Dr. Fűköh Levente szerk.: Malakológiai Tájékoztató 13. (Eger, 1994.)

SZABÓ,S.: Data to malacologie valuation of Hungarian waters

Data to malacologie valuation of Hungarian waters S. Szabó ABSTRACT: The author points out the problems concernina SHANNON-WIENER diversity used in evaluation of habitats. He proposes to start using „malacological value number" which doesn't neglect the abundancv of species, oecological type and soread in Hungary. There are 49 species of watersnail living in Hungarian waters (Richnovszky, A.-Pintér, L. 1979). They turn up several wav according to their spread (Pintér, L. et alii. 1979) and association of them. Caves are verv poor in species but slowlv moving or inmovable waters overarown by plantes are rich in them. Oecological groubing of molluscs occurence is done and based on Lozek, V.: Entwicklung der Molluscenfauna der Slovakei in der Nacheszeit (Lozek, V. 1965) over Europe. For measuring diversity entropy information (SHANNON-WIENER diversity: „H

S

" is used (Wilson, E.-Bossert, W. 1981). The „H" diversity index is higher the examined habitat is also diverse. SHANNON diversity is so general in oecological literature and it can be a base for comparison with other habitats or with other associations of the examined habitat. The mistake of SHANNON-WIENER entropy is that the species are considered to be equal in rank it neglects the really are species. On that places where there are only a species (for example: one endemical „RED BOOK's" species Sadleriana pannonica living in mountain Bükk, or the most ordinarv water spail Anisus spirorbis living in sodic water of „Apajpuszta" in Kiskunság) we can not speak about diversity, but in spite of this we definitely feel malacological value's difference the two places. This problem is solved if beside S H ANN ON-WIENER diversity we examine the malacological value of the habitat (Szabó, S. 1994). My = malacological value of the habitat s = number of turned-up species PA-Í = abundacv of species „i" m

s = malacological value number (see chart) The malacological value number (ms) can be counted by adding up the LOZEK's division into group /1-10/ (L) (Lozek, V. 1995) and the percentage value - turned up on „UTM" network - of the spread of the species in Hungary (e), at last the sum has to be divided by two. Malacological value number s ms = (L+e)/2