Search Results

You are looking at 1 - 9 of 9 items for

  • Author or Editor: J. Bölöni x
  • All content x
Clear All Modify Search

Due to the global land use and climate change, endangerment of natural vegetation is increasing. That is why the threatening factors were documented in details during the MÉTA mapping. We have documented the impacts of water management, land use (management of woodlands and grasslands), the invasive species, urbanisation, habitat fragmentation and the neighbourhood, as well. In the present article (1) we evaluate the actual state of the habitats by the 28 threat types documented during the MÉTA mapping; (2) we introduce 12 newly developed indicators, which were applied for the semi-quantitative comparison of the overall degree of endangerment of the Hungarian habitats.Based on the summarisation of our results the most seriously endangered habitats in Hungary are as follows: sand and loess steppe oak woodlands (M2, M4, L2x), tussock sedge communities (B4), extensive orchards (P7), closed lowland oak woodlands (L5, L6), water-fringing and fen tall herb communities (D5), wooded pastures (P45), vegetation of loess cliffs (I2), rich fens and Molinia meadows (D1, D2), Cynosurion grasslands and Nardus swards (E34), swamp woodlands (J2), xero-mesophilous grasslands (H4) and salt steppe oak woodlands (M3).The least endangered types are the rocky habitats (I4, LY3, H1, G2, M7), certain halophytic (F1a, F5, F1b, F2, B6) and aquatic habitats (A23, A3a, A1), open acidophilous woodlands (L4b), dry shrub vegetation with Crataegus and Prunus spinosa (P2b) and the beech woodlands (K5).

Restricted access
Restricted access

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.

Restricted access

Actual distribution maps of vegetation types are important data sources of basic and applied research, respectively. Though there were several attempts to map the actual vegetation of Hungary, the MÉTA program was the first to map all the (semi-)natural habitat types on the whole territory of Hungary. The paper discusses the woodland and shrubland habitats. 41 habitats are presented and discussed. The paper provides additional data on the area and distribution of the habitats mainly at the physical geographical macroregion scale.

Restricted access

Effective conservation of (semi-)natural habitats needs knowledge on the naturalness, the actual quality of a habitat or vegetation patch. Nevertheless, there are only a few studies have been published in this topic so far. During the MÉTA project, between 2002–2005, we have surveyed the semi-natural vegetation of Hungary and assessed the naturalness of the predefined 86 habitat types. In this paper we present the country scale analysis on the naturalness of these habitat types. We compared the naturalness of the individual habitat types and also habitat groups, as well as the naturalness of the physical macroregions of Hungary. Euhydrophyte habitats and habitats deserving high abiotic stress are the most natural ones, while secondary shrublands, uncharacteristic forests and grasslands are the less natural. For the forest habitats we compared and discussed the naturalness values given by the MÉTA mappers and the values gained in the TERMERD (assessing forest naturalness in Hungary) project. In case of regions, Kisalföld has the lowest naturalness, and surprisingly the quality of the Alföld and the Középhegység is nearly equal if we consider only the remained vegetation.

Restricted access

Regeneration potential is regarded as a kind of functional indicator, which is applied for the assessment of the habitat quality and a kind of nature conservation value. In this context “quality” does not refer to the actual state but possibilities for the future. During the MÉTA project, regeneration potential have been recorded on the scale of the quadrates (35 km 2 , 2,813 quadrates in Hungary), for each habitat of the quadrate (ignoring some featureless habitats). We have estimated three different kinds of regeneration potential: on spot, on the place of neighbours and on old-fields open water, bare rock. The categories used were: good regeneration ability, moderate, low, or there is no place for regeneration.Values of regeneration potential on spot are usually rather high. Habitats with the highest regeneration potential are the aquatic ones, shrub vegetation, halophytic vegetation, marshes, grasslands with woodland origin, sand poplar-juniper woodlands, and the poorest is the regeneration potential of the forest steppe woodlands. Lower are the values of the regeneration potential of each vegetation type on the place of the neighbours. Relatively easily spread onto the neighbouring vegetation patches the halophytic habitats, poplar-juniper woodlands, the secondary shrub vegetation, some aquatic habitats, certain riverine vegetation types and marshes. Moderate or lower is this value of this regeneration potential category for the xeric highland woodlands, rocky habitats, xeric and mesic lowland woodlands, grasslands with woodland origin and some fen vegetation types. In spite of the rather low values calculated for the whole country, the following habitats regenerate relatively well on old-fields, open water or rock surfaces, or in abandoned vineyards: the dry secondary shrub vegetation, poplar-juniper woodlands, Scots pine woodlands, halophytic habitats, some aquatic habitats and marshes. Most habitats regenerate poorly, for example, the zonal woodlands. Never or barely regenerate on old-fields: some fen habitats, the steppe oak woodlands, mesic lowland woodlands, some rock habitats, acidophilous woodlands, the zonal woodlands, the rock and sand coniferous woodlands.When comparing the values of regeneration potential on spot, on the place of the neighbours and on old-fields, most striking is the fact that the least habitats have moderate or high regeneration ability in case of the third kind of regeneration potential, and regeneration ability on adjacent vegetation patch represent a transitional state from this aspect. Some of the edaphic habitats are quite mobile (e.g. halophytic, marsh or certain fen habitats), while others migrate only rarely (rock or other fen vegetation types). Some habitats though regenerate admirably on spot, yet never invade new areas; for instance, rock vegetation, acidophilous woodlands, grasslands with woodland origin. Others has almost the same regeneration potential values on spot as on the place of the neighbours, e.g. some steppe woodlands and shrub habitats on their own clearings, or some habitats of secondary origin. Certain rock habitats, some fen and riverine vegetation types and some of the close woodlands regenerate well on spot, but almost never on old-fields. There are some habitats, which has high regeneration potential on the place of the neighbours, but has low values for the old-fields. Most of them are closed woodlands, shrub and certain fen habitats.According to our expectations, the experience gained during the MÉTA mapping will give an impulse to the study on regeneration potential.

Restricted access

Actual distribution maps of vegetation types are important data sources of basic and applied research, respectively. Though there were several attempts to map the actual vegetation of Hungary, the MÉTA program was the first to map all the (semi-)natural habitat types on the whole territory of Hungary. The paper discusses the habitats with treeless vegetation. 45 habitats are presented and discussed. The paper provides additional data on the area and distribution of the habitats mainly at the physical geographical macroregion scale.

Restricted access

Dry oak forests have one of the richest understory vegetation in Europe, but the environmental drivers of this community have been scarcely revealed. In this study, we assessed whether the amount of light, soil pH or stand heterogeneity affect primarily the species composition of this community. We investigaed 332 sampling plots in 40-165 year old managed and abandoned Quercus cerris and Q. petraea dominated forests in North Hungary. Presence-absence data of herbaceous species and seedlings of woody species were recorded in 28 subplots within each sampling plot. Stand structure, canopy openness and soil pH were also measured in each plot. The relationships between stand characteristics and the species assemblage were explored by redundancy analysis, while the individual responses of species and species groups were studied by generalized linear mixed models. Multivariate methods and individual species response analyses provided similar results, the amount of light and soil pH were equally important variables (both of them explained 2.8% of species variance), while stand heterogeneity had a bit lower, albeit still significant role in determining understory species composition (1.9% of species variance explained). Seedlings of woody species preferred shaded (half-shaded) conditions, while many herbaceous species were positively related to light. The effect of the three explanatory variables was hard to separate, since they influenced each other as well. Sessile oak seedlings and herbs typical of dry forests, forest edges, grasslands and acidic soil habitats preferred light rich habitats with homogeneous stand structure and low soil pH. Mesic forest herbs and seedlings of other woody species were related to relatively high soil pH, heterogeneous stand structure and closed canopy. These two understory types were clearly separated regarding composition. This study emphasizes the importance of heterogenous light conditions and mosaic, diverse forest structure (presence of homogeneous and heterogeneous forest patches) during forest management for the maintenance of understory biodiversity.

Restricted access
Acta Botanica Hungarica
Authors: F. Horváth, Zs. Molnár, J. Bölöni, Zs. Pataki, L. Polgár, A. Révész, K. Oláh, D. Krasser, and E. Illyés

The survey results of the MÉTA program are managed with centralised relational database management system (MS SQL 2000) developed and set up in a local area network. Besides the MÉTA database server, a publishing server, an archiving server and a GIS workstation were applied. The core information entities of the MÉTA database are: information subproject, MÉTA quadrate, MÉTA hexagon, (semi-)natural habitat, potential vegetation with numerous habitats, landscape ecology and land use attributes, and surveyor. This information is coded in the nine main tables of the normalised database. In the recent state there are almost 1,500,000 records in the main tables that are managed in 241 independent fields. The published version of the MÉTA database supports the query service, and handles this information in 7 denormalised main tables. This much more redundant version is 11 GB in size. The 20.6% (179 man-month) of the human resources in the MÉTA program were devoted to the information tasks (set up and preparation, MÉTA database and information system development, replenishment and quality assessment, MÉTA query, GIS and printing services) between 2002 and 2007. The basic structure of the MÉTA database version 1.2 is finalised and the main functions regarding data processing have been developed. The accomplishment is higher than 90%, quality assessment is under way, while scientific verification and data harmonisation are started. The area of (semi-)natural and degraded vegetation of Hungary is estimated to 1,800,000 hectares (19.4% of the country) of which the natural, semi-natural is about 1,200,000 hectares (12.9% of the country). All of these are highly fragmented and unevenly distributed over the country. It is shown by several basic figures, professional content and quality measure facts of the database. There is also a fact sheet of surveyors that shapes the important characters of their field experience profile, too.

Restricted access