Classification of mesic grasslands and their transitions of South Transdanubia (Hungary)

Relevés from meadows and pastures of South Transdanubia (Hungary) are evaluated by clustering and ordination methods. The relevé selection focused on the Arrhenatheretalia order but its transitions towards other types were also included. The groups of relevés are delimited and described according to differential, dominant and constant species. Ecological conditions of the groups were compared using indicator values. Nine groups were distinguished, four of them belonging strictly to the order Arrhenatheretalia. Each alliance of Arrhenatheretalia presented in the study area (Cynosurion, Arrhenatherion) was represented by two groups. Groups from these two alliances are separated along a light gradient, while groups of the same alliance differ in nutrient values. Within Cynosurion, the nutrient-poor group cannot be identified unambiguously as any syntaxa previously known from Hungary. The nutrient-rich Cynosurion meadows are similar to Lolio–Cynosuretum, however, they show a stronger relationship with wet meadows. Within Arrhenatherion, Pastinaco–Arrhenatheretum is recognised as a hay meadow of nutrient-rich soils. The other meadow type is similar to Filipendulo–Arrhenatheretum, thus raising syntaxonomical problems. There are transitional groups towards semi-dry and wet meadows, one dynamic phase and one outlier group among the other five clusters

Gypsophilo paniculatae-Agropyretum repentis , a new half-ruderal weed association

This paper deals with a new Gypsophila paniculata dominated half-ruderal Pannonian weed association. In order to identify this vegetation type, samples were compared with some dry and semidry Central European weed associations of Agropyretalia repentis. The community studied seems to belong to the Artemisio-Agropyrion repentis alliance. Based on results, the Gypsophila paniculata dominated dry half-ruderal sand grass stands are classified in the frame of a new association under the name of Gypsophilo paniculatae-Agropyretum repentis . It can be divided into two subassociations, notably a more natural typical one rich in species, replacing disturbed sand grasses → typicum with Artemisia campestris , and another type containing less species and exposed to much stronger disturbance → aperetosum spicae-venti subass. nova