No abstract

A new element of the Hungarian adventive flora, Panicum dichotomiflorum, has been discovered in Hungary recently. A short characterisation and its Hungarian distribution are presented.

1 This manuscript is contextually identical with the following published paper:Lukács B.A., Mesterházy A., Vidéki R., and G. Király (2016) AbstractEstimating the extent of biological invasions is critical in predicting the effect of exotic species. We investigated the occurrence and number of alien freshwater plants and give information on the composition of alien aquatic flora, their trend in time, invasion pathway and their invasive character.

In this contribution, new data concerning the distribution of vascular flora alien to Italy are presented. It includes new records, confirmations, exclusions, and status changes for Italy or for Italian administrative regions. Furthermore, three new combinations are proposed. Nomenclatural and distribution updates published elsewhere are provided as Suppl. material 1.

The first version of the map of the Hungarian vegetation-based landscape regions were prepared at the scale of 1 : 200,000 (1 km or higher resolution). The primary goal of the map was to provide an exact background for the presentation and evaluation of the data of the MÉTA database. Secondly, we intended to give an up-to-date and detailed vegetation-based division of Hungary with a comprehensive nomenclature of the regions. Regions were primar- 0236-6495/$ 20.00 © 2008 Akadémiai Kiadó, Budapest ily defined on the basis of their present zonal vegetation, or their dominant extrazonal or edaphic vegetation. Where this was not possible, abiotic factors that influence the potential vegetation, the flora were taken into consideration, thus, political and economical factors were ignored. All region borders were defined by local expert botanists, mainly based on their field knowledge. The map differs in many features from the currently used, country-wide, flora-or geography-based divisions in many features. We consider our map to be temporary (i.e. a work map), and we plan to refine and improve it after 5 years of testing.

The Pannonian region is situated in the Carpathian basin where forests have been used intensively for centuries. The article shows a map and a tabular overview of the forest reserves featured as forests ''left for free development'' of the region, and presents the most important stand structural characteristics of beech, mesophytic and thermophilous deciduous forests surveyed recently. The sampling points of six sites were selected to provide preliminary descriptive statistics according to the main types and abandonment status groups (recently managed, long abandoned and old-growth or primary stands) of these forests. In oldgrowth and primary stands the composition (list and mixture ratio of tree species) and stand structure characteristics [gap class distribution, stem density, distribution of relative crown classes and broad diameter at breast height (at 130 cm) classes, density of thick snags, and the amount of lying dead wood] proved to be similar to other European deciduous natural forests, while the abandoned and recently managed stands indicate that these forests are in a transitional stage towards natural ones.

Phytogeographical regions have been set up traditionally on the basis of the flora. Several examples indicate that the potential natural vegetation is also suitable for this purpose although the flora-and vegetation-based boundaries do not necessarily overlap. We define a vegetation region as an area where the physical geographic features are rather uniform, and which consists of landscapes with floristically/structurally similar vegetation and/or their repetitive mosaics. In this paper, we delimited the boundaries of the Pannonian region based on the distribution of characteristic plant communities. The line runs most often on the border between Quercus cerris-Quercus petraea and Carpinus betulus/Fagus sylvatica dominated landscapes. We provided descriptions of the potential vegetation on both sides of the boundary. The region has an area of 167,012 km 2 . The region is either in direct contact with the neighboring regions (e.g., Western Carpathians), or is separated from them by transitional areas (towards the Eastern Alps), and character-poor areas with non-Pannonian, non-Alpine, non-Dinaric vegetation (in the southwest to the Western Balkan). Often, the boundary does not coincide with the boundary of the Pannonicum floristic province. We found that vegetation region boundaries can help reevaluate long-established floristic region boundaries. The boundary of the 'floristic Pannonian region' also requires revision based on integrated distribution databases and statistical analyses. We argue that the method applied here is simple, repeatable and falsifiable. Our map provides an opportunity to the European Union to use a scientifically more sound biogeographical circumscription of the Pannonian region in her Natura 2000 and other programs.

No abstract