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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.
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New occurences and spread of the adventive species, Torilis nodosa in Hungary
26-31Views:655Torilis nodosa (L.) Gaertn. is an Atlantic-Mediterranean weed species. Its old data are known from Budapest, but these may have been occasional occurrences, the species has not been confirmed in Hungary for more than a hundred years. In the last few years, we have found six new occurrences of the species in Hungary, one population in Budapest, and another five in some settlements on the northern shore of Lake Balaton. The species was observed in ruderal or intensely mowed urban habitats, in all cases. Intensive tourism has a role in its introduction for sure, but for the survival of self-sustaining stands and in its already perceptible regional spreading, the climate change trends, the increasingly mild winters, and the decreasing number of frost days could also be important. New data from Hungary are well connected to its other Central European observations.
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Contributions to the escaped, naturalised and potentially invasive species of the Hungarian adventive flora
111-156Views:545In this paper we compiled data on 157 Hungarian adventive plant species – of which 65 had not been reported from the country previously – from 47 settlements of Transdanubia and the Great Hungarian Plain. These taxa are rare, interesting or not included in the most recent list of the Hungarian neophyte species. The list includes data about many rare, occasionally escaping species (e.g. Lagurus ovatus, Salvia coccinea), taxa considered incapable of reproduction under the recent climatic conditions of the Pannonian Basin (e.g. Cupressus sempervirens, Punica granatum) or naturalised plants that may become invasive in the future (e.g. Celtis sinensis, Lonicera japonica). In the outlook we highlighted some special urban habitats (e.g. private and botanical gardens) and practices (e.g. public green space management) that endanger the native flora. We also describe their role in promoting the appearance and the expansion of alien plant species, and processes (e.g. laurophyllisation, spread of thermophile species) that will become increasingly common in the future as a result of climate change.
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Contributions to knowledge on the distribution of nine adventive or invasive algae species in Hungary
11-21Views:111Hungarian records of nine adventive or invasive algae [Didymosphenia geminata, Nitzschia closterium, Reimeria sinuata, Navicula schroeteri, Pleurosira laevis (Bacillariophyceae); Pediastrum simplex (Chlorophyceae), Cylindrospermopsis raciborskii, Cuspidothrix issatschenkoi, Sphaerospermopsis aphanizomenoides (Cyanobacteria)] are presented. Navicula schroeteri Meister is a new species for the Hungarian flora. Although the observed distribution patterns of these species were very different, the increasing frequency of their appearance indicates significant effect of climate change on abiotic environment of inland waters, such as the increase in water temperature, increase in salt concentration, and eutrophication. The significance of continuous biomonitoring is emphasized, which, through the recognition of natural and human-induced changes in species composition of algae, or the appearance and rapid expansion of non-indigenous species, can detect environmental changes of inland waters.
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The degradation of hygrophilous plant associations of the Nyárjas Lake (E Hungary)
63–77Views:108The 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.
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Multiclavula mucida (Basidiomycota) and other cryptogamic taxa in the Hungarian flora
173–184Views:220The paper deals with the species found during cryptogamic flora mapping in 2023 that are remarkable from a floristic, taxonomic or conservational point of view. We present data from the Bükk Mts of two Trapeliopsis species which appear to be rare in Hungary. Multiclavula mucida, which is apparently a rare basidiomycete lichen species in Europe that prefers humid, montane habitats was discovered in the Mecsek Mts as a new species for the Hungarian flora. Of the knothole moss, Anacamptodon splachnoides, which is now thought to be entomophilic, we communicate the only extant population from Southern Transdanubia. We report the first occurrence of the atlantic-mediterranean Leptodon smithii from the Hungarian side of the Great Hungarian Plain. Numerous data of the corticole Neckera pennata indicate that in Hungary the distributional centre of this species is situated in the county of Baranya in the lowlands. New data from the Bükk Mts underline that in the Pannonian region Buxbaumia viridis is primarily a terricole species of acidophilous beech forests. We communicate the first occurrence from the lowlands of the alien lignicolous Sematophyllum adnatum which is dangerously spreading in Europe, at the same time one of the most vigorous populations in the Pannonian region. The third Hungarian occurrence of Callicladium haldanianum, a species that seems to spread in bogs, as well as the second occurrence of Racomitrium lanuginosum, growing abundantly on an andesite boulder scree in Mátra Mts, are also reported here. Of Phegopteris connectilis we present in photographic documentation the first extant population from Southern Transdanubia, and we discuss whether the first publication from Mecsek Mts is correct or exact. In addition to listing the floristic data, we also briefly discuss the (mis)use of distribution data in the context of climate change, the difficulties of distinguishing the microtaxa of some pteridophytes, e.g. Asplenium adiantum-nigrum agg. and Dryopteris affinis agg., and we correct one of our previously published, erroneous Hedwigia stellata data. Some interesting data of other taxa (such as Leucobryum glaucum, Palustriella commutata, Tetraphis pellucida, Gymnocarpium robertianum, Ophioglossum vulgatum) are also mentioned in the paper.
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The Himantoglossum adriaticum Baumann in the East-Zala hills (W Hungary)
297–303Views:74This paper presents five new localities of the rare and threatened orchid Himantoglossum adriaticum in Zala county. The new localities falls within the known distribution area of the species. The population size on newly found locations are extremely small, in most cases only 1 generative individual were observed in the mesophilic secondary grasslands of abandoned vineyards. Highly possible, that this species shows a slow, but detectable expansion in Hungary, maybe due to recent climate change process.
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Contributions to the algal flora of a recently-formed peat moss bog near Kőszeg (W Hungary)
113–130Views:367The 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.