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)

The greatest actual threat to these stands is commercial forestry activity, which should be altered to ensure their natural development. The about 100-hectare Ipolyszögi Égerláp (part of the Duna-Ipoly National Park) is a country level nature conservation area lying around the lower reaches of the Nyirjes stream (site No. 11). Most of its plant cover is alder swamp wood (Carici elongatae-Alnetum), being moderately degraded in general sense (combining strongly degraded and almost natural patches). This is a consequence of the area's drying out (worsened by the fluctuations of the water supply). Willow mire woods (Calamagrosti-Salicetum cinereae), large sedge (Caricetum gracilis, Caricetum ripariae), Glyceria (Glycerietum maximae) and reed beds (Phragmitetum communis) and complexes of all these, respectively, also cover remarkable parts of the site. There are patches of riverine willow-poplar woods and the areas 0.5-1 metre higher than all these, are occupied by a different type of alder swamp woods (Angelico syivestris-Alnetum glutinosae = Carici acutiformis-Alnetum). In the Ipolyszögi Égerláp 115 plant taxa were recorded. The difficulty in comparing our data with those registered formerly derives from the fact that matching the exact localities of earlier collections and those of ours is almost impossible. However, it is worth turning our attention to the remarkable differences. Completed our surveys, we cannot prove or confirm the presence of the following species mentioned in the literature: Acorus calamus, Alisma lanceolatum, Allium angulosum, Batrachium trichophyllum, Carex disticha, Eleocharis palustris, Lemna trisulca, Myriophyllum verticillatum, Nuphar lutea, Orchis laxiflora, Peplis portula, Polygonum amphibium, Ranunculus flammula, Rorippa amphibia, Sagittaria sagittifolia, Utricularia vulgaris. The list speaks for itself; perhaps some species have escaped our notice. Yet the species list provides a clear evidence of the drying out of the area and shows changes in the composition of the plant cover. At the same time, this experience determines the tasks of maintenance and rehabilitation of the habitat, supported by observations (e.g. spread of weeds, damage caused by wild animals) referring to the need of increasing the water supply (to recover the water level used to be decades before) in order to avoid further degradation. To ensure the survival of the stands, wrong forestry practices - especially clear-cutting should be stopped (otherwise, especially in dry years, weed invasion or other irreversible change may be the result). Small populations of five protected species occur in the site: Ribes nigrum (10-20 specimens), Carex elongata (10-50 polycormons), Dryopteris carthusiana (10-100 specimens), Ranunculus lingua (10-50 specimens), Hottonia palustris (orders of hundreds or thousands, depending on the water supply and changing in numbers per year; in dry years the terrestrial form, Hottonia palustris f. deminuta is present).