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• Water contraction drives stronger the formation of diatom assemblages in stream than human induced microhabitat-variability

  211-228

  Stefánia Kiss

  Zsuzsanna Nemes-Kókai

  Áron Lukács

  Enikő Török-Krasznai

  Viktória B-Béres

  Views:

  211

  Today, 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.

• Monitoring of the Apium repens population near Császártöltés (2006–2015)

  1–8

  András Kun

  Views:

  168

  Detailed botanical surveys were carried out to monitor the population size of Apium repens in the Vörös-mocsár nature protection area (located in S Hungary, Császártöltés). We found a clear correlation between the water status and the land use type and management of the habitats and the size of the Apium repens population. Apium repens is a Nanocyperion-species, which simultaneously requires wet and open surfaces. Its population shrinks, becomes latent or disappears if its habitat dries out or any other radical transformation happens, like too much leaf litter, closure of the vegetation, or succession on the open peat surfaces. Proper management (water retention, extensive grazing, mowing, open peat surface) has a very positive effect on the populations in a short time, even within a growing season. The research was implemented within the framework of the National Biodiversity Monitoring System, in cooperation with the Kiskunság National Park Directorate.

• Data to the flora and geobotany of Kisalföld (Lesser Plain) region, NW Hungary

  235-253

  Gergely Király

  Gábor Takács

  Angéla Király

  Views:

  132

  Lesser Plain (Kisalföld) – divided among three countries (Austria, Hungary and Slovakia) – is the westernmost part of the lowland areas of the Pannonian Basin. Present paper provides a résumé of the authors’ floristic work from the Hungarian part of the area, describing localities, habitats and regional phytogeography of 57 taxa altogether. The localities were listed according to the classification of small geographic regions. The most important results of the study are as follows:

  • We recorded 5 species new to the region (Brachypodium rupestre, Bromus ramosus, Hypericum dubium, Lathyrus sphaericus, Tordylium maximum); all of them can be considered as submontane-montane elements.
  • We reported several species new to a microregion within the Lesser Plain: montane species in the W-SW part of the Plain (Cirsium rivulare, Dryopteris dilatata, Equisetum telmateia), loess-connected species mainly on the Moson Plateau (Agropyron cristatum, Allium atroviolaceum, Euphorbia salicifolia, Viola ambigua); and occurrences of species on sandy soils near the Lake Fertő (Draba nemorosa, Stipa pennata).
  • We explained the known localities of several salt tolerant species (e.g. Carex divisa, Crypsis alopecuroides, Juncus maritimus, Limonium gmelinii, Suaeda pannonica) from the Lake Fertő and its surroundings.
  • We assessed the role of the forest management and nature conservational actions in the distribution of some important tree species (Acer tataricum, Betula pubescens, Fraxinus ornus, Quercus petraea, Salix pentandra).
  • We discussed the regional nature conservational status of several protected and/or threatened species (e.g. Allium carinatum, Allium suaveolens, Carex strigosa, Hottonia palustris, Potamogeton coloratus, Stellaria palustris) in the Lesser Plain.

  The activities of the authors in the surroundings of Győr were supported by monitoring results gained during the Hungarian Little Plain project (LIFE08 NAT/H/000289).