B. Papp szerk.: Studia Botanica Hungarica 36. 2005 (Budapest, 2005)

Szollát, György; Standovár, Tibor: Botanical values of the Öreg-hegy and Juhász-halom near Csomád

Plantago arenaria, Kochia laniflora. Gypsophila paniculata increases its abundance as a response to disturbance. In addition, several less specialised dry grassland species - also characteristic to the sand steppes - are present: Fumana procumbens, Erysimum diffusum, Carex liparicarpos, Silene otites, Melica transsylvanica, Potentilla arenaria, Euphorbia seguieriana, Alyssum tortuosum. To our best knowledge several important sand steppe species that occur on the Somlyóhegy near Fót (FEKETE and KOVÁCS 1982, SEREGÉLYES 1990), the Pesti-hordaléksíkság and on the Szentendrei-sziget (SEREGÉLYES et al. 1993, SZOLLÁT et al. 1992) are missing. They include: Corispermum nitidum, Dianthus serotinus, Iris arenaria, Peucedanum arenarium, Sedum hillebrandtii. Some common species of meadow-steppes and sand steppes show characteristic habitat preference on the Öreg-hegy. Globularia punctata and Carex humilis prefer rock steppes on sandstone, whereas Carex liparicarpos and Potentilla arenaria are more abundant on sand. Iris pumila grows mostly on sand, while Adonis vernalis has high abundance in meadow steppe but is almost lacking from sand. Helichrysum arenarium (otherwise typical sand steppe species) and Pulsatilla pratensis subsp. nigricans have their only occurrences at the edge of meadow steppe. There are some sand meadow-steppe patches on the lower part of the southerly slope. Stipa capillata dominates in these patches with Festuca rupicola, Botriochloa ischaemum and Chrysopogon gryllus as important grasses. Of the typical sand meadow-steppe species Astragalus excapus, Hieracium echioides, and Seseli varium occur. In addition to the common dry grassland species (not listed here), other valuable species include Adonis vernalis. Iris pumila, Carex humilis, Vinca herbacea, Colchicum arenarium. Highly degraded grasslands The calcareous sandstone plateau between Oldal-hegy and Öreg-hegy is covered by extensive fallow fields that used to have different cultures and were abandoned in different times. Most of them have been invaded by aggressive weeds such as Solidago gigantea, Ambrosia artemisiifolia. However, some parts have recovered quite well. The most remarkable patch is dominated by grasses (Stipa capillata, Festuca rupicola, Botriochloa ischaemum), with small share, but relatively high species richness of dicotyledons. Besides common species, among others Adonis vernalis, Globularia punctata, Allium paniculatum subsp. marginatum occur. The grasslands occurring on the western part of the south-facing slope grow in the openings of declining Robinia plantations. These degraded grasslands (partly recovering but also threatened by shrub invasion) are dominated by the competitor Stipa capillata and the disturbance tolerant Botriochloa ischameum with some