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Investigations on grassland and nature reservation effect of horse grazing in Tapolca and Káli Basins (2008)
65-72Views:159Examined areas can be found in the Tapolca and Káli Basins near Köveskál and Nemesgulács. Near Köveskál 2 horses were grazed on a 1 ha grassland, which was on a degraded association of Cynodonti-Poëtum angustifoliae. Control area was found close to the grazed grassland where Salvinio-Festucetum rupicolae association was found. The grassland was grazed formerly by sheep. Near Nemesgulács 4 horses were grazed on a 6 ha pasture under free range grazing system (0.7 horse/ha) on a Cynodonti- Poëtum angustifoliae grassland that is situated on a slope. Sample areas were selected the upper (UTS) and lower (LTS) third of the slope. This area formerly was as vineyard. 5-5 replicates of 2 by 2 m coenological quadrates were monitored on each sample area. Sward composition was investigated by Braun-Blanquet method (1964) in the grazing season of 2008. Ground cover (D) species composition and species number (n) were evaluated as analytical parameters. Relative nitrogen demand (NB), social behavior types (SBT) (Borhidi, 1995) and nature conservation value categories (TVK) (Simon, 2000) were also analyzed. At the LTS of the slope near Nemesgulács we could find species with bigger proportions indicating nutrient rich production sites and N indicating Artemisia vulgaris, characteristic species of manured sites appeared, too. At the UTS their proportion was smaller. The reason for this difference is the nutrient run off the slope and its accumulation at the LTS. The reason for the low nutritive value of the grassland are the lack of valuable Poaceae and pulses species and the low total cover. Valuable plant species were grazed out of the sward and negative effects of trampling could have been observed. Concerning the selective grazing preference of horses, the species composition of this area is not suitable for horse grazing. Instead of horses the area could be more suitable for sheep grazing. Pasture near Köveskál had extremely high proportion of species requiring nutrient rich conditions that can be probably due to frequent depositions of excreta and urine by grazing horses. Both control and pasture areas has the highest (approx. 35% absolute) cover of natural species with disturbance tolerance. The biggest difference in nature conservation value categories was the decrease of association composing species on the pasture. This was mainly caused by the grazing out of Poa angustifolia that was the most valuable species in the association. Overgrazing and grazing method applied caused very low plant cover on the grazed pasture.
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Fajösszetétel és diverzitás változás kiskunsági száraz és nedves fekvésű legelőkön
15-30Views:193Investigations were carried out in wet – next to Tatárszentgyörgy, and dry grass pasture – next to Bugac, both located in Kiskunság, in the central region of Carpathian Basin. Recordings were taken every June of 2007, 2008, 2009 and 2010 from Tatárszentgyörgy – where cattle were grazed, and 1997, 2005 and 2010 from Bugac, where cattle and sheep were grazed. Coenological recordings were taken in three zones. The first zone ("A" zone) located 0-50 m near the stable, second zone ("B" zone) located 50-150 m from the stable, while the third zone ("C" zone) located farther then 150m from the stable. Analyses of ecological and environmental factors were based on Borhidi’s relative ecological indicators. Life form analyses were performed by Pignatti life form types. For statistical evaluation, R software was applied. Shannon diversity. Based on our results for both dry and wet grasslands, quadrates of "A" zone were well isolated from the rest of the zones. Overgrazing, which involves considerable trampling, vanishes differences among vegetations, thereby promotes weed and disturbance tolerant rich vegetation. The lowest species number and diversity could be found here. Recordings for "B" and "C" zones separated from recordings of "A" zone, furthermore, quadrates of wet and dry grasslands formed separate groups. From recordings of "B" and "C", zone perennial grass species (H caesp) and the emerging perennial (H wrap) species multiplied and these species were the indicators of grazing. The greatest lifeform richment were presented among "B" zone recordings. The amount of intensive grazing indicator species, such as creeping perennials (Hrep) was significant in "B" zone recordings of Tatárszentgyörgy. Grazing stabilised the local vegetation, but increased the ratio of disturbance tolerant species, which was confirmed by conservation evaluation. This is due to the conversion of grassland types, the transition from free grazing to switch grazing, which resulted in an intensive involvement of the more distant "C" zone as well. "A" zones fully converted; they changed into fully reliefs. Further located sample area vegetations were not homogenised by grazing and even helped the preservation of characteristic species. In the aspect of environmental protection, vigorous grazing led to a more valuable vegetation in "B" zone in an arid grassland (Bugac). According to the sample area, wet grasslands from the sandy areas of Kiskunság, preserve nature protection values and grass composition better moving away from stables, due to less grazing pressure. Drier backgrounds tolerate stronger grazing pressure (Bugac), while in case of wetter areas (Tatárszentgyörgy) – considering sustainability – grazing should be carried out with caution.