A következő címkéjű bejegyzések mutatása: Abandonment. Összes bejegyzés megjelenítése
A következő címkéjű bejegyzések mutatása: Abandonment. Összes bejegyzés megjelenítése

2014. január 28., kedd

Kelemen et al. (2014) Biodiversity and Conservation

András Kelemen, Péter Török, Orsolya Valkó, Balázs Deák, Tamás Miglécz, Katalin Tóth, Tamás Ölvedi & Béla Tóthmérész (2014): Sustaining recovered grasslands is not likely without proper management: vegetation changes after cessation of mowing. Biodiversity and Conservation, in press. DOI: 10.1007/s10531-014-0631-8


Abstract
Grasslands recovered by sowing low diversity seed mixtures of local provenance are usually managed by mowing. Besides restoration success only a few studies have focused on the direct effects of post-restoration mowing on recovered grassland vegetation. In this study we followed vegetation changes in 13 successfully recovered grasslands in 5 × 5-m-sized sites with continuous and ceased mowing at Hortobágy National Park, East-Hungary. We asked the following questions: (i) What are the effects of cessation of mowing on the vegetation structure and diversity of recovered grasslands? (ii) What are the effects of cessation of mowing on the abundance of sown grasses, target and undesirable species? (iii) Is yearly mowing an appropriate management tool for the maintenance of recovered grasslands? Our results showed that the cessation of mowing caused litter accumulation, while diversity, total vegetation cover and the cover of sown grasses decreased compared to the mown sites. The cover of undesirable perennial species was significantly higher in unmown sites than in mown ones. The species composition of mown sites remained more similar to near-natural grasslands than the unmown ones. Our results suggest that without regular post-restoration mowing the favourable status of recovered grasslands can rapidly decline due to litter accumulation and by the expansion of undesirable species, even in the short-run. We also stress that while yearly mowing is enough to maintain grasslands recovered by low-diversity seed sowing, it cannot be considered to be enough to recover target vegetation composition.


Keywords
Grassland restoration, Seed sowing, Abandonment, Post-restoration management, Biodiversity, Cirsium arvense

2013. december 18., szerda

Albert et al. (2014) Applied Vegetation Science

Ágnes-Júlia Albert, András Kelemen, Orsolya Valkó, Tamás Miglécz, Anikó Csecserits, Tamás Rédei, Balázs Deák, Béla Tóthmérész & Péter Török (2014): Secondary succession in sandy old-fields: a promising example of spontaneous grassland recovery. Applied Vegetation Science, DOI: 10.1111/avsc.12068, PDF itt

Abstract
Question: Based on the spontaneous vegetation development of old-fields in the Nyírség and Kiskunság sand regions (Hungary), we aimed to answer the following questions using the chronosequencemethod: (1) how do the proportions of different functional groups change during succession; (2) which target species establish successfully in the old-fields during the course of succession; and (3) how successful is spontaneous succession in the recovery of target grasslands?
Location: Two sand regions of the Great Hungarian Plain: (1) the Nyírség sand region (East Hungary, acidic sand, moderately continental climate) and the Kiskunság (Central Hungary, calcareous sand, continental climate).
Methods: Altogether 24 old-fieldswere classified into young (<10-yr-old),middle-aged (10–20-yr-old) and late-succession (20–40-yr-old) old-fields; four fields in each age category. For baseline vegetation reference, three open and three closed sand grassland stands in both regions were sampled in the vicinity of the old-fields. The percentage cover of vascular plants was recorded in five 2 9 2-m plots in each field, in early May and late June 2012. We used life forms, clonal spreading traits and Ellenberg indicator values for nutrients in the analysis. Species of Festuco-Brometea class were considered as target species.
Results: The cover of hemicryptophytes and geophytes increased, the cover of short-lived species decreased with time. Cover of species without clonal spreading ability decreased, while cover of species with clonal spreading ability increased with increasing field age. The cover of invasive species decreased with increasing field age. The majority of target species had established already in the young and middle-aged old-fields, although their cover was significantly higher in the two older age groups.
Conclusion: Spontaneous succession can be a vital option in recovery of sand grassland vegetation in Central Europe; the majority of the species pool of sandy grasslands can be recovered in the first 10–20 yrs. However, the success of grassland recovery can be strongly influenced by the surrounding species pool and can be slowif seed dispersal is limited. Spontaneous succession ismost promising when the target species of grasslands immigrate at the very beginning of the succession, within the first few years.


Keywords
abandonment, acidic sand, calcareous sand, clonal traits, grassland restoration, invasion, spontaneous succession

2013. szeptember 25., szerda

Habel et al. (2013) Biodiversity and Conservation

Jan Christian Habel, Jürgen Dengler, Monika Janišová, Péter Török, Camilla Wellstein, Michal Wiezik (2013) European grassland ecosystems: threatened hotspots of biodiversity.Biological Conservation 22(10): 2131-2138.


Abstract
Biodiversity is not homogenously distributed over the globe, and ecosystems differ strongly in the number of species they provide. With this special issue we highlight the ecology and endangerment of one of the most diverse ecosystem of Europe: the European grassland ecosystems. The selected 16 contributions describe interactions from below-ground to the atmosphere and focus on (1) effects of abiotic and biotic on species diversity, (2) the impact of various factors along spatial and temporal gradients, (3) the relevance of falling abandoned and eutrophication—including countervailing management strategies like encroachment; and (4) intraspecific effects based on physiology, genetics and intraspecific plasticity. The contributions cover fungi, plants, and invertebrates and highlight effects taking place at the level of ecosystem, species community, species, populations, and also within individuals (physiology and genetics).


Keywords
Abandonment, Animal assemblage, Conservation management, Diversity hotspot, Eutrophication, Plant community, Species richness