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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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Fern (Pteridopsida) flora of South Nyírség (East Hungary)
162–182Views:381The study presents a number of new data on the fern flora of South Nyírség, and reviews all available literature and herbarium fern records from the area. A total of 19 Pteridopsida species were detected in the region. The hart's tongue fern (Asplenium scolopendrium) and the soft shield fern (Polystichum setiferum) were hitherto unknown in the whole Nyírség region (flora district “Nyírségense”). The broad buckler-fern (Dryopteris dilatata), scaly male fern (Dryopteris affinis) and floating fern (Salvinia natans) are new records to the area of South Nyírség. Dryopteris dilatata has been found in a surprisingly great number of localities. Some morphological characters facilitating identification of this species are also discussed. The local pine plantations, fens, carrs and humid deciduous forests are important habitats for ferns. In some localities the co-occurrence of 5-6 fern species were observed. The increasing aridity in the last decade is posing a serious threat to ferns in the area.
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Literature reviews
109-110Views:187Bartha D. (szerk.) (2019): Vörös Lista – Magyarország fa- és cserjefajai. Soproni Egyetemi Kiadó, Sopron, 59 pp. ISBN 978-963-334-328-9
Bartha D. (szerk.) (2020): Fekete Lista. Magyarország inváziós fa- és cserjefajai. ● Szürke Lista. Magyarország potenciálisan inváziós fa- és cserjefajai. Soproni Egyetemi Kiadó, Sopron, 84 pp. ISBN 978-963-334-357-9
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Rubus armeniacus Focke, an unnoticed invader in the Hungarian flora
220-228Views:115The authors report on the occurrence, distribution and invasion potential of Rubus armeniacus, a bramble species of Caucasian origin, in Hungary. The first verified records of the species are from the 1990s. It has established strong populations in ruderal habitats mainly around Budapest and some other cities, whereas its competiveness is rather weak in closed non-lowland forests rich in native bramble species. In terms of conservation, it constitutes a real threat to the vegetation of Pannonian sandy habitats. The results of this study also emphasize the importance of recognising "nonnative cryptic species" for ecology and conservation biology.
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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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Research on the distribution of woolly cup grass (Eriochloa villosa) in the northern part of Borsod-Abaúj-Zemplén county, Hungary
27–32Views:503Eriochloa villosa (Thunb.) Kunth was recorded for the first time in Hungary in 2007. Since then, the species spread intensively in the area and appeared at some other parts of Hungary. We carried out a research at the current distribution range of the species in the northern part of Borsod-Abaúj-Zemplén county. We asked how big is the infested area surrounding the place of the first occurrence and whether other occurrences could be found in other parts of the investigated area. This article also gives a review on its known localities in Hungary and neighbouring areas. During the field research, 58 locations of the species were identified, it occurred mainly in ploughed and unploughed agricultural fields, and at some places in disturbed grasslands, too. It has spread on a large scale around the neighbouring areas of the first location found in 2007. Other locations were also found even at more distant places such as in the valley of the Sajó and Bódva rivers and in the Cserehát region. This means that further spread of Eriochloa villosa can be expected, especially in areas with an intensive agricultural activity, in disturbed grasslands, and a threat of its appearance is also suspected in open natural habitats.