B. Papp szerk.: Studia Botanica Hungarica 37. 2006 (Budapest, 2006)

Bauer, Norbert: Open sandy grasslands of the Bakony region

The species-poor, but relatively heterogeneous samples of the Br group represent the rather degraded sandy grassland stands typical of the Bakonyszentlászló-Fenyőfő area, and the secondary pioneer vegetation of disturbed surfaces with Bromus tectorum L., Eragrostis minor Host, Chondrilla juncea L. and Corispermum nitidum, Eestuca vaginata, Ambrosia artemisiifolia. In the case of the supposed sandy grasslands situated in other, more southern, parts of the Bakony region (Nagytevel, Sáska, Hegyesd, Salföld, Szentbékkálla, Sümeg), the limeless quartz sand bedrock (through its natural presence) excludes the appearance of basofrequent species, thus the more typical species of the Festuca vaginata associations are absent (for phytogeographical reasons) from the flora of these sample areas. From a coenosystematical aspect these Corynephorus canescens grasslands (Cc group) can be identified mainly with the Thymo angustifolio-Corynephoretum association, but it is indisputable that its probable stands are not so typical. Some major species of Corynephoretum (Spergula morisonii Boreau, Carex arenaria L.) of the Atlantic dune vegetation in Germany (Spergulo vernalis-Corynephoretum canescentis (Tx. 1928) Libbert 1934, VioloCorynephoretum Böcher 1941) gradually disappear south-eastward (they partly reach the region of Marchfeld), and according to our knowledge they are not present in the Hungarian flora. Teesdalia nudicaulis (L.) R. Br. is an exception, which can be found in certain areas of southern Transdanubia. Besides Corynephorus canescens, in the stands of the Bakony region Jasione montana and Rumex acetosella are frequent, but Potentilla argentea L., Hypochoeris radicata L., Hieracium pilosella L., Scleranthus annuus L., Thymus serpyllum are infrequent, although these are typical species forming associations. Some important species of the locally nutrient-poor sandy and pebble surfaces (e.g. Calluna vulgaris (L.) Hull, Moenchia mantica (L.) Barth, Gagea bohemica (Zauschn.) Schult, et Schult., Aira caryophyllea L.) can also be found in the samples. It impedes the coenotaxonomic classification of stands besides the generally typical species poorness (less constant and subconstant species) that these may be taken over by weeds easily. The great frequency of several weed species - being one factor also turned out to be significant during the statistical evaluation - refer to severe disturbance of the majority of sampling areas (Ambrosia artemisiifolia, Conyza canadensis (L.) Cronq.). Cerastium semidecandrum L., Scabiosa ochroleuca L., Erysimum diffusum Ehrh., Silene otites, Euphorbia cyparissias do not show relation to any of the other types of the more frequent species of the sandy grasslands of the Bakonyalja. The latter two statements have also been confirmed by the representation of the PCA biplot. Near Nagytevel (Öreg-hegy-alja) the open Corynephorus grasslands are adjacent to grasslands dominated by Koeleria majoriflora (CcK) on certain closer ar-