This thesis focuses on the changes of vegetation of the wet meadows in Slavkovský Les during past decade. It uses data on vegetation gained from 100 permanent plots. By the analysis of the species composition and diversity it aims to elucidate the changes of the wet meadows over the last ten years. It aims to define, which are declining and which are becoming more common. Applied management should have a great impact on the observed vegetation changes so its effect is studied in the thesis as well. The knowledge of the suitable management should lead to conservation of the local biodiversity. The abiotic environmental factors are important as well as they can influence the species composition. These factors were studied by the application of Ellenberg indicator values on the species present in the study. These changes were compared in time and in a combination of time with a management type. Thus, we should be able to say how the environment has changed in the past decade and whether the type of management has any effect on the changes. Furthermore, the thesis explores whether changes in species composition over time may be explained by species traits. The results indicate that the species diversity and composition have indeed changed during the past decade. Apparently, the higher amount of...

Palatability of 20 meadow plant species was assessed in the slug grazing experiment conducted. Monocots exhibited significantly lower palatability than dicots. Litter decomposition rate was assessed in the field litter-bag test. Linear regression analysis was performed to answer the main question whether species palatability is related to litter decomposition rate and whether it is determined by the carbon or nitrogen content. Phylogenetically independent contrasts were used to eliminate correlated phylogeny effect. Regression trees were used to detect the effect of species traits on species palatability and litter decomposition rate.

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La mise en place Trame Verte et Bleue sur le territoire français a pour vocation de garantir la connectivité fonctionnelle entre habitats. C’est une des réponses politiques qui vise à enrayer le déclin actuel de la biodiversité, lie notamment à la destruction et à la dégradation des habitats. L’objectif de cette thèse est de quantifier l’effet de la connectivité, au regard d’autres facteurs environnementaux, sur la diversité des communautés et la diversité génétique des papillons de jour dans trois régions agricoles. Deux approches sont utilisées pour comprendre les processus qui sous-tendent ces patrons de diversité : i) l’étude de la communauté dans son ensemble et des groupes écologiques qui la compose, ii) l’étude de la résistance des milieux a la dispersion par génétique du paysage sur une espèce : le Myrtil (Maniola jurtina L.). Les résultats montrent que même si les caractéristiques locales jouent un rôle plus fort, la structure du paysage influence la composition des communautés. Ainsi, la quantité de terres arables réduit la richesse spécifique, la diversité génétique, et les flux de gènes chez le Myrtil. Les prairies hébergent des communautés diversifiées, incluant des espèces peu fréquentes. Les éléments linéaires enherbes supportent des communautés appauvries, mais favorisent la dispersion et la diversité génétique du Myrtil. La diversité des papillons est plus forte a proximité de boisements : les papillons pourraient bénéficier de ressources sur les lisières ; par ailleurs, les milieux boises semblent à la fois limiter les flux de gènes du Myrtil tout en accroissant sa diversité génétique. La complémentarité des milieux soulevée ici nous invite à repenser le modèle classique en ≪ sous-trames ≫ indépendantes de la Trame Verte et Bleue. Selon les enjeux de conservation, les espèces et les contextes paysagers, il est nécessaire de distinguer les situations ou, parmi un panel d’actions envisageables, améliorer la connectivité est une solution pertinente. / The implementation of the “Green and Blue Infrastructure” in France intends to ensure the functional connectivity of habitats (green veining). It is one of the nature conservation policies which aim to reduce the loss of biodiversity caused by the destruction and degradation of natural habitats. The objective of this work was to quantify the impact of connectivity, in comparison to other environmental factors, on the diversity of butterfly communities and their genetic diversity in three French agricultural regions. Two different approaches were applied to understand the underlying processes driving these diversity patterns: i) the study of the whole community and of the different ecological groups, ii) the study of landscape features resistances to butterfly dispersal using a landscape genetics approach on one species: the Meadow brown (Maniola jurtina L.). Our findings show that although local characteristics play a dominant role, landscape context does have an influence on community composition. Arable land cover decreases species diversity, and the Meadow brown genetic diversity and gene flow. Grasslands support more species rich communities, including non-frequent species. Grassy linear landscape elements host impoverished communities, but improve Meadow brown dispersal and enhance its genetic diversity. Species diversity is higher within grasslands in proximity to woody habitats: butterflies may benefit from resources on forest edges; moreover, woodlands seem to limit Meadow brown dispersal while increasing its genetic diversity. The habitat complementarity we evidenced here led us to question the classic model of ecological continuities as a collection of independent sub-networks, one for each type of habitat. According to conservation issues, species under interest and landscape contexts, we also need to identify situations where, among a broad panel of possible conservation actions, increasing connectivity is the most effective solution.

No description available.

The study is focused on comparative ecology of three closely related species from Myosotis palustris group. Importance of various functional traits of individual species was evaluated experimentally in the greenhouse (germination experiments), in the pot experiment and in the reciprocal transplant field experiment. Germination, production of clonal structures and response to various environmental conditions (competition, moisture conditions, etc.) were studied. The experimental data are supplemented with an analysis of phytosociological relationships of the studied species.

Abstract Ecological research based on both species and their traits help us to understand the main mechanisms and environmental factors structuring biological communities. In general, variation in community composition is thought to be a consequence of both stochastic and deterministic factors. In stream ecology, the traditional view has been that the local habitat conditions pose a strong environmental filter that selects only species with the right functional traits into the local communities. However, recent studies on streams have also suggested that the responses of species to environmental gradients may be independent of those of other species due to stochastic factors, such as species dispersal, which then result in more continuous communities along environmental gradients. The aim of this thesis was to explore the relative importance of the deterministic and stochastic factors in the structuring of taxonomic and functional trait-based macroinvertebrate communities in streams in a high-latitude catchment by comparing the variation in these community facets along environmental and spatial gradients. Also, the relationship between environment and the functionally-defined communities was explored closely. The results indicated how the taxonomic composition of the communities may be more closely related to the stochastic and dispersal-related factors, whereas the functional composition of the communities may be more closely related to the deterministic environmental filtering processes. However, the overall structure of the communities seems to be strongly controlled by the variation in environment, although the heterogeneous and harsh conditions of the streams may preclude the formation of predictable community types. Nonetheless, some noticeable responses of different traits to different environmental factors were found, suggesting that definable functional trait-environment relationships may be discovered if key traits of the species can be identified. Overall, these findings underline the benefits of describing both taxonomic and functional-based communities when exploring the mechanisms behind the structuring of macroinvertebrate communities. The results also have applications for conservation practices. Conservation efforts should focus on varying environmental conditions in order to cover all aspects of macroinvertebrate community variation. / Tiivistelmä Lajeihin ja lajien toiminnallisiin lajiominaisuuksiin pohjautuva ekologinen tutkimus tuo uutta tietoa biologisten yhteisöjen taustalla vaikuttavista tekijöistä. Yleisesti yhteisöjen rakentumiseen vaikuttavat niin deterministiset kuin stokastiset ympäristössä vaikuttavat tekijät. Virtavesiyhteisöjen on perinteisesti ajateltu rakentuneen niin sanottujen ympäristösuodattimien mukaisesti, jolloin ympäristön vaihtelu suodattaa tietynlaisiin ympäristöihin vain lajit, joilla on tarvittavat ominaisuudet paikalla selviytyäkseen. Useat viimeaikaiset tutkimukset ovat kuitenkin osoittaneet virtavesiyhteisöissä elävien lajien esiintymisen vaihtelevan ympäristössä myös itsenäisesti erilaisista stokastisista, kuten lajien dispersaaliin vaikuttavista, tekijöistä johtuen. Tässä väitöstutkimuksessa tutkin näiden determinististen ja stokastisten ympäristötekijöiden suhteellisia vaikutuksia taksonomisesti ja toiminnallisesti luokiteltujen pohjaeläinyhteisöjen rakentumiseen pohjoisissa virtavesissä. Myös yksittäisten lajiominaisuuksien ja toiminnallisten yhteisöjen suhde pohjoisten virtavesien ympäristöolosuhteisiin oli tarkastelun alla. Tutkimuksen tulokset antoivat viitteitä siitä, että ympäristössä toimivat stokastiset ja lajien dispersaaliin liittyvät tekijät vaikuttaisivat voimakkaammin taksonomisesti luokiteltujen yhteisöjen vaihteluun, kun taas toiminnallisesti luokitellut yhteisöt vaikuttaisivat rakentuneen enemmän determinististen ympäristöprosessien mukaisesti. Kokonaisuudessaan yhteisöt vaikuttaisivat kuitenkin rakentuneen voimakkaasti vaihtelevien ympäristöolosuhteiden ohjaamana, ja tämä vaihtelu voi estää selkeästi ennustettavien yhteisörakenteiden synnyn. Muutamia selkeitä lajiominaisuusvasteita kuitenkin löytyi, mikä antaa viitteitä ennustettavissa olevien toiminnallisten yhteisöjen olemassaolosta, mikäli yhteisöjen menestymisen kannalta merkittävimmät lajiominaisuudet vain osataan määrittää. Nämä tulokset osoittavat, miten sekä taksonomisesti että toiminnallisesti luokiteltujen yhteisöjen käyttäminen rinnakkain yhteisöekologisissa tutkimuksissa voi auttaa selventämään yhteisöjen synnyn taustalla vaikuttavia tekijöitä. Tuloksilla on merkitystä myös virtavesiyhteisöjen suojelun kannalta. Suojelutoimenpiteet tulisi kohdistaa kattamaan ympäristöolosuhteita laajasti, jotta ympäristöolosuhteiden mukaan vaihtelevat yhteisöt tulisivat parhaalla mahdollisella tavalla katetuiksi.

Species with particular traits are not randomly distributed across landscape. Habitats provide the templet on which evolution forges characteristic morphologies and life-history strategies and environmental determinants in an ecological processes represent a filter for certain species with appropriate traits. It is essential to understand how spatial differences in community composition are affected by geographical patterns in a distribution of species characteristics. I was interested in searching and determining the relationships between species traits and environmental parameters within avifauna of south Africa. I investigated the effect of which variables of environment most influenced bird assemblage composition and distribution of species traits in space. Relationships between the environmental factors and the species traits and life-history stategies were investigated using RLQ analysis, a multivariate ordination method able to relate a species trait table to an environmental table by way of a species presence/absence table. The first axis of the RLQ analysis was highly statistically significant and explained most of the variability. It was strongly positively related to increasing productivity, to atributes reflecting vegetation character and to availability of water sources. The rest of...

Each species has specific adaptations to its environment, and since environmental parameters reveal geographic trends, it is reasonable to expect the existence of geographic trends in species characteristics as well. The aim of this study has been to evaluate the effect of environmental conditions on geographic variability of functional traits of European birds. I have analysed the effect of temperature, precipitation, productivity, altitude and habitat type (forest, open habitats, bush, settlements, wetlands) on clutch size, number of clutches per breeding season, egg size, incubation length, age of maturity, body mass, wing, tail, bill and tarsus length. I have used data from the European breeding bird atlas, so that I have calculated mean values of all the traits for quadrats 50x50 km, and then related them to environmental characteristics using OLS and GLS. Clutch size increases with temperature, whereas the number of clutches decreases with it, indicating possible trade-off between clutch size and the number of clutches, whose result is determined by the length of breeding season. Egg size decreases with temperature, possibly due to higher survival of large eggs (and consequently juveniles) in cold regions. Incubation length increases with both temperature and environmental productivity,...

Semi-natural grasslands of the eastern Moravia have big potential to host species-rich plant communities. However, changes in land-use during the second half of the last century were rapid and vast and many grasslands had been ploughed over. In the early 80s some arable lands were sown with low diversity clover-grass mixture and transferred back to grassland. Restoration of grasslands on former arable fields is a major challenge. Their colonisation by grassland species may be complicated by initial seeding productive low diversity seed mixtures. The aim of this study was to estimate differences in species composition and species diversity between ex-arable artificially seeded grasslands and fragments of grasslands with continuity over 70 years in the north part of White Carpathian Mts., SE Czech Republic and identify species traits limiting species ability to colonize the ex-arable grasslands. Target plant species (total of 137) were surveyed on 66 grasslands. Surveyed grasslands were according to continuity and type of management. Coordinates of centroids from each polygon (i. e. surveyed grassland) were used to treat the spatial correlation of the surveyed grasslands. The effect of continuity on species composition and diversity was tested after accounting for differences in the management and...