THE MALACOFAUNA OF DUMPS OF THE SODA FACTORY IN CRACOW

On the dumps of lie Cracow Soda Factory llere occur molluscM assemblqes comprisiftt 13 taxons. The assemblages display a succession connected with three phases in lhe development of vegetation. which occurred wilen the slopes of the dumps were getting overgrown. The succession phases correspond to the assemblage with ~ ._. lie assenmt.ge with Pqp6and lhe assemblage will ~-'""• respectively. A Wometrlcal -.lysis of populalons of 7 snail species has shown that lie populatlons do not differ from those oecunlnt In natural hllbltats. The diMrslty of the assemblages Is very high: xerophilous and hygrophilous species can be found together In one assemblage.


Introduction
In the southern part of the city, In the valley of the WHga River, large dumps of the Cracow Soda Fadory (the previous name: Solvay Factory) are situated.These are reservoirs covering at large an area of about 60 ha, bordered with high banks of slag and unburnt Ume.The reservoirs are successively getting filled with sludge containing a suspension of CaC03 (postcaustic slurry) and With a solution of CaCI2 (postdstil slurry).Both the components are mixed together in various Pl'oponjons.The slopes of the banks are 10 -15 m high and lie at an angle of about 400.Water With calcium carbonate and calcium chloride percolates through the banks at some places and Is then disposed to the WHga River by a system of ditches and cuttings.On the slopes of the dumps, SOIIa rich in calcium as well as in chlorine and sulphur compounds are formed.The soils are largely dry but in the zones where water exudes, very dump habitats appear to form a mosaic of l'llUch varied environmental conditions.
The dumps are partly covered with vegetation.On the old slopes, vegetation has lasted for 20, ao, or even 50 years, uninterruptedly, while in the places where the reservoirs are extended, Vegetation has been completely devastated by getting bestrewn with limestone rubble and hot slag.DetaUed floristic and phytosociologlcal studies of the dumps In question were completed by TRZC!Nst<A-TACIK (1966).That author found 275 plant species to occur there and described t~ succession on the slopes and on sedlments that filled the dried-out reservoirs.The succession comprised three phases of an increasing degree of substrate covering.These were: I -the Cht!l/IMent!!I'Kln 111flUS/issinU11-Cae1701'1'hi1t/m minus phase of a great share of mosses and annual and biennial plants; 11 -the Afrhen.l/heretume/1/ti:Yis phase of numerous meadow species and perennial plants; Illthe phase with

Material and methods
SnaH sheDs were collected on three localities corresponding to the particular phases of the succession ot plants on the heap slopes (Fig. 1 ): Locally A-a heap situated on the right-hand side or the valley ot the Wllga River, between the streets Jugowlcka and MySienicka.onty part ot the southward slope is covered with vegetation (succession phase 1).Locality B -the eastward slope ol the same heap, almost completely overgrown With plants (succession phase 1).Locally, exudes ol water are observed.
Locality C -a heap on the right-hand side of the valley, between the streets Jugowlcka and Borowinowa.The northward slope is covered with a rich vegetation (succession phase Ill) with numerous clumps of small trees and shrubs.Some parts ot the substrate are humid.which Is chiefly observed within the lower part of the slope.
On each localily, three samples weighting 4 -5 kg each were taken, so as to contain a material accumulated on the surface and the soil.The samples were desiccated and sieved with ~5 km ---4 r-~, @ l ,1. 3.
-J' several sieves to pick an mollusc sheDs and sheH pieces that could be determined.The material Was then cleansed by steeping in diluted Perhydrol.More than halt the material were empty snail shells but an the species found were also represented by living Individuals.The whole of the COllection comprised nearly 1 ,500 specimens.
The number of the sheDs of each taxon has been presented on a logarithmic scale.To make a comparison between the assemblages.a quantitative taxonomical method with the use ol Stalnhaus' dSA index (ALEXANDROWICZ 1987) has been applied.Populations of several specie.s selected have been characterised.the toRowlng characters beeing considered: sheN height -h; shell width -w; degree of shell elongation -e " h/w; asymmetry index -a, measured as a proportion between the largest and the smaUest diameter (width) ot the shell: spire size index -s.calculated according to the formula s .. (h -p)/h, where p Is the mouth height.The accuracy ot the measurements Is 0.1 mm.Each assemblage analysed has been characterised by the fOllowing Indices: n -number of specimens; x -arithmetic mean; se -standard error of arithmetic mean: sd -standard deviation; v -variability index: M -range of arithmetic mean: Drange of assemblage diversity.The intervals ol M and 0 consider a confidence level of .05(95%).The Table 1 The occurrence of mollusc species on dumps of the Cracow Soda Industry.Ul IV

Molluscan assemblages
The molusc fauna In question comprises 12 species or snails and shells of slugs conventionaRy referred to as Li»>t:idle.The distribution ol particular species and the number ot specimens In samples representing the described localtles are non-uniform.On each locality, a distinct rnolluscan assemblage occurs, corresponding to a particular phase of plant succession.The assemblages comprise dllferent numbers or species and have distinct typical and predominant taxons (Tab. 1 ).
The molluscan assemblage connected with the first phase ol the plant successlort (locality A, tamples 1-3) comprises 6 taxons.The character species ol the assemblage is lif!lk't!'la a!JIM The shells of the snal are numerous on the locally In question, whUe in the remaining samples.If at al, there are ody single specimens.FOU' other species ol the assemblage show a high degree ot constancy.011 of them, 1 Is Vllonli ctiSiata that occu-s in a considerable number, whereas The lt*d phase of the plant succession (locally c. samples 7-9) is connected wlh an ....._ge ol 11 taxons.An Increase In the degree ol shadow is reflected In the presence of ~ i1clmlll that can be regarded as the characteristic species of the assemblage.Its '-'nber In al the three samples was smal, to be sure, tu on the other locallies the species was not ICU'td at al. Similarly as of locdy 8, the donWlart species of this locality are: C~ ~ v...._ ~ and V. ct1S'IM4 whereas l/lrN /)ll!tiUaidl occurs with a high Conateney.The presence ol such species as SUr:t::i1tM ptfi/6 and Zmtt:M*s /1/lit:Jt/s refieels a C<lnsiderable hU'nldty of the substrate In shady hablats.localy, there were found single shels ol the ~ ~ Ht!ltl;r ptJIJ'IIIil.and Ct/piN nt!mt¥11s.

Biometrical analysis
The measurements of the shels of snails of the genera: ~ C~ Ptpi/8, Y~ and Za.li~s have enabled the author to evaluate simple statistical indices and to draw diagrams characterizing the studied populations (Tab.2. F10. 3).Size-alterations in the shell of HekeJW obi'B in the successive growth-phases have also been determined.
The species is unevenly distributed on the heaps.tt was found on locality B but only it was only In one sample (sample 6) Its number was significant.The parietal lip having a simple and little   (1963) are wider than the ones determined for shels coming from the heap.This Is due to the fact that In the former case these are differences between the extreme values (the biggest and the smallest shells of the set) whereas in the latter they were calculated on a basis of the value of standard deviation, considering a confidence level of .05. hence the latter represent 95% of the set The present measurement results indicate that as concerns the basic blometrlcal characters, specimens of C~ mi'Jintln that occur on the heap In Cracow do not differ from those which can be found In natural habitats.
This Is a species which was found In all samples, being numea:ousty represented on localities B and C. Both the analysed populatlons comprised specimens of one size (h • 5.69 mm :!:.0.04 ... 0.05).The shells from locality C are somewhat more elongated than those from locality B, but the difference is not significant on a confidence level of .05.The dimensions of the shells, the elongation, and the height of the spire are contained within varlabHity ranges of the discussed species that were given by various authors.The size of the measured shells usually corresponds to the lower parts of the ranges.This is due to the lack of biometrical studies on populatlons of this species, that lt is impossible to make true comparisons and to evaluate the significance of the differences.The populatlons of Coc/Jkqt.vhiKir:il of the Wawel Hill In Cracow, described by the author (ALEXANDROWICZ 1988) comprise shells of a varied size.On the westward hillSides there were found specimens that had the same characters as those found on the heap, while the populatlons that occurred on the northward and eastward hillsides comprised bigger shels.ROI.JssEAu (1985).That a'-'hor hu shown that West Ewopqn populations ol the species have smaller shells than those Inhabiting East Europe.ll can be supposed that the specimens Inhabiting the heap In Cracow do not differ in their characters from the ones of natural habitats.
The species have been found in all the analysed samples though numerous populations of it occur only on the localities that cprrespond to the first and second phases of plant succesSion.
The size of the specimens, as determined by the larger diameter of the shells, shows a marked variation.On locality A, the specimens are smaller than on B. the difference between the arlttvnetlc means of the character Is significant on a confidence level of .05,though the variability ranges expressed by standard deviation on the same confidence level overlap each other.At the same time, the population from locality B shows a sNghtly larger sheH asymmetry.Both the said populatlons are contained within the variability range of the species given by several authors (LOZE< 1956, URBANSI<I 1957).There are no blometrical data from other areas, hence it Is Impossible to draw comparisons.
This Is a species found in all samples but numerous on localities B and C, the specimens of the previous locally being somewhat bigger.As In the case of the latter species described above, the difference expressed by the arithmetic means of the shells is significant on a confidence level of .05but the variability ranges partly overlap each other.In spite of the lack of a quantitatively analysed material for comparison.it can be supposed that the size of the 1/aJ!onM ~Hs coming from the heap In Cracow does not differ from the size of specimens of populatlons that Uve in natural habitats.
on locality C there has been found a population of the species that comprised more than 40 specmens.The shells have a varied size and whorl number, so there are both mature and Juvenile specimens among them.The arithmetic mean of shell diameter, determined for such a popUitlon, does not extend 4.5 mm.but the said collection also contains individuals reaching discerned on the shells.Hence, it was dilllc~ to obtain an appropriate set for a standard biornetrical analysis, but l was possible to determine sheft size alerations In the successive Ottogenetic phases.For such reconstructions, l Is convenient to use growth lines or mos that can be seen on the shell, which correspond to temporary decreases in growth, being connected for instance wth the wtrter period.However, this method was not applied owing to the lack of data concerning the conditions under which the rinOS had been formed.A set of n • 116 shels was divided ~o subsets of a whorl runber ranging from 1.5 to 4.5 (7 subsets).For every subset, the arithmetic mean and standard deviation of the largest diameter of the shell were determined tr~g.4).The shen grew more rapidly In the earnest phase (from 1.5 to 3.0 whorls) than later on Ctrom 3.0 to 4.5 whorls).The variability ranges of particular subsets.determined on a confidence level or .05(95l.probablty) as the Intervals: x !. 1.96 sd overlap each other, which Indicates a considerable size variation In shells of a particular .number of whorls (Fig. 4).In the studied "-lerial.the biggest specinens had 4.5 whorls and a diameter of 15.4-15.8mm.Similar Characters were displayed by specimens of the Wawel ..,.In Cracow, colected on the IOW!ward locallles (AL.EXAM:>ROWICZ 1988).TertatiVe data given by several al.lhors Indicate that the population of HtMit:tfrtfl aiJIIil occurring on the heapS of the Cracow Soda Industry is not liQnmc.n~vciHerert from populatlons lnhabiling other locallies.

Fig. 2 .
Fig. 2. Tax-.nie81 de"*ogr11m of lhe mollusc.nassem~~~ates of a dump of the Soda Factory of Cracow.dSA -taxonomlc81 distances, A, 8, C -localities of the fauna.1-9 -samples 5...6 mm.The latter correspond in their size to the average size of the mature individuals occurring In natural habitats.Numerous sheHs of the snaH occured on locally A, to create local rich accumulations.In the populatlons of empty shels, as well as in those of living specimens, one could find individuals of a various size and a larger or smaller number of whorls that were In various growth phases.No charader that wOJ,Jid Indicate that the individuals were mature or had finished their growth were L .4. Size cMfttes In lrWIMfl ,.,_ with ., • .Lshell ._..,, w -......, of whorls, •+ 2 sd --ialllllty 'MfO ot shell size C1/am1prostts eptpe/Os ot a lull surface cover.As the succession were devel~.scarceshrubsandtrees appeared to form clumps and gatherings within which partly shaded habitats could develop, consequently.The most numerous plant species occurring in the habitats is Belu/1 11errucosa.whereasPiJI)liUstremull.S1/t% ll'lp#IS.Ahus tremu/a.Slm/Jucus nipra.andC/'1/epusmonopyn1are somewhat less numerous.The dumps are situated in a depression.on the flat bottom of a rather broad valley.atthealtitude of 210 m a.s.L The climatic conditions of the area correspond to the characters of the climate of Cracow that were described in detail byHESS (1967).The main climatic parameters The characters ol the macro-and mesoclimate are modified by local microclimatic conditions which have not been studied.ll is probable that the temperature on the slopes of the heaps Is heightened as compared with the temperatt~e of air.which phenomenon can result in shortening the period of the srllJw-cover lasting (TRZCINsKA-T ACIK 1966).A similar phenomenon was observed in Upper Silesia.The pollution of the environment can be characterised by the value of mean concentration of S02 in air, which Is 90 mg per cu.m, and that ot mean tall of dust.which is 180 t per sq.km per year.

Table 2 D
BERGER (1963)e -a typical character ol the species -was observed in many specimens.To determine statistical indices characterizing tne shell dimensions, a population of n '"' 49 specimens was used (Tab.2).Biometrical characters ol the population correspond to data given by several authors for various countries of Europe(SOOS 1943, LOZEK 1956, URBANSKI1957, LIKHAREV   & RAMMELMEIER 1962, KERNEY & CAMERON 1979).1t is worth of attention that the present biometrical data fully correspond to the respective measurements of specimens collected from all over Poland, which were published byBERGER (1963).This corresoondence can be illustrated by drawing a comparison between the mean values and varlabllty ranges of three shell conchologlcal Characters of the population coming from Cracow (data given as Xk) and those of , where his shell height, w is shell width, and e Is shell elongation degree.The variability ranges of the characters, given by BERGER Shells of this species have been found In all samples of locality B. They have one easily discernible parietal tooth.The biometrical characters of a population of 41 specimens correspond to the respective dimensions of the species given by several authors (LOZEK 1956, URBANSKI Blomelrlclll ct.aderistcs of selected sn ... species.A, B -loalltles of lhe f-a. a -asymmetry Index, b -....,...., (big ._lllr),h -shell height, s -spire size Index, eshell elontallen defree 1957).The variabllly of size and shape ol the PtpiJ/1 musct¥111J shell was studied in detail by