ulmaria

Paternity analysis in Filipendula ulmaria indicates high level of gene flow between populations, using AFLP

High gene flow and differences in pollination pattern in a paternity analysis of a small riparian population of Filipendula ulmaria

Differences in spatial genetic structure of riparian Filipendula ulmaria between an within river catchments in northern Sweden

Spatial genetic structure of a common riparian plant species, Meadowsweet (Filipendula ulmaria) in northern Sweden

Fragmentation and flow regulation of rivers by large dams are known to obstruct the longitudinal dispersal of waterbome plant propagules between impoundments, and to affect plant community composition. However, even several decades after a dam has been built, impoundments may still have a relatively species-rich riparian flora. We hypothesized that free-flowing tributaries act as the major gene pools for such impoundments, thus alleviating the fragmenting effect large dams have on the main channel. The importance of tributaries as seed sources was tested by releasing wooden seed mimics in three different-sized (0.22-6.93 m(3) s(-1)) tributaries of an impoundment in the Ume River in Northern Sweden. In each tributary seed mimics were released, during the spring flood peak, from three points approximately 1, 2 and 3 km upstream the outlet in the impoundment. The importance of a tributary as a seed source increased with tributary size. Of the 9000 released seed mimics 1.5% reached the impoundment; 1.2% of the 9000 originated from the largest tributary and 0.3% from the middle-sized one. The smallest tributary retained all its mimics. Copyright (C) 2007 John Wiley & Sons, Ltd.

Human impacts to aquatic ecosystems often involve changes in hydrologic connectivity and flow regime.Drawing upon examples in the literature and from our experience, we developed conceptual models and used simple bivariate plots to visualize human impacts and restoration efforts in terms of connectivity and flow dynamics.Human-induced changes in longitudinal, lateral, and vertical connectivity are often accompanied by changes in flow dynamics, but in our experience restoration efforts to date have more often restored connectivity than flow dynamics.Restoration actions have included removing dams to restore fish passage, reconnecting flow through artificially cut-off side channels, setting back or breaching levees, and removing fine sediment deposits that block vertical exchange with the bed, thereby partially restoring hydrologic connectivity, i.e., longitudinal, lateral, or vertical.Restorations have less commonly affected flow dynamics, presumably because of the social and economic importance of water diversions or flood control.Thus, as illustrated in these bivariate plots, the trajectories of ecological restoration are rarely parallel with degradation trajectories because restoration is politically and economically easier along some axes more than others.

previous study has shown that plant communities differ floristically between impoundments but remain similar within impoundments in a regulated river. The same pattern did not occur among plant species in a free-flowing river which instead showed a continuous change in species composition from the headwaters to the coast. This strongly suggests that the dispersal of plants is obstructed when dams are built on rivers. The present project will specifically study whether dams also affect the genetic diversity among and between populations of plant species. Filipendula ulmaria will be used as a first test species. A second question is whether tributaries have any impact on the distribution of genetic diversity of plant species within impoundments. A third question deals with the impact of seed and pollen dispersal on the genetic diversity among and between plant species populations. The project combines field sampling, field experiments and laboratory methods such as isoenzymes, microsatellites and other DNA-methods.

The 18S rRNA gene sequences from the bitunicate ascomycetes Ceramothyrium linnaeae (Chaetothyriaceae) and Coccodinium bartschii (Coccodiniaceae) were determined and aligned with the corresponding sequences from 33 other ascomycetes and one basidiomycete, Boletus satanas. Phylogenetic analyses of these sequences supported previous reports that the Herpotrichiellaceae (Capronia, black yeasts, etc.) are distant from Dothideales and Pleosporales. A new sequence of Ceramothyrium linnaeae, representing the family Chaetothyriaceae, is monophyletic with representatives of the Herpotrichiellaceae, suggesting that both families can be accommodated in the order Chaetothyriales. The concept of Chaetothyriales can not be based on the presence of periphysoids, since Coccodinium bartschii, which also has periphysoids, clustered with members of the Dothideaceae. The Chaetothyriales are not closely related to other bitunicates, but are the sister group of either Eurotiales or Lecanorales/Peltigerales.