Authors:Enikő Vida, Orsolya Valkó, A. Kelemen, P. Török, B. Deák, T. Miglécz, Sz. Lengyel, and B. Tóthmérész
We studied the early vegetation dynamics in former croplands (sunflower and cereal fields) sown with a low-diversity seed mixture (composed of 2 native grass species) in Egyek-Pusztakócs, Hortobágy National Park, East-Hungary. The percentage cover of vascular plants was recorded in 4 permanent plots per field on 7 restored fields between 2006 and 2009. Ten aboveground biomass samples per field were also collected in June in each year. We addressed two questions: (i) How do seed sowing and annual mowing affect the species richness, biomass and cover of weeds? (ii) How fast does the cover of sown grasses develop after seed sowing? Weedy species were characteristic in the first year after sowing. In the second and third year their cover and species richness decreased. From the second year onwards the cover of perennial grasses increased. Spontaneously immigrating species characteristic to the reference grasslands were also detected with low cover scores. Short-lived weeds were suppressed as their cover and biomass significantly decreased during the study. The amount of litter and sown grass biomass increased progressively. However, perennial weed cover, especially the cover of Cirsium arvense increased substantially. Our results suggest that grassland vegetation can be recovered by sowing low diversity mixtures followed up by yearly mowing. Suppression of perennial weed cover needs more frequent mowing (multiple times a year) or grazing.
The acceleration of grassland loss on the global scale has been reported in many studies, which is often attributed to the combination of land use change and increased variability of climatic processes. Extensive steppe national parks serve as an ideal study site for grassland conservation, especially wilderness areas where the natural effects of grazing on wildlife can still be tracked. In our study we aim to investigate the effects of habitat structure, grazing type and intensity as well as climatic variables on species abundance, species richness and abundance of functional groups of ground-breeding bird species in the largest compact alkali grassland area of central Europe. We applied the information theoretic approach estimating the importance of ecological predictors according models of substantial support. The main result of our study shows that ground-breeding bird communities in steppe areas exhibit highly species-specific responses to the species of grazers, grazing intensity, habitat composition and climatic predictors. Across the most supported models, species-specific habitat composition values were the most supported predictors. Our findings show that although the response of ground-breeding birds to vegetation, grazing and climatic predictors is highly species-specific, consistent patterns of responsiveness to grazing and climatic patterns emerge, which calls for long-term studies on the combined effects of climatic variability and management of grazing systems.
Authors:R. Kiss, J. Sonkoly, P. Török, B. Tóthmérész, B. Deák, K. Tóth, K. Lukács, L. Godó, A. Kelemen, T. Miglécz, Sz. Radócz, E. Tóth, N. Balogh, and O. Valkó
Kelemen , A. , Török , P. , Valkó , O. , Deák , B. , Tóth , K. and Tóthmérész , B. ( 2015 ): Both facilitation and limiting similarity shape the species coexistence in dry alkaligrasslands . – Ecol. Complexity 21 : 34 – 38 . https
viszönyai és szukcessziós kapcsolatai. (Phytocenology and successional relationships of alkaligrasslands in Hortobagy National Park.) Botanikai Közlemények 71:63-77.
A Hortobágyi Nemzeti Park sziki gyepeinek fitoconologiai
Molnár, A. and Kapocsi, J. (1997):
A füves területek típusainak jellemzése és kezelése. Szikes gyepek
. (Description and management of grassland habitats. Alkaligrasslands). — In: Kelemen, J. (ed.): Irányelvek a füves területek természetvédelmi