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The occurrence of Pterygoneurum squamosum Segarra et Kürschner on a reclaimed waste storage near town Győr (NW Hungary)
23-27Views:107In the article a new locality, range map and habitat description of Pterygoneurum squamosum is provided from Hungary. Differently from up to the present known localities, the moss was found on anthropogenic habitat, eroded and clayey soil surface. Considering the climatic and soil conditions there, probably this rare Mediterranean species has wider ecological tolerance, so we come across it on further man-made habitats, as well as on loess walls.
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Distribution of Calamagrostis stricta (Timm) Koeler in the Southern Nyírség (E Hungary)
188-196Views:145This study presents the current distribution of narrow small-reed (Calamagrostis stricta (Timm) Koeler) in the southern part of Nyírség (E Hungary). Beyond the efforts to confirm previously known occurrences, a high number of potential habitats were surveyed. Field work was carried out from late autumn to early spring taking advantage of the better perceptibility of dry foliage. The species was detected in 43 localities inside the boundary of 15 settlements, which considerably exceeded our expectations. Although most of the populations were quite small, in some cases their extent reached over 1000 m². Populations around the settlements of Penészlek, Fülöp and Nyírábrány were the most frequent and the largest in size. The endangered status of the species is caused by the insufficient water supply of suitable habitats in the region. Besides habitat change, desiccation can also amplify the effect of anthropogenic disturbances (e.g. ploughing, fishpond development), which poses a further threat to populations.
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Orchids of poplar plantations – a review
102–117Views:726124There are literature data on the occurrence of 26 orchid species and 2 hybrids in economic poplar plantations from 13 European countries. The occurrence of 4 additional species in poplar plantations in 3 countries is proved by sources on the World Wide Web. The most widespread orchids in the poplar plantations are the rhizomatous, partial myco-heterotroph Cephalanthera and Epipactis species. Their importance is enhanced by the fact that most of the known populations of some species with a relatively narrow distribution range (Epipactis bugacensis, E. campeadorii, E. fibri, E. tallosii, E. zaupolensis) are known in poplar plantations. Cultivated poplar monocultures are likely to provide habitat for further orchids in other countries too. Most of the published papers are limited to floristic data from a single or a few plantations. Longer-term observations are only available from Poland, thanks to the work of W. Adamowski, and these suggest that populations may persist for decades and even increase dynamically. The size of orchid populations in some cases can reach thousands or even hundreds of thousands of individuals. Orchids can appear earliest in (4–)7–8 years old plantations. Very little is known about how the cultivation, structure, soil conditions and the poplar cultivars influence the presence of orchids. Mycorrhizal interactions of poplars and orchids may play a key role in this process, but the available knowledge is very limited. Furthermore, little is known about how the economic use of plantations can be reconciled with the long-term maintenance of orchid populations.
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Water contraction drives stronger the formation of diatom assemblages in stream than human induced microhabitat-variability
211-228Views:205Today, climate change, together with other anthropogenic influences is considered as a major threat affecting aquatic ecosystems in several ways. Here, altering water contraction (standing and flowing phases) and human-induced habitat variability (natural and artificial stream sections) were studied as modifying factors driving community changes in benthic diatom assemblages of a Hungarian small lowland stream (Létai-ér). We assumed notable compositional differences between phases and habitats, but we expected these differences to decrease with drying. Moreover, lower diversity was hypothesized in assemblages of both artificial section and flowing phase. While taxonomic composition did not reveal significant differences between the sections, well pronounced compositional changes were found between phases. Surprisingly, no significant diversity changes were observed during water contraction. Compared to the natural microhabitat, however, artificial stream section was found to maintain more diverse diatom community. These results emphasize that modification effects of climate change induced hydrological extremes can lead to remarkable compositional changes in benthic algal assemblages even on a short time scale, that must be taken into account in both water management and nature conservation strategies.