B. Papp szerk.: Studia Botanica Hungarica 34. 2003 (Budapest, 2003)
Szurdoki, Erzsébet: Peat mosses of North Hungary
Ín press). Some of these contain new data and information about North Hungarian Sphagnum occurrences (NAGY 1996, 2002, LÁJER 1998a, b, NAGY et al. 1998, SZURDOKI et al. 2000, in press). A recent study by SZURDOKI and NAGY (2002) summarised the recent knowledge about Sphagnum dominated mires and other peat moss occurrences of North Hungary. The aims of the present study are the following: (1) to compare the recent distribution of different Sphagnum species with these based on earlier data in North Hungary, (2) to describe their population sizes and (3) their populational changes during the last decades and (4) to establish their conservation status in the region. STUDY AREA The investigated area has mainly mountainous-hilly and partly plain relief (from 150 to 1,015 m), containing the whole Northern Mountain Range, the Gödöllő Hills and the Northern Hungarian Plain (Bereg and Nyírség). Geologically, this area is very diverse, the bedrock is also variable, partly calcareous, partly volcanic or alluvial. For the mountains and the proximity of the Carpathians, the mean annual temperature is lower (8-10 °C) and the mean annual precipitation is higher (600-800 mm) than the average values of the whole country. The wintertime precipitation is also higher in this region, which is a very important factor in securing positive water balance of the mires. The colder and more humid microclimate helps the establishment and survival of Sphagna. The montane region is dominated by deciduous forests and the plains by open forest-steppe woodlands. There are numerous small and isolated peat moss dominated mires and peat moss occurrences in North Hungary. These small mires are about 1-2 hectares in size, developed mostly in depressions or in oxbow lakes. The peat moss occurrences are small, covering only square metres or square decimetres. The Sphagnum patches are developed on wet soil of forests or in open areas, among streamlets and springs or in tall sedge vegetation. SZURDOKI and NAGY (2002) summarised the present knowledge of these habitats. In this paper the following sites were investigated: Csömöri-tó, Nádas-tó, Nyírjes-tó, Kis-tó, Nagy-tó, Futyó-völgy, Csipkés-kút, Kis-Mohos, Nagy-Mohos, Lókosár, Zemplén Mts, Nyíres-tó, Báb-tava, Bence-tó, Zsid-tó, Navat, Bátorliget Nature Reserves, Júlia-major. Figure 1 shows the distribution of the investigated sites. Csömöri-tó is situated in the Gödöllő Hills, at about 150 m a. s. 1. Peat mosses were described from the floating island situated in the centre of a small lake dominated by Salix cinerea and Thelypteris palustris. There was a fire in the 1980s and the Sphagna have disappeared (STOLLMAYER-BONCZ 1982, 1999). Nádas-tó totalling about 2,000 m 2 , is found near Nagybárkány in the Cserhát Mts at about 360 m a. s. 1. The shallow depression is covered mainly with willow swamps and partly with Phragmites. Peat mosses live under the willow shrubs (MÁTHÉ and KOVÁCS 1959). Nyírjes-tó is situated in the Mátra Mts, near Sirok village at about 250 m a. s. 1. This bog has developed in a basin of about 9,000 m 2 . The central part is more or less open (with Carici lasiocarpae-Sphagnetum), mainly surrounded by Salici cinereae-Sphagnetum and the outer part is a lag zone (MÁTHÉ and KOVÁCS 1958). In the 1990s the water table was very low and the lag zone was dry, but at the end of the decade the basin has filled up; the high water table is high from the central part to the lag zone (SZURDOKI and NAGY 2002).
