In this study we propose a method for estimating the impact of ungulates on Holocene steppe ecosystems by analyzing repaired injuries in fossil shells of the land snail Helicopsis striata Mülle

Shapovalov, A. S.

Snegin, E. A.

Sychev, A. A.

DSpace at Belgorod State University

514ISSN 1067-4136, Russian Journal of Ecology, 2016, Vol. 47, No. 5, pp. 514–517. © Pleiades Publishing, Ltd., 2016.Original Russian Text © E.A. Snegin, A.A. Sychev, A.S. Shapovalov, 2016, published in Ekologiya, 2016, No. 5, pp. 396–400.Estimating the Impact of Ungulates on Holocene Steppe Ecosystems by Analyzing Repaired Injuries in Land Snail ShellsE. A. Snegina, *, A. A. Sycheva, and A. S. ShapovalovbaBelgorod National Research University, ul. Pobedy 85, Belgorod, 308015 RussiabBelogorie State Nature Reserve, Monastyrskii per. 3, Borisovka, Belgorod oblast, 309342 Russia*e-mail: snegin@bsu.edu.ruReceived April 22, 2015Keywords: Holocene, steppe ecosystems, mollusks, repaired shells, ungulatesDOI: 10.1134/S1067413616050118Reconstructions of environmental conditions ofthe past epochs inevitably involves certain difficulties.Paleoecologists in their research have to rely on indi-cators indirectly characterizing the effects of factor ofdifferent nature in the past. In this study we propose amethod for estimating the impact of ungulates onHolocene steppe ecosystems by analyzing repairedinjuries in fossil shells of the land snail Helicopsis stri-ata Müller. This species belongs to the Mediterraneangroup of relict xerophilic mollusks (Nikolaev, 1973;Snegin, 202). Its present-day range includes westernand central Europe and the southern part of easternEurope to th Don River (Shileiko, 1978).Or studies were performed in the south of the Cen-tral Russian Plain, where these snails live on sun-warmed slopes of ravines with chalk soils and oftenconcentrate in relict plant communities. They have aslightly compressed turbinate shell of medium size. Inthe study region, its large diameter reaches 12–15 mm,and height, 8–11 mm (Snegin, 2004; Snegin andSychev, 2011). Empty shells of dead snails accumulatein their habitats over many years, which makes it pos-sible to collect representative samples for analyzingvariation in conchological traits. Moreover, these shellsare well preserved in soil deposits and therefore can beused to reconstruct paleoecological conditions in theEuropean Pleistocene and Holocene ecosystems(Sparks, 1953; Lozek, 1964; Markovic et al., 2007).In 2012, a soil pit was excavated at the mouth ofVeshnyaki ravine in the Yamskaya Step site of theBelogorie State Nature Reserve ((51°10′31.26″ N,37°37′30.28″ E). In the course of integrated analysis ofpaleosols, fragments of snail shells were collected,which concentrated in the 230- to 250-см horizon.Radiocarbon dating of soil humus in the Kiev Radio-carbon Laboratory (Ukraine) showed that the age ofthis horizon is 3290 ± 90 years (Ki-17953), which cor-responds to the late Subboreal period of the Holocene.A total of 34 H. striata shells were collected from191.35 kg of soil. They included specimens with intra-vital injuries that the mollusk could repair and con-tinue growing (Sychev, 2013). In particular, these werecracks resulting from accidental mechanical impact(compression). Such shells were characterized by dif-ferent orientation of riblet sculpture before and afterinjury and deviations from the initial geometry andgrowth direction. Similar injuries and disturbanceswere also noted in recent shells.In steppe ecosystems, ungulates are most likely tobe responsible for such injuries. The point is that theshell of H. striata is thick-walled and fairly durable,and cracks in it probably appeared after a blow with ahard object, such as a hoof. According to availabledata, injuries inflicted by small birds have a differentpattern, looking like local shearing cuts.1Predatory beetles and rodents feeding on snailsleave specific traces of gnawing through the shell fromthe apertural side, which are sometimes difficult todistinguish from accidental mechanical damage afterthe death of the snail2 (Fig. 3). Moreover, the proba-bility of snail survival and shell repair after a targetedattack by a predator is low.Recent forest–steppe ecosystems of the studyregion are permanently inhabited only by two wildungulate species, roe deer (Capreolus сapreolus) andwild boar (Sus scrofa). However, some areas populatedby H. striata, are used for cattle grazing, and theimpact of cattle on herbaceous vegetation is similar to1 Large birds usually ingest such snails together with the shell.2 The recent entomofauna of the study region includes one snail-eating ground beetle species, Licinus cassideus Fabricius, 1792(Carabidae), which lives mainly in steppificated biotopes andxerophilic meadows. This beetle gnaws through the shell withthe jaws, starting from the apertural side and reaching snail’ssoft tissues, but it can only cope with relatively thin shells ofyoung snails. However, it cannot be excluded that steppe ecosys-tems in the past were inhabited by beetles of other species thatcould overcome adult snails.SHORT COMMUNICATIONSRUSSIAN JOURNAL OF ECOLOGY  Vol. 47  No. 5  2016ESTIMATING THE IMPACT OF UNGULATES 515that of wild ungulates in the past. Therefore, we alsoestimated the frequency of intravitally damaged andrepaired shells in snails living in areas currently (oruntil recently) used for cattle grazing (Table 1, bio-topes 2 and 3) and in areas not exposed to this impact(biotopes 1 and 4).Comparisons of populations with respect to thefrequencies of shells with repaired injuries was per-formed using Fisher’s test (phi method) (Plokhinskii,1970).As follows from the results (Tables 1, 2), the fre-quency of snails with repaired shells proved to be sig-nificantly higher (p < 0.05) in biotope 2 (regularlygrazed) and biotope 3 (grazed until recently) than inungrazed biotopes 1 and 4. Comparison of popula-tions from biotopes 2 and 3 with th fossil group frombiotope 5 revealed no significant differences, which maybe regarded as evidence for a high grazing load on thesteppe ecosystems of the study region in the late Subbo-real period. According to historical data (Smirnova et al.,2001), the region during that period was inhabited by thetarpan (Equus ferus), onager (Equus hemionus), Euro-pean bison (Bison bonasus), aurochs (Bos primigenius),and saiga antelope (Saiga tatarica).It should also be taken into account that tribes ofthe Timber-grave, Bondarikhino, and Scythian cul-tures were living in the southern forest–steppe zone ofthe Central Russian Plain (including the study region)Table 1. Description of biotopes, samples sizes, and proportions of damaged H. striata shellsSamples were taken without regard to sampling area, and population density differed between the sites.Sampling site Coordinates Biotope, economic activities Numberof H. striata shellsProportionof damaged cells, %1. Gubkin 51°17′49.64″ N, 37°32′14.56″ EFeather grass steppe traveled by people and used for walking pets; no grazing 850 3.12. Telshovka 51°02′24.04″ N, 37°17′01.77″ EMixed grass steppe regularly grazed by cattle (about 500 head) 569 22.03. Protection zone 51°10′40.39″ N, 37°36′15.59″ EMixed grass steppe in the protection zone of Yamskaya Step reserve near abandoned summer cattle barn; no grazing since 2006 2006 г.147 7.54. Veshnyaki 51°10′36.10″ N, 37°37′32.62″ EFeather grass steppe in Yamskaya Step reserve, no grazing 25 0.05. Soil layer,age 3290 ± 90 years51°10′31.26″ N 37°37′30.28″ EVeshnyaki ravine in Yamskaya Step area of Belogorie reserve, soil pit 34 14.7Fig. 1. Fossil H. striata shells from horizon 230–250 cm with repaired injuries (arrows): (a) side view, (b) top view.(а)(b)516RUSSIAN JOURNAL OF ECOLOGY  Vol. 47  No. 5  2016SNEGIN et al.and the turn of the 2nd and 1st millennia BP, and live-stock breeding was a major form of their economicactivity (Shramko, 1962). Therefore, both wild anddomesticated ungulates could account for the highproportion of damaged H. striata shells in that period,with grazing impact leading to the formation of short-grass landscapes with sparse ground layer (Chendeevet al., 2014).Because of the long period of accumulation ofempty shells and low rate of their decomposition incarbonate environment, this method can be used forassessing population dynamics (changes in activity) ofungulates only on a long time scale. Using it for reveal-ing relatively fast changes in grazing load during in thepast epochs will be incorrect, because the shells sepa-rated in time by several decades can form mixed aggre-Fig. 2. Recent H. striata shells from Teleshovka population with repaired injuries (arrows): (a) side view, (b) top view.(а)(b)Fig. 3. Shells of H. striata damaged by (a) a bird and (a) a ground beetle.(a) (b)RUSSIAN JOURNAL OF ECOLOGY  Vol. 47  No. 5  2016ESTIMATING THE IMPACT OF UNGULATES 517gated on the soil surface or in upper soil horizons.Short-term changes in the abundance of ungulates canalso be studied by analyzing repaired injuries on theshells of living H. striata snails.Thus, the results presented above show that theproposed method can be used to reconstruct paleo-ecological conditions and evaluate grazing load onsteppe ecosystems. To test this method more thor-oughly, it appears expedient to increase the number oftest areas and broaden their geographic range.It should also be noted that the ability to quicklyrepair injuries in the shell can be regarded as an adap-tation to life in xerophilic communities and is alsocharacteristic of other steppe snails similar to H. striatain size, namely, Xeropicta krynickii, X. derbentina,Hellicela candicans, other species of this genus. Appar-ently, their shells can also be used in studies on recon-structing paleoecological conditions in the steppeecosystems of Eurasia,REFERENCESChendev, Yu.G., Ershova, E.G., Aleksandrovskii, A.L.,et al., Changes in the natural environment during the Holo-cene as inferred from integrated analysis of ravine deposits:The Yamskaya steppe, Mat-ly Vserosssiiskoi nauch. konf. poarkheologicheskomu pochvovedeniyu (Proc. All-RussiaConf. on Archaeological Soil Science), Pushchino, 2014,pp. 176–180.Ložek V. Quartärmolluscen der Tschechoslowakei, Roz-pravy Ustredniho Ustavu Geologického, 1964, vol. 31, p. 374.Markovic, S.B., Oches, E.A., McCoy, W.D., et al., Mala-cological and sedimentological evidence for ‘‘warm’’ glacialclimate from the Irig loess sequence, Vojvodina, Serbia,Geochem. Geophys. Geosyst., 2007, vol. 8, no. 9, pp. 1–12.Nikolaev, V.A., Land snails of the Central Russian Plain,Cand. Sci. (Biol.) Dissertation, Orel, 1973.Plokhinskii, N A., Biometriya (Biomety), Moscow: Mosk.Gos. Univ., 1970.Shileiko, A.A., Nazemnye mollyuski nadsemeistva Heli-coidea (Land Snails of the Superfamily Helicoidea), Lenin-grad: Nauka, 1978.Shramko, B.A., Drevnosti Severskogo Dontsa (Relics ofAncient Times from the Seversky Donets), Kharkov: Khar-kov. Gos. Univ., 1962.Smirnova, O.V., Turubanova, S.A., Bobrovskii, M.V., et al.,Reconstruction of the history of the East European forestzone and the problem of maintaining biological diversity,Usp. Sovrem. Biol., 2001, vol. 121, no. 2, pp. 144–159.Snegin, E.A., Using land snail species as indicators of relictcenoses, Vestn. Zhitomir. Ped. Univ., 2002, no. 10, pp. 128–129.Snegin, E.A., The striped heath snail Helicopsis striataMüll., in Krasnaya kniga Belgorodskoi oblasti. Redkie iischezayushchie rasteniya, griby, lishainiki i zhivotnye. (TheRed Data Book of Belgorod Oblast: Rare and EndangeredPlants, Fungi, Lichens, and Animals), Prisnii, A.V., Ed.,Belgorod, 2004.Snegin, E.A. and Sychev, A.A., Assessing the viability ofpopulations of specially protected species Helicopsis striataMüller (Mollusca, Gastropoda, Pulmonata) in the south ofthe Central Russian Plain, Teor. Prikl. Ekol., 2014, no. 2,pp. 83–92.Sparks, B.W., The former occurrence of both Helicella stri-ata (Müller) and H. geyeri (Soós) in England, J. Conchol.,1953, vol. 23, pp. 372–378.Sychev, A.A., On reconstruction of paleoconditions in theforest–steppe of the Central Russian Plain based on thelevel of variation in shell-bearing mollusks, Bioraznoobra-zie: global’nye i regional’nye protsessy: Mat-ly vseros. konf.molodykh uchenykh (Biodiversity: Global and RegionalProcesses, Proc. All-Russia Young Scientists Conf.), Ulan-Ude: Buryat. Nauch. Tsentr Ross. Akad. Nauk, 2013,pp. 167–169.Translated by N. GorgolyukTable 2. Values of Fisher test obtained in comparison of pop-ulation frequencies of H. striata shells with repaired injuries.Underlined values are statistically significant at p < 0.05)Population 1 2 3 4 512 131.93 5.0 20.84 3.0 22.8 15.75 5.9 1.2 1.4 8.7

Estimating the impact of ungulates on holocene steppe ecosystems  by analyzing repaired injuries in land snail shells

http://dspace.bsu.edu.ru/bitstream/123456789/18252/1/Snegin%20E.A._Estimating_16.pdf

Estimating the impact of ungulates on holocene steppe ecosystems by analyzing repaired injuries in land snail shells

Abstract

Similar works

Full text

Available Versions

DSpace at Belgorod State University