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Water contraction drives stronger the formation of diatom assemblages in stream than human induced microhabitat-variability
211-228Views:235Today, 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.
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Contributions to the algal flora of a recently-formed peat moss bog near Kőszeg (W Hungary)
113–130Views:388The Alsó-erdő peat bog near Kőszeg has undergone a significant transformation since its first mention in the literature. In addition to the original single patch, a smaller one appeared a few decades later. The process did not stop and a third unit, discussed here, was formed. The succession of its macrovegetation towards the typical peat moss association started slowly but surely, due to balanced water regime and other optimal environmental conditions. The process is more advanced for the algal vegetation, which shows the characteristics of peat bogs already. The high species diversity found makes the habitat highly valuable itself. Although a special, unique algal species has not been found in previous studies, 27 Desmidiales taxa listed as endangered occur sometimes with high density and make the habitat even more valuable. Based on our results, the area deserves special attention both from the habitat conservation and research point of view. At the same time, its further monitoring can provide crucial information for exploring and understanding the succession of similar habitats, and thereby for their more efficient protection.
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Distribution of Calamagrostis stricta (Timm) Koeler in the Southern Nyírség (E Hungary)
188-196Views:164This 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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Data to the flora of Sopron Hills and its foreground
239-242Views:119The present study reports additional records to the flora of Sopron Hills and Sopron Basin. The records were collected during our field surveys between 2010 and 2014 and contain occurrence data of 19 vascular plant taxa. The genus Orobanche is represented by 5 species. Two taxa are new for the flora of Sopron Hills (Amaranthus blitoides, Orobanche teucrii), others are interesting because of their old or uncertain indication (e.g. Dianthus superbus, Myosotis sparsiflora, Orobanche lutea, Orobanche purpurea).
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Notes to the vascular flora of Sopron Mountains and its foreground
187–194Views:338Records of 26 vascular plant species from the territory of Sopron Mountains (16 species) and Sopron Basin (11 species) are presented. Our field works (between 2014 and 2020) focused on some localities at the eastern and southern parts of the region. Tetragonolobus maritimus is new for the Sopron Mts, whereas Ajuga chamaepithys and Lycopsis arvensis are new for the Hungarian part of the hills. Some protected plants like Agrostemma githago, Gentianopsis ciliata and Sesleria uliginosa were rediscovered in the region. Comments about all species and their local chorology are added. A remarkable degradation process of bogs around Harka village, caused mainly by insufficient water supply of meadows, was observed. The spread of occurrences of several naturalized weed such as Aegilops cylindrica, Galium parisiense, Geranium rotundifolium, Kochia scoparia, Lepidium virginicum, Oenothera salicifolia, Sagina apetala subsp. apetala and Verbascum lychnitis was noticed. The most surprising observations refer to Galium parisiense; the spread of the species by transport had no precedent in Hungary before.
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The degradation of hygrophilous plant associations of the Nyárjas Lake (E Hungary)
63–77Views:131The Nyárjas Lake (located near Kállósemjén, East Hungary) was one of the most typical bogs in the Nyírség until the early 1980’s. Most of its area was covered by the association of Carici-Menyanthetum. The number of species characteristic to the mentioned association was generally high. As the climate became drier, hotter and were characterised by higher magnitude of extremities, the water coverage became no longer as permanent. This resulted that the Menyanthes trifoliata and Listera ovata became extinct by 2000. Lemno-Potamea species were not found after 2010. Bidentetalia, Calystegietalia, Chenopodietea and Secalietea species became more prevalent, particularly in drier periods, and locations where Carici-Menyanthetum used to be characteristic. Cirsium arvense in the mid-1990’s and that of Urtica dioica in the mid-2010’s became dramatically abundant. Both the number and coverage of species indicating habitat degradation have increased. The composition of wet meadow plant associations shifted towards the drier Arrhenatheretea. A moderate revitalisation of wetland associations was, however, observed coinciding years with higher precipitation.