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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. Source


Lengyel A.,Institute of Ecology and Botany | Podani J.,Eotvos Lorand 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. Source


Nascimbene J.,University of Trieste | Marini L.,University of Padua | Marini L.,Swedish University of Agricultural Sciences | Odor P.,Institute of Ecology and Botany
Plant Ecology and Diversity | Year: 2012

Background: Few studies analysing lichen diversity have simultaneously considered interactions among drivers that operate at different spatial and temporal scales.Aims: The aims of this study were to evaluate the relative importance of host tree, and local, landscape and historical factors in explaining lichen diversity in managed temperate forests, and to test the potential interactions among factors acting at different spatial scales.Methods: Thirty-five stands were selected in the O{double acute}rség region of western Hungary. Linear models and multi-model inference within an information-theory framework were used to evaluate the role of different variables on lichen species richness.Results: Drivers at multiple spatial scales contributed to shaping lichen species richness both at the tree and plot levels. Tree-level species richness was related to both tree- and plot-level factors. With increasing relative diffuse light lichen species richness increased; this effect was stronger on the higher than on the lower part of the trunks. At the plot scale, species richness was affected by local drivers. Landscape and historical factors had no, or only a marginal, effect.Conclusions: Lichen conservation in temperate managed forests could be improved if the complex interactions among host tree quality and availability, micro-climatic conditions, and management were taken into consideration. © 2012 Copyright Taylor and Francis Group, LLC. Source


Odor P.,Institute of Ecology and Botany | Kiraly I.,Eotvos Lorand University | Tinya F.,Eotvos Lorand 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. Source


Kiraly I.,Eotvos Lorand 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. Source

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