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Biomassza-fajgazdagság kapcsolatok vizsgálata szikes gyepekben és vizes élőhelyeken
57-61Views:43For 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.
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Az avar rövid életű keresztesvirágú (Brassicaceae) gyomfajok csírázásra gyakorolt hatása
3-8Views:42Recruitment by seeds is essential both in vegetation dynamics and in supporting grassland biodiversity. Recruitment by seeds is feasible in suitable microsites from the seed rain and/or by establishment from persistent soil seed banks. Cessation of grassland management by grazing or mowing results in litter accumulation, which leads to the decrease of species richness by the decreased availability of open patches. Low amounts of litter are often beneficial, while high amounts of litter are detrimental for seed germination and seedling establishment of short-lived species. However, the magnitude of these effects on germination and seedling establishment in relation to litter and seed attributes are scarcely studied. This motivated us to design an indoor experiment to explore the effects of litter on seedling establishment. We germinated six short-lived Brassicaceae species (Arabidopsis thaliana, Capsella bursa-pastoris, Descurainia sophia, Erophila verna, Lepidium campestre, and Lepidium perfoliatum) with different seed mass under increasing litter cover. We found that both seed mass and litter had significant effect on germination and establishment of the sown species. Small-seeded species were significantly negatively affected by the 300 g/m2 and/or 600 g/m2 litter layers. No negative litter effect was detected for species with high seed masses (Lepidium spp.). No overall significant positive litter effect was found, although for most of the species; total seedling numbers was not the highest at the “bare soil” pots. Our results suggest that the effects of litter accumulation on the germination and establishment of short-lived species are less feasible in case of large-seeded species than on small-seeded ones.
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Long-term mowing on biomass composition in Pannonian dry grasslands in the Western-Cserhát
35-38Views:60This study is focusing on the vegetation of seminatural dry grasslands. Those loess grasslands are valuable with large biodiversity; however their long-term preservation requires regular conservation management. The report demonstrates the results of mowing experiment, designed to suppress the spread of unpalatable grass species, Calamagrostis epigeios. The study site is located in mid-successional loss grasslands, in the Western-Cserhát, near Rád, northern Hungary.
The study aims to the investigate the followings: Can the unpalatable Calamagrostis epigejos be suppressed by mowing? Are there possibilities to increase the diversity of sward by this? The study aims, to measure potential value-increasing effect of mowing, and to determine the carrying capacity in the aspect of grassland management.
In 2001, Camagrostis epigeios was the species with the highest coverage rate according to the both treatment types, with an average cover value of 63%. However, as a result of mowing, a significant difference was detected in the amount of litter and legumes species as well. The number of species showed a slight increase in both types of treatment, from 15 to 37 in the mowed plots, but also from 18 to 27 in the control plots. We concluded that mowing twice a year was beneficial to modify botanical composition of a grassland. In a way it was suited well for agricultural usage, in particular grazing which can replace the expensive and time-consuming scythe. It is also a suitable management measure for controlling the native invader species as a Calamagrostis epigeios, and can significantly increase the proportion of species with higher forage values.
Mowing has significantly increased the density of Calamagrostis epigeios, the species richness, and the diversity in the course of secondary succession. Therefore, mowing twice a year proved to be a successful management measure for controlling Calamagrostis epigeios, and for obtaining a sward composition. The treatment was effective in restoring grassland composition, although the achievement and maintenance of favourable conservation status for the grassland habitat require long-term management planning and regular treatment. According to the objectives, mowing not only promotes the control of the invasive species, but also the economic utilization of the area.
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Monthly changes in the production and content values of wet Hungarian gray cattle pasture and the relationship with species richness
19-28Views:119Grassland management tests were performed on different grazing loaded gray cattle pasture and hayland areas 4 times (April, May, June, September) during the grazing season in Tapolca-basin. 5-5 pieces of 2×2 m samples were examined on each sample area, prepared according to the Braun-Blanquet method (1964) in April, May, June and September and with this, we also measured the amount of biomass and its content.
Based on results additional pasture had the largest gazing livestock carrying capacity but it had the weakest feed quality as well. During grazing season due to ongoing livestock grazing, species composition has changed the most in case of pasture and the number of species was the greatest here as well. Proportion of grasses declined in parallel with the amount of legumes, which grown till late summer.
Nutrient content of pasture forage was the most appropriate because of high crude protein and less crude fiber content. Grazing for 34 days/year was not enough in case of additional pasture where Festuca arundinacea had the largest coverage. This is reflected in low number of species richness and small nutritional values of sample areas. For sedge rich low-lying areas mowing utilization is the most effective. -
Botanical and natural conservation comparison of seminatural and man-made grasslands in Paskom near Csakvar
3-14Views:310During the survey, the vegetation, botanical composition and grassland management values of a grassland were studied. The study site was originally a pasture, then was transformed into an arable land and finally back to pasture. The 160-ha-sized area is called „Szűzföld” and is located in the Zámoly Basin, West Hungary. In 1998, grazing of Hungarian grey cattle has begun on the grassland. The changes in the vegetation were followed from 1998, making records in every 6th year (1998, 2015, 2021). 6 coenological records were made in each type of grasslands, by recording the list of the occurring taxa and their cover values. During the survey the main questions were the following: considering nature conservation, coenology and grassland management, in which direction does the vegetation evolve with the grazing? Was the grazing with Hungarian grey cattle successful?
Based on the results, the grasslands became much more mosaic-like; drier and wetter vegetation patches could be separated (2015, 2021). As the grazing continued, species richness and diversity increased, especially in the wet areas.
The number and the cover of economically important grass taxa and legumes have increased. The following taxa became dominant: Festuca pseudovina in the drier parts, Agrostis tenuis and A. stolonifera in the wet ones. Based on the life form system of Pignatti, the area is not overgrazed, as rosette and reptant taxa did not became dominant. Based on nature conservation values, cover of the taxa of natural grasslands increased.
During the grazing, the meadow was universally covered mainly by weeds in 1998, and became much more valuable by 23 years later by means of nature conversation and grassland management. Moreover, this state has been stabilized according to the diversity values.
Based on the results, the grazing with Hungarian grey cattle was successful by both nature conservational and economical means. -
Recovery of grasslands in former croplands using the combination of seed sowing and hay transfer
5-11Views:58In accordance with general trends in agricultural and natureőconservation practice in Europe, grassland restoration and traditional grassland management has gained increased importance in Hungary. In grassland restoration using of low rates of seed (less than 30kg/ha) and hay cover is suggested. In the present paper the effect of hay cover combined with low rate of seed (25 kg/ha) is studied in early grassland recovery. We aimed at to answer the question whether or not the speed of grassland recovery can be increased with a combined use of seed sowing and hay cover. The establishment of Festuca species was favoured by hay cover combined whit seed sowing. The emergence of shortlived weeds was significantly lower on most of the fields treated with hay cover and seed sowing. The species richness and diversity of early weeds did not differ significantly in fields sown only and fields treated both with seed sowing and hay cover. Our results suggest that the combination of seed sowing and hay cover is successful in fields, where high rate of weed invasion is possible, thus intensive post-restoration management is necessary.