In this paper we present the main characteristics of a new, grid-based, landscape-ecology-oriented, satellite-image supported, field vegetation mapping method, called MÉTA (MÉTA stands for Magyarországi Élõhelyek Térképi Adatbázisa: GIS Database of the Hungarian Habitats). The goals of the MÉTA method based vegetation mapping program (MÉTA mapping) include the following: (1) to map the actual (semi-)natural vegetation of Hungary; (2) to evaluate Hungarian (semi-)natural vegetation heritage for conservation purposes; (3) to evaluate the present state of Hungarian landscapes from a vegetation point of view; (4) to collect vegetation and landscape ecological data for the prognosis of future changes of vegetation and the landscape. Spatial resolution, mapped attributes and mapping methods were developed to meet these goals.
The MÉTA method uses a hexagon grid with cells of 35 hectares. In the hexagons, habitat types are listed, then the area, naturalness-based habitat quality, spatial pattern in the hexagon, effect of the neighbourhood, connectedness, and threats are recorded for each habitat type. Other attributes are recorded in the hexagons: potential natural vegetation, area occupied by invasive plant species, area of old fields, land use of grasslands, and landscape health status (naturalness and regeneration potential of the landscape in general). One hundred hexagons form a quadrat – mainly for practical, organizational reasons, but also for collecting certain vegetation data at this spatial scale. For standardization of mapping, three different pre-printed data sheets and two different kinds of guides have been composed (Mapping Guide and Habitat Guide) and field trainings were organized. For standardization of estimation of naturalness-based habitat quality and regeneration potential field examples were prepared for each habitat type and each category of these attributes.

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 km2, 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 0236–6495/$ 20.00 © 2008 Akadémiai Kiadó, Budapest 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.

In the present article we give a critical review about those biodiversity indicators that are in connection with the landscape and the vegetation. Besides, we describe the indicators deriving from the only GIS database, which contains ecologically relevant data for the whole territory of Hungary. Quantity (area), pattern, quality and combined indicators are used globally and at the scale of Europe. Most of these are ecologically irrelevant, principally due to the lack of relevant data. Few indicators are actually employed, but developments are still in progress. On the grounds of the MÉTA database (Landscape Ecological Vegetation Database for Hungary), constructed between 2002 and 2008, we propose the use of the following landscape and vegetation indicators for Hungary: habitat area, habitat texture of the landscape, area of old-fields, regional coverage of invasive species, habitat diversity, Natural Capital Index, area of high value natural areas, proportion of naturalness classes, structural habitat connectivity. Some of these indicators would also be applicable in the Hungarian Biodiversity Monitoring System. In the future, there will be serious need for the elaboration and testing of further indicators, as well as for their detailed definition and their introduction in practice.

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).