ISSN 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 Shells
E. A. Snegin
*, A. A. Sychev
, and A. S. Shapovalov
Belgorod National Research University, ul. Pobedy 85, Belgorod, 308015 Russia
Belogorie State Nature Reserve, Monastyrskii per. 3, Borisovka, Belgorod oblast, 309342 Russia
Received April 22, 2015
Keywords: Holocene, steppe ecosystems, mollusks, repaired shells, ungulates
Reconstructions of environmental conditions of
the past epochs inevitably involves certain difficulties.
Paleoecologists in their research have to rely on indi-
cators indirectly characterizing the effects of factor of
different nature in the past. 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 stri-
ata Müller. This species belongs to the Mediterranean
group of relict xerophilic mollusks (Nikolaev, 1973;
Snegin, 202). Its present-day range includes western
and central Europe and the southern part of eastern
Europe 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 often
concentrate in relict plant communities. They have a
slightly compressed turbinate shell of medium size. In
the study region, its large diameter reaches 12–15 mm,
and height, 8–11 mm (Snegin, 2004; Snegin and
Sychev, 2011). Empty shells of dead snails accumulate
in their habitats over many years, which makes it pos-
sible to collect representative samples for analyzing
variation in conchological traits. Moreover, these shells
are well preserved in soil deposits and therefore can be
used to reconstruct paleoecological conditions in the
European Pleistocene and Holocene ecosystems
(Sparks, 1953; Lozek, 1964; Markovic et al., 2007).
In 2012, a soil pit was excavated at the mouth of
Veshnyaki ravine in the Yamskaya Step site of the
Belogorie State Nature Reserve ((51°10′31.26″ N,
37°37′30.28″ E). In the course of integrated analysis of
paleosols, 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 of
this 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 from
191.35 kg of soil. They included specimens with intra-
vital injuries that the mollusk could repair and con-
tinue growing (Sychev, 2013). In particular, these were
cracks resulting from accidental mechanical impact
(compression). Such shells were characterized by dif-
ferent orientation of riblet sculpture before and after
injury and deviations from the initial geometry and
growth direction. Similar injuries and disturbances
were also noted in recent shells.
In steppe ecosystems, ungulates are most likely to
be responsible for such injuries. The point is that the
shell of H. striata is thick-walled and fairly durable,
and cracks in it probably appeared after a blow with a
hard object, such as a hoof. According to available
data, injuries inflicted by small birds have a different
pattern, looking like local shearing cuts.
Predatory beetles and rodents feeding on snails
leave specific traces of gnawing through the shell from
the apertural side, which are sometimes difficult to
distinguish from accidental mechanical damage after
the death of the snail
(Fig. 3). Moreover, the proba-
bility of snail survival and shell repair after a targeted
attack by a predator is low.
Recent forest–steppe ecosystems of the study
region are permanently inhabited only by two wild
ungulate species, roe deer (Capreolus сapreolus) and
wild boar (Sus scrofa). However, some areas populated
by H. striata, are used for cattle grazing, and the
impact of cattle on herbaceous vegetation is similar to
Large birds usually ingest such snails together with the shell.
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 and
xerophilic meadows. This beetle gnaws through the shell with
the jaws, starting from the apertural side and reaching snail’s
soft tissues, but it can only cope with relatively thin shells of
young snails. However, it cannot be excluded that steppe ecosys-
tems in the past were inhabited by beetles of other species that
could overcome adult snails.