Many paradoxes exist about postglacial tree migration and they dont solve for many European trees. One example is wetland trees subgenus Alnus, which spread across Europe during the last glacial very quickly according to fossil records. The aim of this thesis is detection their migration potential, with the help of empirical evaluation of interpolated pollen data (interpolation method IDW) and a simulation model based on environmental characteristics of the species. The results of interpolated maps are similar to the rate previously estimated speed and the results of simulation model achieve these speeds only by A. incana but with specific extreme environmental conditions. The mason of this may be adapting its seeds to anemochorii because the simulation model confirmed their good potential to spread by the wind. Results of model for A. glutinosa don´t confirm the ability to rapidly spread by the wind and the observed rate must have another explanation. Maybe rivers can explain the empirical spread rate. This suggests visualization of migration lines and river networks. The model has also been disclosure of environmental properties that are related to migration potential. Within the parameterization of the model is demonstrated, that R0 of A. glutinosa is significantly better than A. incana. But main parameters of anemochory model are terminal velocity and generation time, which is shorter by the A. incana, and therefore is probably able to spread faster than A. glutinosa.

Coleanthus subtilis ist eine durch die FFH-Richtlinie geschützte, weltweit sehr seltene Art, welche periodisch trockenfallende Standorte in Flussauen (Primärhabitate) bzw. durch den Menschen geschaffene Staugewässer (Sekundärhabitate) besiedelt. Die Erarbeitung der aktuellen Verbreitungsbilder der Art in Sachsen und ihrer Besiedlungshistorie waren Ausgangspunkt für die Analysen zur Ökologie dieser Art. Anhand von Analysen zu den Ausbreitungsmechanismen, Standortansprüchen und Reaktionsmöglichkeiten von C. subtilis wurden grundlegende Beiträge zum besseren Verständnis der Strategien dieser Art erbracht. Die Arbeit gibt Hinweise für eine artenschutzgerechte Bewirtschaftung der Staugewässer insbesondere für die Regulierung von Zeitpunkt, Dauer, Intensität und Häufigkeit von Wasserstandsabsenkungen sowie hinsichtlich einzelner Praktiken im Zusammenhang mit einer fischereilichen Nutzung. Weiterhin zeigt die Arbeit auf, wie C. subtilis auf bestimmte, von den durchschnittlichen Wasserstandsschwankungen abweichende, Bedingungen reagieren kann. Damit sind nun wichtige Grundlagen zum nachhaltigen Schutz und zur Förderung von C. subtilis, insbesondere in Sekundärhabitaten, vorhanden. / Coleanthus subtilis is a globally rare species protected by the European Union Habitats Directive. This grass establishes on periodically drying sites in river floodplains (primary habitats) but also in man made ponds and reservoirs (secondary habitats). The identification of the present distribution patterns as well as the reconstruction of the colonisation history of C. subtilis in Saxony were the basis for analyses about the ecology of this species. By analysing dispersal mechanisms, habitat demands and response traits of C. subtilis fundamental contributions to a better understanding of the strategies of this species are given. The thesis provides information about optimum time, duration, intensity and frequency of water level reductions and about the consequences of different management practices particularly with respect to fishery in ponds and reservoirs inhabiting C. subtilis. Further the thesis shows how C. subtilis can cope with deviations from mean water level fluctuations. In summary important fundamental knowledge for the sustainable conservation and promotion of C. subtilis, particularly in secondary habitats, has been established.

La mise en place de réseaux écologiques est considérée comme l'un des moyens de pallier aux effets néfastes de la fragmentation sur la biodiversité. Dans les paysages agricoles, les éléments linéaires non cultivés peuvent constituer de larges réseaux, et jouer un rôle d'habitat-refuge et/ou de corridor de dispersion pour les espèces végétales. L'objectif de cette thèse est de comprendre quel rôle un réseau dense de fossés de drainage peut jouer dans le maintien et la dispersion d'espèces végétales dans un paysage agricole intensif du nord de la France. Nous avons également cherché à savoir dans quelle mesure les caractéristiques du paysage, la connectivité du réseau et les traits d'histoire de vie des espèces végétales impactent la dispersion des propagules au sein du réseau de fossés. Nos résultats montrent que les fossés jouent bien un rôle de corridor écologique pour les espèces végétales. En ciblant plus précisément les espèces hydrochores, nous avons démontré qu'elles dépendaient essentiellement de la composition et de la connectivité du réseau de fossés et des éléments immédiatement adjacents aux berges. Le réseau détermine également la structuration des flux de gènes chez deux espèces végétales de berges de fossés. Enfin, nos résultats montrent que la réponse des espèces à un gradient de connectivité du réseau dépend d'une combinaison de traits de dispersion, et qu'une diminution de cette connectivité entraîne une convergence fonctionnelle de ces traits à l'échelle de la métacommunauté. L'ensemble de ces résultats permet de mieux comprendre le rôle de corridor des fossés pour les espèces végétales, afin de permettre leur intégration au sein des projets de continuités écologiques dans les paysages agricoles. / The establishment of ecological networks is considered as one of the solutions to mitigate the negative effects of fragmentation on biodiversity. In agricultural landscapes, non-crop linear elements may form large networks, and constitute refuge habitats and/or dispersal corridors for plant species. The objective of this study is to understand which role may a dense drainage ditch network play for the maintenance and dispersal of plant species in an intensive agricultural landscape located in northern France. In addition, we also investigated the impact of landscape characteristics, network connectivity and plant species life-history traits on propagule dispersal within the ditch network. Our results indicate that ditches are indeed ecological corridors for plant species. By focusing more specifically on hydrochorous species, we demonstrated that they essentially depend on ditch network composition and connectivity and on elements immediately adjacent to the banks. The network also drives patterns of gene flow for two ditch bank plant species. Finally, our results also indicate that species’ response to ditch network connectivity depends on a combination of dispersal traits, and that connectivity reduction leads to functional convergence of those traits at the metacommunity scale. Together, these results provide a better understanding of the corridor role of ditches for plant species, in order to include these features into ecological network planning in agricultural landscapes.

Long-distance dispersal of Rumex alpinus was studied in the Giant Mountain in the National Park. The invasion of R. alpinus is there kind of problem. The work builds on a thesis from year 2007 (20007 Červenková), in which was made the model of the invasion of R. alpinus in the area of the Giant Mountain. The measurements of the seeds spread take place at four localities, three of them were for measuring of water dispersal and one was for measuring of winter dispersal. Anemochory was measured using traps in the meadow up to a distance of 50 m. The seeds were dispersed by wind to a distance of 20 meters. Hydrochory was measured using a network's traps in the streams up to 100 m. The largest measured water dispersal was 100 m. Hydrochory therefore proved to be an important factor, which influenced the invasion of R. alpinus. The storms and flood had the great influence on the hydrochory and anemochory. The prediction exponential curves were compiled from the data about the wind dispersal. The curves express the spread to more than a measured distance. The field dispersion curves were compared with theoretical curves, which were used in the model of the invasion from 2007. It turned out that the theoretical curves overestimate the spread of R. alpinus by wind. The dispersion of seeds was underestimated in the...

Coleanthus subtilis ist eine durch die FFH-Richtlinie geschützte, weltweit sehr seltene Art, welche periodisch trockenfallende Standorte in Flussauen (Primärhabitate) bzw. durch den Menschen geschaffene Staugewässer (Sekundärhabitate) besiedelt. Die Erarbeitung der aktuellen Verbreitungsbilder der Art in Sachsen und ihrer Besiedlungshistorie waren Ausgangspunkt für die Analysen zur Ökologie dieser Art. Anhand von Analysen zu den Ausbreitungsmechanismen, Standortansprüchen und Reaktionsmöglichkeiten von C. subtilis wurden grundlegende Beiträge zum besseren Verständnis der Strategien dieser Art erbracht. Die Arbeit gibt Hinweise für eine artenschutzgerechte Bewirtschaftung der Staugewässer insbesondere für die Regulierung von Zeitpunkt, Dauer, Intensität und Häufigkeit von Wasserstandsabsenkungen sowie hinsichtlich einzelner Praktiken im Zusammenhang mit einer fischereilichen Nutzung. Weiterhin zeigt die Arbeit auf, wie C. subtilis auf bestimmte, von den durchschnittlichen Wasserstandsschwankungen abweichende, Bedingungen reagieren kann. Damit sind nun wichtige Grundlagen zum nachhaltigen Schutz und zur Förderung von C. subtilis, insbesondere in Sekundärhabitaten, vorhanden. / Coleanthus subtilis is a globally rare species protected by the European Union Habitats Directive. This grass establishes on periodically drying sites in river floodplains (primary habitats) but also in man made ponds and reservoirs (secondary habitats). The identification of the present distribution patterns as well as the reconstruction of the colonisation history of C. subtilis in Saxony were the basis for analyses about the ecology of this species. By analysing dispersal mechanisms, habitat demands and response traits of C. subtilis fundamental contributions to a better understanding of the strategies of this species are given. The thesis provides information about optimum time, duration, intensity and frequency of water level reductions and about the consequences of different management practices particularly with respect to fishery in ponds and reservoirs inhabiting C. subtilis. Further the thesis shows how C. subtilis can cope with deviations from mean water level fluctuations. In summary important fundamental knowledge for the sustainable conservation and promotion of C. subtilis, particularly in secondary habitats, has been established.

Many plant species are closely related to river biotopes or to biotopes influenced by rivers. River systems create important linear corridors in ecosystems and directly or non-directly influence spatial spread of species in these environments. This offer many questions about species spread in this system. We can answer these questions by using molecular methods. Using 10 microsatellite (SSRs) primers, 202 individuals of Phragmites australis from 60 populations were analysed. Those analyses allowed reveal kinship of individuals, obtain information about spatial spread of populations and about spreading of common reed. Phragmites australis creates both - monoclonal and polyclonal - populations. Dependence of rate of clonality on environment was revealed. Populations from river banks are more monoclonal, populations from pond shores are more polyclonal. Populations are isolated. The highest percentage of variability was explained on among-population level. This is common for anemochoric species. Communication between populations is present, more on shorter distances. Evidence for vegetative spread was found on short distance. Generative spread is much more common. Long-distance spreading is mediated by generative diaspores - seeds. This spreading includes within-river spread, among-river spread and spreading...