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)

Studia bot. hung. 35, pp. 151-178, 2004 CONTRIBUTIONS TO THE FLORA AND VEGETATION OF THE ENVIRONS OF BALASSAGYARMAT (HUNGARY) GY. SZOLLÁT

1 and A. SCHMOTZER

2 'Department of Botany, Hungarian Natural History Museum H-1476 Budapest, Pf. 222, Hungary; E-mail: szollat@bot.nhmus.hu 2

Biikk National Park Directorate, H-3301 Eger, Sánc u. 6, Hungary E-mail: andras.schmotzer®ktm.x400gw.itb.hu The authors provide new floristical data of well-defined localities, mostly along the water-courses and those of high groundwater level, within the administrative boundaries of the town of Balassagyarmat, Nógrád county, Hungary, with brief site descriptions and assessments of the naturalness of the vegetation of 12 sites. The authors refer to the results of former surveys concerning the area, and discuss the changes in the flora and vegetation during the past decades. The main source of degradation is the sinking groundwater table and the drying-out of the area, coupled with effects of commercial forestry activity and other forms of human influence. Key words: alder woodlands, Balassagyarmat, flora, Ipoly river, Nyirjes stream, vegetation INTRODUCTION This paper is based on botanical surveys conducted independently by the two authors, but as they both worked in the Ipolyszögi Egerláp, they join in the publication of the results. The survey and evaluation of the state of the (almost) natural and seminatural (partly degraded, disturbed) vegetation within the administrative borders of Balassagyarmat (a town with about 20,000 inhabitants in North Hungary) was started in 1999. Within the larger area, the botanical study of the Ipolyszögi Égerláp, a national level conservation area, was carried out in 1998-1999 and in 2000-2001 based on two different commissions. The main goal was to make a botanical and conservational assessment to provide basic data for the preparation of an environmental program of the local municipality. This paper comprises floristical data as well as short descriptions and evaluations of the vegetation of the areas (with two exceptions) along the water-courses, those of high groundwater level and flooded, along the Nyirjes stream and Ipoly river, and of alder swamp woodlands east of the village of Ipoly szög (Ipolyszögi Égerláp protected area). Studia Botanica Hungarica 35, 2004 Hungarian Natural History Museum, Budapest