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Kaszálás felhagyásának kezdeti hatása nyugat-magyarországi üde gyepek fajkompozíciójáradhdhdh
13-20Views:100In our survey we collected data about the behaviour of dominant species on three wet meadows in the West part of Hungary. We focused on species composition, the stability and economic values of the grasslands affected by abandonment and mowing. The meadows are mowed twice a year since 2006. We established abandoned plots (50×50 m) within each meadows in 2012 to investigate how can the species composition shifts by abandonment comparing with the mowed plot. In this study we investigated the abundances of species in 2×2 m quadrates (10 per plot) in three times per a year (April, June, August) in 2012 and 2013. Total species lists are similar (55 ± 6% common species in paired comparison) on the three grasslands, however the reaction of dominant species on mowing and unmowing were different, probably due to also the significant differences in the abundance of dominant species between meadows. The abundance of Festuca arundinacea decreased on every abandoned plot from 2012 to 2013, while the effects of abandonment were different on the abundance of Poa angustifolia. The abundance of Cirsium canum was higher in every mowed and also in every unmowed plot in 2013 than a year before. Comparing the three grasslands the abundance of primary grasses, stinger plants and legumes species were significant different in both investigated years. The significant differences in the abundance of dominant species among grasslands were presumably not only caused by the differences in the applied treatments but also the effects of environmental factors.
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The role of haphazardly executed conservation treatments in the preservation of botanical values on the shore of Lake Balaton
21-23Views:85Most semi-natural habitats in Europe have been traditionally maintained by grazing or mowing, which halted successional changes and preserved biodiversity on a higher level. Since the 1950s the large-scale mechanisation of agriculture resulted in expansion of cropland and the abandonment of grasslands became an increasing issue in Europe. Recognizing the negative consequences of abandonment in the diversity of wildlife, habitat reconstruction interventions for mainly nature conservation purposes began in the 1980s to preserve the biodiversity of these semi-natural habitats.
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Comparison of vegetation of Hungarian Grey Cattle and Domestic water buffalo pastures in a sample area of the Danube-Tisza Interfluve
15-31Views:95We made a coenological study on the Kelemen-szék in the Kiskunság National Park. The coenological studies were carried out twice, in 2014 and 2015. During these two surveys, we examined in total 90 quadrats of mixed grazed and fenced control areas by domestic water buffalo and Hungarian Grey Cattle. Due to the size and heterogeneity of the studied area, we intended to investigate small homogeneous areas and respective control areas. Coenological surveys were done on lower and higher lying pastures, saline soil areas and loess areas.
The studied areas were assessed based on the Borhidi relative plant ecological indicators NB (relative nitrogen values) and WB (relative groundwater and soil moisture indicator values). The distribution of nature conservation value categories (TVK) and social behavior types (SzMT) were used to assess the areas. Cluster analysis and detrended correspondence analysis (DCA) were used to evaluate the data.
The data were assessed based on both habitat condition in terms of naturalness condition. On the other hand, relative ecological indicators of the occurred species. Our objectives were to provide a detailed description of the vegetation composition of the study areas, to assess the changes in grassland composition and their conservation impacts as a result of grazing and its abandonment, to assess the impact of grazing on the occurrence of protected species and weed species, and to assess grazing as a conservation habitat management practice.
The examination of the species composition showed that the loess and saline soil areas grazed by domestic water buffalos and Hungarian Grey Cattle provided a better composition of grassland in terms of natural condition compared to the control areas. In the dense and tall Puccinellia swards vegetation type, grazing requires more attention, because it is more vulnerable to grazing, has fewer species and is more damageable.
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Kaszálás felhagyás hatása helyreállított szikes és löszgyepek vegetációjára
21-29Views:86Grasslands recovered by sowing of low diversity seed mixtures are frequently managed by mowing. However only a few studies focused on the direct effects of post-restoration mowing on recovered grassland vegetation. In this study we followed vegetation changes in 13 recovered grasslands, in 5×5-m-sized exclosures with continuous and ceased mowing in Hortobágy, East-Hungary. We asked the following study questions:
(i) What are the effects of cessation of mowing on the vegetation structure of recovered grasslands?
(ii) What are the effects of cessation of mowing on the abundance of sown grasses, target and weed species?
(iii) Is yearly mowing an appropriate management for the maintenance of recovered grasslands?
Our results showed that the cessation of mowing caused litter accumulation, decrease in total cover and decrease in the cover of sown grasses compared to the continuously mown exclosures. The cover of perennial weeds was significantly higher in unmown exclosures compared to the mown ones. The species composition in mown exclosures remained more similar to reference grasslands than to the unmown ones. Our results suggest that without a regular post-restoration mowing the favourable stage of recovered grasslands can be rapidly vanished caused by litter accumulation and/or by the expansion of undesirable weedy species. We also stress that yearly mowing is solely enough to maintain grasslands recovered by low-diversity seed sowing, but cannot be considered to be enough to recover target vegetation composition.