Vol. 10 No. 1-2 (2012): Grassland Studies

Published September 12, 2012

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Cikk (Article)

  • Homoki gyepek spontán regenerációja kiskunsági parlagokon
    5-12
    Views:
    42

    Bár a spontán szekunder szukcessziós folyamatok vizsgálata kiemelt téma az ökológiában, mégis kevés publikáció vizsgálja a módszer alkalmazhatóságát a gyeprekonstrukcióban. Jelen vizsgálatban, kiskunsági homoki parlagokon gyepek spontán vegetációfejlődését tér-idő-helyettesítéses módszerrel vizsgálva az alábbi kérdésekre kerestük a választ:

            Hogyan változik a különböző funkcionális csoportok aránya a szukcesszió során?

            Milyen célfajok települnek be sikeresen a parlagokra?

            Megadható-e a spontán gyepregeneráció sebessége és értékelhető-e a sikeressége?

    A Kiskunságban összesen 12 homoki parlagot  vizsgáltunk. A parlagokat három korcsoportba soroltuk:

    10 év alatti (fiatal)

    10-20 éves (középkorú)

    20-40 éves (idős) parlagok.

    Korcsoportonként négy parlag növényzetét mértük fel. Referenciának három nyílt és három zárt homokpuszta gyepet választottunk. A növényfajok százalékos borításbecslését öt darab 2×2 m nagyságú kvadrátban végeztük egy kora májusi és késő júniusi időpontban, 2012-ben. Kimutattuk, hogy a szukcesszió folyamán az évelő lágyszárúak borítása növekedett, míg a rövidéletű fajok borítása csökkent. Az invazív fajok borítása szignifikánsan nagyobb volt a fiatal parlagokon, mint az idősebb korcsoportokban. A célfajok többsége már a fiatal és középkorú parlagokon is megtelepedett kisebb borításértékekkel, de szignifikánsan nagyobb borításuk az idősebb parlagokon volt. Megállapíthatjuk, hogy a kiskunsági homoki parlagok esetében viszonylag gyors és sikeres spontán gyepesedésre számíthatunk, a homoki gyepek fajkészlete már a szukcesszió első 10-20 évében regenerálódhat. Számos célfaj spontán betelepülése azonban még a rendelkezésre álló magforrások mellett is csak korlátozott. Ilyen esetben a célfajok megtelepedéséhez célzott propagulumbevitelre is szükség lehet. A spontán szukcesszió akkor lehet a legsikeresebb, amikor a célfajok már a szukcesszió első néhány évében megtelepednek a felhagyott szántókon. 

  • Kaszálás felhagyásának kezdeti hatása nyugat-magyarországi üde gyepek fajkompozíciójáradhdhdh
    13-20
    Views:
    53

    In 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. 

  • Kaszálás felhagyás hatása helyreállított szikes és löszgyepek vegetációjára
    21-29
    Views:
    68

    Grasslands 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. 

  • Tájhasználat és gyephasznosítás Natura 2000 területen: – esettanulmány a Balatonkeresztúri rétek példáján –
    31-38
    Views:
    71

    The aim of our study was to describe the actual land use of the Balatonkeresztúri rétek, a Natura 2000 site. We drew a map according to the land use categories. During field studies (in 2013) we recorded the actual land use activities and compared it with the officially registered land use categories. Our results showed that only 42.6% of the meadows and pastures are managed. All of the grasslands should be managed extensively to maintain the diversity of species. The area of grasslands could be extended with the increase of the number of livestock. We expect that the land use will change in a positive way as a result of agricultural supports. The ratio of managed (mowed and/or grazed) grasslands can increase in the future and as a consequence the diversity of grasslands can increase as well. 

  • Természetvédelmi élőhelykezelés hatása a gyöngyösi Sár-hegy gyepterületeinek vegetációjára
    39-48
    Views:
    73

    We studied the vegetation of grasslands on the Sár Mountain, in Gyöngyös. The areas are mowed regularly by the Bükk National Park and mechanical shrub control was done as well. The effects of these habitat management techniques were investigated on grasslands of different degradation levels. Coenological studies were made between May and June in 2013 with 2×2 m relevés. The study areas were characterised according to nature conservation value categories and life forms. Our results showed that the above mentioned management techniques had positive effects on the diversity of grasslands. On the managed grasslands the abundance of woody species decreased, while the abundance of annual and perennial grass species and dicotyledonous herbaceous species increased. The highest species number (58-78) was recorded in the case of control areas. The number of species was high (47-49) in the areas managed by mowing and mechanical shrub control. The lowest species number (43) was recorded in the areas which were not mowed after mechanical shrub control. According to the nature conservation value categories the number of protected species was the highest in the control areas. Our results approved that regular mowing is needed after mechanical shrub control to sustain the diversity of abandoned grasslands in the long run. 

  • Biomassza-fajgazdagság kapcsolatok vizsgálata szikes gyepekben és vizes élhelyeken
    57-61
    Views:
    35

    For an effective conservation and management in grasslands and wetlands it is essential to understand mechanisms sustaining biodiversity. Understanding biomass-species richness relationships is in the focus of recent scientific interest both from the agricultural and nature conservation point of view. We provided a detailed analysis of the relationship between major biomass components (total aboveground biomass and litter), and species richness along a long productivity gradient in grasslands and wetlands. We studied eight types of alkali and loess grasslands and five types of alkali wetlands in Hortobágy National Park, East-Hungary. We found that the relationship between total biomass and species richness can be described by humped-back curves both in grasslands and wetlands. was valid for the relation of total biomass and species richness. We detected the maximum of species richness at total biomass scores of 750 g/m2 in grasslands and at 2000 g/m2 in wetlands. Our results suggest that litter is one of the major factors controlling species richness in highly productive grasslands and wetlands. 

  • Összehasonlító botanikai és természetvédelmi vizsgálatok telepített és felújított gyepekben a Csákvár melletti Páskom területén
    63-73
    Views:
    44

    We studied the vegetation of a 260 ha gray cattle pasture near Páskom, which can be found in Zámoly basin. We carried out our surveyes in May 2012. The pasture can be divided into five parts. One part, approximately the half of the area (150.83 ha), is an oldfield grassland, which was overseeded 20 years ago. The other half of the pasture was restored (109.17 ha) in 4 different ways in 2009 and then was mowed until 2011. 7 relevés were made in each part of the pasture (the occurence of species and their cover scores were recorded). The aim of our study was to compare the effects of the different restoration methods and mowing on the botanical composition of the pasture. The results showed, that the grassland restored with hay transfer method was the most similar to the natural conditions. The greatest number of species was recorded in that part and the species of natural grasslands become dominant. The directly sowed and the spontaneous grassland parts separated chiefly from the semi-natural 30-year-old grassland. 

Szemle (Review)

  • Földalatti ökoszisztéma-mérnök fajok szerepe a gyepek fenntartásában
    49-55
    Views:
    90

    In this review we would like to analyze the effects of the subterranean rodents on vegetation using results from research of several taxons in different vegetation types and climate. Ecosystem engineers are organisms that modify, maintain, and create habitats. Subterranean rodents belong to this group. These species have an impact on the vegetation the microtopographical features of the soil and bulk density, they can change the structure, organic matter and moisture content of the soil they reduce the proportion of nitrogen. The fossorial rodents occur almost all over the world (expect Australia and Antarctica). These herbivorous species burrow tunnels under the ground and with this they have an impact on the floral diversity and dominance relations, the structure and composition of the association, the amount of biomass production as well as the distribution of plants and seeds. They can take effect directly with consumption of plants and indirectly with affect the plant-soil relations. At the basis of the results the activity of the subterranean rodents enhanced the diversity in most of the cases (of course there were also negative results and some researcher didn't find any differences between the mounds and the plots with no mounds). Their effect on the biomass was usually negative but they changed the species composition of their habitat at all times.