Standovar T.,Eötvös Loránd University |
Horvath S.,Eötvös Loránd University |
Aszalos R.,Institute of Ecology and Botany
Nature Conservation | Year: 2017
The aim of this resurvey study is to check if herbaceous vegetation on the forest floor exhibits overall stability at the stand-scale in spite of intensive dynamics at the scale of individual plots and stand dynamic events (driven by natural fine scale canopy gap dynamics). In 1996, we sampled a 1.5 ha patch using 0.25 m2 plots placed along a 5 m × 5 m grid in the best remnant of central European montane beech woods in Hungary. All species in the herbaceous layer and their cover estimates were recorded. Five patches representing different stand developmental situations (SDS) were selected for resurvey. In 2013, 306 plots were resurveyed by using blocks of four 0.25 m2 plots to test the effects of imperfect relocation. We found very intensive fine-scale dynamics in the herbaceous layer with high species turnover and sharp changes in ground layer cover at the local-scale (< 1 m2). A decrease in species richness and herbaceous layer cover, as well as high species turnover, characterized the closing gaps. Colonization events and increasing species richness and herbaceous layer cover prevailed in the two newly created gaps. A pronounced decrease in the total cover, but low species turnover and survival of the majority of the closed forest specialists was detected by the resurvey at the stand-scale. The test aiming at assessing the effect of relocation showed a higher time effect than the effect of imprecise relocation. The very intensive fine-scale dynamics of the studied beech forest are profoundly determined by natural stand dynamics. Extinction and colonisation episodes even out at the stand-scale, implying an overall compositional stability of the herbaceous vegetation at the given spatial and temporal scale. We argue that fine-scale gap dynamics, driven by natural processes or applied as a management method, can warrant the survival of many closed forest specialist species in the long-run. Nomenclature: Flora Europaea (Tutin et al. 2010) for vascular plants; Soó 1968-1980 for syntaxa.
Odor P.,Institute of Ecology and Botany |
Kiraly I.,Eötvös Loránd University |
Tinya F.,Eötvös Loránd University |
Nascimbene J.,University of Trieste
Forest Ecology and Management | Year: 2013
Epiphytic bryophytes and lichens are an important component of the endangered forest biota in temperate forests, their diversity and composition patterns being regulated by tree, stand and landscape scale factors. The aim of this study is to improve ecological understanding of such factors in managed coniferous-deciduous mixed forests of Hungary in the context of forest management. In particular, this study investigate the effect of tree species composition, stand structure (tree size distribution, shrub layer and dead wood), microclimate (light, temperature and air humidity), landscape and historical factors on the stand level and tree level composition of epiphytic bryophytes and lichens. The relationships were explored by multivariate methods (redundancy analysis, canonical correspondence analysis and variation partitioning) and indicator species analysis. Tree species is among the most important driver of species composition in both organism groups. For bryophytes, the continuity of forest microclimate and the presence of shrub layer are also important, while lichen assemblages are influenced by light availability. Landscape and historical variables were less influential than stand scale factors. On the basis of our results, the main strategy of management focusing on epiphyte diversity conservation should include: (1) the maintenance of tree species diversity in mixed stands; (2) increasing the proportion of deciduous trees (mainly oaks and hornbeam); (3) the maintenance of large trees within the stands; (4) the presence of shrub and regeneration layer; (5) the creation of heterogeneous light conditions. © 2013 Elsevier B.V.
Heilmann-Clausen J.,Copenhagen University |
Aude E.,HabitatVision A S |
van Dort K.,Forestfun |
Christensen M.,Morten Christensen Consult |
And 5 more authors.
Journal of Biogeography | Year: 2014
Aim: Fungi are drivers of wood decay in forested ecosystem, while bryophytes use dead wood as a platform for their autotrophic lifestyle. We tested the hypothesis that fungal communities on beech logs are mainly structured by substrate quality, while bryophyte communities are structured by climatic gradients. In addition, we tested whether community structure in both organism groups is altered along a gradient from nearly pristine forest to forests heavily affected by management and human disturbance in the past. Location: Europe. Methods: We surveyed 1207 fallen beech logs in 26 of the best-preserved forest stands across six European countries, representing a gradient in overall naturalness of the forest landscape. Recorded species were classified into ecological guilds. Indirect ordination and variation partitioning was used to analyse the relationship between species composition and environmental variables, recorded at log or site level. Results: In total, 10,367 bryophyte and 15,575 fungal records were made, representing 157 and 272 species, respectively. Fungal communities were more clearly structured by substrate quality than were bryophyte communities. In both groups a distinct turnover in species composition was evident along a longitudinal gradient from Central to Western Europe. Fungi specialized in trunk rot and specialized epixylic bryophytes were scarcely represented in Atlantic regions, and partly replaced by species belonging to less specialized guilds. Variables related to climate and forest conditions were confounded along this main geographical gradient in community composition. Main conclusions: We found that bryophyte and fungal communities co-occurring on fallen beech logs in European beech forest reserves differed in their responses to biogeographical drivers and local-scale habitat filters. Both groups responded to major gradients in climate and forest conditions, but the loss of specialist guilds in degraded forest landscapes points to a functionally important effect of forest landscape degradation at the European continental scale. © 2014 John Wiley & Sons Ltd.
Kiraly I.,Eötvös Loránd University |
Nascimbene J.,University of Trieste |
Tinya F.,Koztarsasag u. 1 B |
Odor P.,Institute of Ecology and Botany
Biodiversity and Conservation | Year: 2013
The effect of management related factors on species richness of epiphytic bryophytes and lichens was studied in managed deciduous-coniferous mixed forests in Western-Hungary. At the stand level, the potential explanatory variables were tree species composition, stand structure, microclimate and light conditions, landscape and historical variables; while at tree level host tree species, tree size and light were studied. Species richness of the two epiphyte groups was positively correlated. Both for lichen and bryophyte plot level richness, the composition and diversity of tree species and the abundance of shrub layer were the most influential positive factors. Besides, for bryophytes the presence of large trees, while for lichens amount and heterogeneity of light were important. Tree level richness was mainly determined by host tree species for both groups. For bryophytes oaks, while for lichens oaks and hornbeam turned out the most favourable hosts. Tree size generally increased tree level species richness, except on pine for bryophytes and on hornbeam for lichens. The key variables for epiphytic diversity of the region were directly influenced by recent forest management; historical and landscape variables were not influential. Forest management oriented to the conservation of epiphytes should focus on: (i) the maintenance of tree species diversity in mixed stands; (ii) increment the proportion of deciduous trees (mainly oaks); (iii) conserving large trees within the stands; (iv) providing the presence of shrub and regeneration layer; (v) creating heterogeneous light conditions. For these purposes tree selection and selective cutting management seem more appropriate than shelterwood system. © 2012 Springer Science+Business Media Dordrecht.
Baldi A.,Hungarian Academy of Sciences |
Baldi A.,Institute of Ecology and Botany |
Batary P.,University of Gottingen |
Batary P.,MTA ELTE MTM Ecology Research Group |
Kleijn D.,Wageningen University
Agriculture, Ecosystems and Environment | Year: 2013
Agricultural intensification is a major threat to biodiversity. Agri-environment schemes, the main tools to counteract negative impacts of agriculture on the environment, are having mixed effects on biodiversity. One reason for this may be the limited number of species (groups) covered by most studies. Here, we compared species richness and abundance of 10 different species groups on extensively (0.5 cattle/ha) and intensively (1.0-1.2 cattle/ha) grazed semi-natural pastures in 42 fields in three Hungarian regions. Plants, birds and arthropods (leafhoppers, true bugs, orthopterans, leaf-beetles, weevils, bees, carabids, spiders) were sampled. We recorded 347 plant species, 748 territories of 43 bird species, and 51,883 individuals of 808 arthropod species. Compared to West European farmlands, species richness was generally very high. Grazing intensity had minor effects on α and β diversity, abundance and composition of the species assemblages. Region had significant effects on species richness and abundance of four taxa, and had strong effects on β diversity and species composition of all taxa. Regional differences therefore contributed significantly to the high overall biodiversity. We conclude that both grazing regimes deliver significant biodiversity benefits. Agri-environmental policy at the EU level should promote the maintenance of large scale extensive farming systems. At the national level, the effectiveness of agri-environment schemes should be improved via promoting and using research evidence. © 2012 Elsevier B.V.
Lengyel A.,Institute of Ecology and Botany |
Podani J.,Eötvös Loránd University |
Podani J.,Hungarian Academy of Sciences
Journal of Vegetation Science | Year: 2015
Questions: What is the relative importance of our methodological decisions concerning sampling (plot size) and data analysis (data transformation, resemblance coefficient, hierarchical clustering strategy and number of clusters) in vegetation classification? Are there differences between the conclusions when the full range or only a more practical narrow range of methodological choices is tested? What is the difference between results for actual and random data? Location: Rock grassland in Hungary. Methods: The full procedure of vegetation classification was simulated using actual and random data. Variation in classification results was partitioned using distance-based redundancy analysis. The RDA models were subjected to variation partitioning to determine the relative importance of methodological decisions. Results: RDA models explained more variation in classifications of random than in real data. Classification algorithm, cluster level, data transformation and mean plot size were always included among the most significant variables, however, the other variables also had a considerable effect in certain situations. Conclusions: As adjusted R2 values suggest, the overall effect of methodological decisions on classifications is larger for randomly structured than actual data, due possibly to a stronger clustering tendency in the latter. The clustering algorithm, cluster level, data transformation and plot size should be chosen most carefully before classification analyses, but any of the examined decisions can significantly affect the result. In addition to the mean, the range of plot sizes should also be carefully delimited during relevé selection for classification studies. The main decision about the classification algorithm is whether a chain-forming or group-forming method is used. The data transformation had a more significant effect on real data than on simulations with random variation, thus supporting the ability of the application of different abundance scales in revealing different facets of biologically relevant patterns in community composition. The resemblance measure had a relatively weak effect, suggesting that it is not as influential as previously thought. © 2015 International Association for Vegetation Science.
Pinke G.,University of West Hungary |
Karacsony P.,University of West Hungary |
Botta-Dukat Z.,Institute of Ecology and Botany |
Czucz B.,Institute of Ecology and Botany
Journal of Pest Science | Year: 2013
The weed control of sunflower is a great challenge for farmers throughout the World. In Hungary, one of the greatest concerns is the pernicious weed Ambrosia artemisiifolia, which produces allergenic pollen. The main goal of this study was to identify cultural, weed-management and environmental factors determining weed species composition and the abundance of A. artemisiifolia in sunflower fields. Altogether 49 sunflower fields across Hungary were surveyed for their weed flora, and 30 environmental, cultural and weed-management factors were measured. Using a minimal adequate model containing 14 terms, 38 % of the total variation in species data could be explained. Soil Mg and Ca content, preceding crop, temperature, and field size had significant effects on species composition. Most of the herbicides were effective against annual grass species, but no herbicide was universally effective against broad-leaved weeds. Almost all types of weeds were efficiently reduced with mechanical weed control. A relatively high share of the explanatory variables were environmental factors, suggesting that the success of weed management in sunflower fields strongly depends on a complex of edaphic and climatic constraints. The abundance of Ambrosia artemisiifolia was positively correlated with high soil Ca content, lower temperature, the preceding crop being a cereal, and smaller field sizes; while considering herbicides it seemed to be most sensitive to fluorchloridon and propisochlor application. To reduce noxious broad-leaved weed species could require specific herbicide mixtures, and mechanical weed control should also be integrated into weed management. © 2013 Springer-Verlag Berlin Heidelberg.
Adam R.,Institute of Ecology and Botany |
Odor P.,Institute of Ecology and Botany |
Boloni J.,Institute of Ecology and Botany
Community Ecology | Year: 2013
Different types of forest use significantly changed the structure and species composition of European temperate forests. Herbaceous species and seedlings are important parts of the forest ecosystem, thus it is necessary to understand the effects of stand characteristics on the species composition of the understory. In our study we assessed the main factors that affect the species composition of herb and tree seedling assemblages in Quercus petraea and Q. cerris dominated stands (age 50-150 years) in the Bükk Mountains, Hungary. The relationship between the studied assemblages and explanatory variables (tree species composition, stand structure, canopy closure and topography) were explored by Redundancy Analysis (RDA). The occurrence of herbaceous species was affected by canopy closure, stand structure (mean DBH and DBHcv of trees), topography and the density and diversity of shrub layers. Oak forest species were associated with more open stands with sparsely distributed large trees, while mesic forest species were positively associated with heterogeneous stand structure, low shrub density, and western exposure. Seedlings of trees and shrubs showed a dispersal limited phenomenon. The composition of seedlings was significantly influenced by the mean DBH of trees, the structural heterogeneity of the overstory, the tree species diversity and the density of shrub layers. However the seedlings of both dominant oak species required the same stand structure, sessile oak was able to regenerate almost exclusively in those stands where it was dominant in the overstory, which is significant for the management of the species. Generally, forest management affects species composition and structure of the overstory, accordingly it had direct and indirect effects on the understory community as well.
Botta-Dukat Z.,Institute of Ecology and Botany
Acta Botanica Hungarica | Year: 2016
This study was motivated by the fact that although the plasticity of its above-ground organs is obvious in natural conditions and there are many data on the plasticity of Solidago's rhizome system in glasshouse experiments, there are no data on below-ground plasticity under natural conditions. We compared the morphology of rhizomes in two, contrasting habitats. We found that rhizome system responded to environmental conditions: in the dry habitat, ramets developed more but shorter rhizomes compared to the wet habitat. The decrease in rhizome length can be explained by the decrease in the size of above-ground organs, but the increase of rhizome number cannot. The most important regulating factor of rhizome growth is probably its mechanical restriction by the root biomass of other species. © 2016 Akadémiai Kiadó, Budapest.
Kovacs-Hostyanszki A.,Institute of Ecology and Botany |
Baldi A.,Institute of Ecology and Botany
Biological Conservation | Year: 2012
Economic pressures from increased commodity prices and the growing demand for land for biomass plantations led to the abolition of compulsory set-aside fields in the European Union in 2008, affecting ca. 10% of total agricultural area. This area is now managed more intensively, and this is expected to adversely affect farmland biodiversity. Unfortunately, no mitigation of set-aside loss was introduced. Here we examined, whether or not set-aside fields managed in voluntary agri-environment schemes have the potential to improve farmland bird populations, as indicators of farmland biodiversity. We chose one, two and three year-old set-aside fields sown by a grass-legume mixture when established and selected winter cereal fields and semi-natural grasslands in Hungary as control sites. Relative abundance of birds was assessed; species were assigned to feeding guilds and classified according to their European conservation status. Species richness of herbaceous plants, cover of bare ground and vegetation height were used as covariates. Set-aside fields had higher species richness and abundance of birds compared to the adjacent winter cereal fields, similar to semi-natural grasslands. We found a positive correlation between set-aside age and farmland bird species richness and abundance. This can be explained mainly by the altered vegetation, especially the shorter vegetation height from the second year in the set-aside fields. We found no difference in the distribution pattern of species richness and abundance between feeding guilds according to set-aside age and habitat types. The wide scale application of voluntary set-aside management in agri-environment programs therefore has a high potential to mitigate the negative effects from the loss of compulsory set-aside schemes, and thus need the allocation of considerable resources in the forthcoming reformed CAP. © 2012 Elsevier Ltd.