B. Papp szerk.: Studia Botanica Hungarica 38. 2007 (Budapest, 2007)

Szollát, György, Seregélyes, Tibor, S. Csomós, Ágnes; Standovár, Tibor: The flora and vegetation of Gödi Láprét near Göd, Pest county, Hungary

the retreat of the species might be related to draught, which has become much worse recently, or perhaps to the increasing quantities of nitrates oozed into the soil of the surrounding areas reached the Gödi Láprét through the underground water. Fluctuation is very visible in the population of Orchis morio: in 1992 only 5-10 flowering specimens were seen, while in 1997 nearly 500, and in 1998 only a few specimens flowered again. There is a similar case with the Orchis ustulata. In 1992 a few dozens of specimens were counted, in 1997 there were 500-700 flowering individuals, but 1998 we could hardly see any. Ten to fifteen specimens of Ophrys sphecodes occurred on two sites in 1992, but one of these localities disappeared in 1997 because of burning, and on the other place there were still a few flowering specimens in 1998. The populations of Iris sibirica and Veratrum album became stronger year by year. We noticed little change in the reed expansion in the rich fen sites, but the process goes on undoubtedly. The aggressive and striking spread of Cladium mariscus seems to be highly dangerous for the fen vegetation. In 1992, it occurred only on a few sites each covering a few square metres, but by now it has taken over large areas in the purple moorgrass meadows and is even more abundant on the rich fens, occupying a rather large proportion of their area. CONCLUSIONS Monitoring of the Gödi Láprét has been continuing for 14 years. During this period of time two detailed surveys have been made, and the completed studies include vegetation maps and maps showing the occurrence of the protected plant species. The Gödi Láprét is one of the most valuable sites of the Pesti-hordaléksíkság with a vegetation of mostly semi-natural state. The presence of 325 plant species - including 35 protected taxa, some of them having significant populations - on a rather small area of 15-18 hectares well illustrates the floristical richness. Habitat diversity also supports this colourful vegetation: both dry sandy grasslands of the sand dunes, and the adjacent fen and wet grassland of the dune slacks are found in a relatively small area. Among the huge problems for the flora and vegetation is the decreasing water supply for the water demanding of wetland plant communities due to the housing development in the adjacent area (and partly the golf course and some potential, illegal intervention of the landowners around). The fens and meadows are also threatened by the process of "natural" degradation, that is, the aggressive spread of certain plant species. The planned conservation management against this is scything or mowing, but this was