B. Papp szerk.: Studia Botanica Hungarica 35. 2004 (Budapest, 2004)

Szollát, György; Schmotzer, András: Contributions to the flora and vegetation of the environs of Balassagyarmat (Hungary)

Jasione montana, Campanula rotundifolia, Hypochoeris radicata, Anthemis ruthenica, etc. Besides the (temporarily stabilised) secondary steppe patches there are pioneer stands which exhibit a relatively early phase of regeneration. After some of the traditional former land uses, such as grazing and scything had been discontinued, we see obvious changes in the plant composition of the grasslands. By now big masses of weeds and phytosociologically indifferent species occupied the site, e.g. Calamagrostis epigeios, Carex hirta, Poa angustifolia, Arrhenatherum elatius, Cynodon dactylon. The spread of agressive adventive weeds, among them Ambrosia artemisiifolia, Asclepias syriaca, Erigeron canadensis, Stenactis annua is also considerable. CONCLUSIONS Until recently no systematical botanical exploration in the surroundings of Balassagyarmat was carried out. The majority of the floristical data collected earlier is a result of phytosociological surveys made at larger scale. Our recent survey of the remnants of the original vegetation began with recording the species and evaluate the state of the vegetation in 1998. The majority of the area consists of arable land and tree plantation (mainly with introduced species). A smaller portion of the study area is covered by almost natural, seminatural or secondary vegetation. The upper reaches of the Nyirjes stream run in narrow valleys and are lined by stream ash-alder woods (Aegopodio-Alnetum) of almost natural state (site Nos 6 and 7). 77 species were listed here, included three protected ones, Ribes nigrum (50-100 specimens), Dryopteris carthusiana (50-150 individuals), Dryopteris dilatata (1-10 specimens). Despite the buffer zone is lacking around these county level nature conservation areas, the sites are relatively free from weeds, thanks to the significant differences between the alder woods and the surrounding habitats. The major actual threat to these stands today is commercial forest management. To ensure the undisturbed survival of these communities, all forestry activity should be managed with the priority placed on conservation. Along the middle reaches of Nyirjes stream almost natural submontane stream ash-alder woods (Aegopodio-Alnetum) and alder swamp woods (Angelico syivestris-Alnetum glutinosae) occupy the widened valley (site Nos 9 and 10). Among the 62 listed taxa there are two protected ones, Ribes nigrum (100-150 specimens) and Dryopteris carthusiana (200-300 specimens). These county level nature conservation sites are surrounded with tree plantations (established with introduced species) and holiday resorts practically adjacent to the conservation land.