Dr. Fűköh Levente szerk.: Malakológiai Tájékoztató 12. (Eger, 1993.)

SZABÓ, S.: The effect of becoming waterless and experiments of livingplace reconstraction on Monusca living in the soid laces of Upper Kiskunság

The sodic livinplaces are extremely varied because of the multicolourness of substratum, water, flora and exposition. The dispersion (distribution) and diversion (variety) of malacocoenosis tend towards the extremes because of the oecological potencialities and autoecological extremes here (Szabó, S. 1986). National Park of Kiskunság, territory number III. The number of species has grown with 67% compared to the beginning of the experiment, but at the same time the absolute quantity of individuals number hasn't changed. The reason of the fact - mentioned above - is that the individuals number of Anisus spirorbis has regressed remarkably and this can be explained as a sort of gradational presentation of two competing species {Gyraulus albus, Segmentina nitida) Reeds is the richest in species and number of individuals. The Physa acuta and the Gyraulus albus are spreaded equally in marschland parts. At the beginning of the experiment the Anisus spirorbis was equallly spreaded but later it showed cummulative (enriching) and insular (island resembling) dispersion. The cummulative presentation in large number of the big sized Lymnaea stagnalis and the Lymnaea peregra is very interesting in the open watered lake. Dispersion of the these species is insular or accidental uncommon, that the quantity, number and spread of the species are considerably less in the alimentary canal than in the (Fehérszék). The living species are half as much in lake "Kisréti" and "Kelemenszék" examined as control. The number of individuals is very low and the dispersion is insular or accidental. The Anisus spirorbis the only one which presents in large number at either place in cummulative dispersion. National Park of Kiskunság, territory number II. I have got to know thorougly this big part of the KNP for 3 years. I took a lot of seasonal interspecific pictures about the livingplaces. They became specific because of watermoving and flora. The alimentary canal is the richest in species (9), but remarkable that the interspecific characteristics of the species are least favourable, there are 6 species' in lake signed "A", most of them in the north-east corner of the reeds near the receiver mouth. There are only 2 species in lake signed "B". There are 10 artifical fish-ponds between the alimentary canal and the lake signed "A". The extention each of these ponds is about 10 ares (1000 m ). There is no connection between the canal and the ponds or the canal and the lake signed "A". The ponds are connected with each other only. They are fed by precipitation and water coming through the soil. There is certain open water in pond number 1 but all the others are covered by vegetation. 8 species live in these fish-ponds. Division, individual number and dispersion of these species depend on the potentialities of the livingplace (see next chaters). In wiew of all territory of Apaj the Anisus spirorbis is cummulative and on certain territories the dispersion is equal. Dispersion of the next species - such as: Lymnaea peregra, Lymnaea stagnalis, Planorbarius corneus, Planorbis planorbis, Armiger crista and Segmentina nitida - is insular but a lot of them have much more favourable characteristic in the fish - ponds. Dispersion of the other species is inequal with negligible abundancia. The dates of Apaj are nearly the same as my experience from KNP control territory number II (Szabó, S. 1990-b).