Russian Entomol. J. 21(2): 169–178 © RUSSIAN ENTOMOLOGICAL JOURNAL, 2012

How many forest and steppe ground and darkling beetles (Coleoptera: Carabidae, Tenebrionidae) are there in West Siberian faunal assemblages?

Ñêîëüêî ëåñíûõ è ñòåïíûõ æóæåëèö è ÷åðíîòåëîê (Coleoptera: Carabidae, Tenebrionidae) â ñîîáùåñòâàõ çàïàäíî-ñèáèðñêîé ëåñîñòåïè?

V.G. Mordkovich Â.Ã. Ìîðäêîâè÷

Institute of Systematics and Ecology of Animals, Siberian Branch of the Russian Academy of Sciences, Frunze 11, Novosibirsk, 630091, Russia. Èíñòèòóò ñèñòåìàòèêè è ýêîëîãèè æèâîòíûõ ÑÎ ÐÀÍ, óë. Ôðóíçå 11, Íîâîñèáèðñê 630091, Ðîññèÿ.

KEY WORDS: forest-steppe zone, taiga, steppe, tree stand, grass stand, West Siberian Plain, beetles, ecological spectrum, community, species richness, abundance. ÊËÞ×ÅÂÛÅ ÑËÎÂÀ: ëåñîñòåïü, òàéãà, ñòåïü, äðåâîñòîé, òðàâîñòîé, Çàïàäíî-Ñèáèðñêàÿ ðàâíèíà, æóêè, ýêîëîãè÷åñêèé ñïåêòð, ñîîáùåñòâî, âèäîâîå áîãàòñòâî, ÷èñëåííîñòü.

ABSTRACT: Zoodiversity of the forest-steppe zone ÐÅÇÞÌÅ: Çîîðàçíîîáðàçèå ëåñîñòåïíîé çîíû is commonly believed to be resultant of the forest and îáû÷íî ñ÷èòàåòñÿ ñìåñüþ ëåñíîé è ñòåïíîé áèîò. steppe faunas mixture. According to this notion, the Ñîãëàñíî ýòîé âåðñèè îæèäàåòñÿ, â ñâåòå ãðÿäóùå- further climate warming is expected to shift the bal- ãî ïîòåïëåíèÿ, ñìåùåíèå áàëàíñà ëåñíûõ è ñòåï- ance between the forest and steppe biotic components íûõ ýëåìåíòîâ áèîòû â ïîëüçó áîëåå àðèäíûõ. Ïî towards more aridophilous ones. Many years of terres- èòîãàì ìíîãîëåòíèõ èññëåäîâàíèé íàïî÷âåííûõ trial beetles investigation revealed that their forest- æóêîâ âûÿñíèëîñü, ÷òî ñðåäè îáèòàòåëåé ëåñîñòå- steppe assemblages are dominated by species with po- ïè ïðåîáëàäàþò âèäû ñ ïîëèçîíàëüíûìè àðåàëàìè, lyzonal areas, but having maximal density populations íî èìåþùèå ïîïóëÿöèè ñ ìàêñèìàëüíîé ïëîòíîñ- in the forest-steppe zone. Proportion of species with òüþ â çîíå ëåñîñòåïè. Äîëÿ âèäîâ ñ ïðåèìóùåñòâåí- mostly forest and steppe metapopulations does not ex- íî ëåñíûìè è ñòåïíûìè ìåòàïîïóëÿöèÿìè íå ïðå- ceed summarily 30%. The forest-steppe terrestrial bee- âûøàåò â ëåñîñòåïè, ñóììàðíî, 30%. Ëåñîñòåïíûå tle assemblages displayed specific ecological group ñîîáùåñòâà íàïî÷âåííûõ æóêîâ îòëè÷àþòñÿ ñïå- structure dominated by species preferring meadow hab- öèôè÷åñêîé ñòðóêòóðîé äîìèíèðîâàíèÿ â ñïåêòðå itats. Analysis of beetle faunal assemblages’ similarity ýêîãðóïï âèäîâ, ïðåäïî÷èòàþùèõ êîëè÷åñòâåííî in respect to ecological group dominance structure re- ëóãîâûå ìåñòîîáèòàíèÿ. Àíàëèç ñòåïåíè ðàçëè÷èÿ vealed four series of phylogenesis in the forest-steppe. ñîîáùåñòâ ïî ñòðóêòóðå äîìèíèðîâàíèÿ ýêîãðóïï Each series begins from the transformation of different âûÿâèë íàëè÷èå ÷åòûðåõ ñåðèé ôèëîãåíåçà â ëåñî- archetype coenoses, apparently inherited from the peri- ñòåïè. Êàæäàÿ èç íèõ íà÷èíàåòñÿ ñ ïðåîáðàçîâàíèÿ glacial savanna of the last Glacial period, namely peat- ðàçíûõ öåíîçîâ-àðõåòèïîâ, óíàñëåäîâàííûõ, âèäè- lands, park forests, halocoenoses and dry meadows. In ìî, îò ïåðèãëÿöèàëüíîé ñàâàííû ïðåäøåñòâîâàâøå- course of succession all these coenoses are transformed ãî ëåäíèêîâüÿ — òîðôÿíûõ áîëîò, ëåñîïàðêîâ, ãàëî- into a single reference one, i.e. meadow coenosis. Bee- öåíîçîâ è ñóõèõ ëóãîâ. Âñå îíè â õîäå ñóêöåññèé tle faunal assemblages in the forest-steppe are charac- ïðåâðàùàþòñÿ öåíòðîñòðåìèòåëüíî â åäèíûé ýòà- terized by the most original and dynamically stable ëîí — ëóãîâîé öåíîç. Ëóãîâûå ñîîáùåñòâà â ëåñî- composition and structure, occupying more than 70% ñòåïè îòëè÷àþòñÿ íàèáîëåå îðèãèíàëüíûì è óñòîé- of the zonal area with a wide range of habitats. There- ÷èâûì â äèíàìèêå ñîñòàâîì è ñòðóêòóðîé, çàíèìàþò fore the meadow coenoses, rather than the fragmentary áîëåå 70% ïëîùàäè çîíû â øèðîêîì äèàïàçîíå ìåñ- quasi-steppes and forest-like insular tree stands, repre- òîîáèòàíèé. Ïîýòîìó èìåííî îíè, à íå ôðàãìåíòàð- sent the indigenous element of the latitudal zone be- íûå êâàçèñòåïè è ëåñîïîäîáíûå êîëêè ïðåäñòàâëÿ- tween taiga and steppe. It makes more sense to refer to þò êîðåííîé ýëåìåíò øèðîòíîé çîíû ìåæäó òàéãîé the corresponding original biome as a meadow, rather è ñòåïüþ. Ñîîòâåòñòâóþùåé åé îðèãèíàëüíûé áèîì than steppe, one. ëîãè÷íåå èìåíîâàòü ëóãîâûì, à íå ëåñîñòåïüþ. 170 V.G. Mordkovich

Introduction Ecological criteria enable to answer the question to what degree the composition and structure of insect Landscape ecology of pedobionts has always at- faunal assemblages of the forest steppe tree and grass tracted significant attention of soil zoologists, such as stands resembles the reference forest and steppe as- M.S. Ghilarov [1965] and his immediate followers, semblages. The issue becomes increasingly actual in including B.R. Striganova. The book about pedobiont respect to the global warming, which is often identified assemblages and their structure in the latitudal zones of with aridisation. In fact the global warming is quite a the West Siberian Plain is the most recent major gener- controversial phenomenon, and in different regions of alization in the field [Striganova, Poryadina, 2005]. the world may result either in aridisation or humidifi- In the system of those latitudal zones of particular cation of the environment. Judging by the meteorologi- interest is the forest-steppe zone as it is generally char- cal data of the recent decades, in the forest-steppe zone acterized as a marginal mosaic complex of biota at the of the West Siberian Plain the global warming appar- interface of forest and steppe. The latitudes occupied ently results in the drastic intensification of annual and by the forest-steppe display some extraordinary fea- seasonal climatic fluctuations [Beresneva, 2006], the tures in the gradient of environmental conditions from latter being quite pronounced even without any warm- the Equator to the Northern Pole: the broadest environ- ing. mental conditions range, the balance between evapora- Under such environmental conditions the assem- tion and precipitation, the balance between soil humifi- bling of insect species into the forest-steppe communi- cation and mineralization and very high natural soil ties, presumably, should be directed against the organ- fertility, etc. Thanks to all these the forest-steppe may isms with narrow specialization to hyper-humid or su- be regarded as a zone of environmental comfort for per-arid conditions, favouring the species that are tol- biota. As a result, species richness along the latitudal erant to a broad environmental range. To test this hy- gradient reaches its maximum in the forest-steppe. The pothesis we analyzed the taxonomical composition and total biodiversity of arthropods, comprising 90% of the ecological structure of a) predator ground beetles as- total fauna biodiversity, amounts to 4,000 species, that semblages, that are abundant and diverse in the forest, is 1.5–2.0 times higher than in the neighbouring forest forest-steppe and steppe zones, and b) sapro-and phy- and steppe zones [Mordkovich et al., 2002]. tophagous darkling beetles as most of them, excepting What is the mechanism causing such a high rate of forest and water-dwelling species, are considered to be species richness? The most common concept tends to indicative of aridisation. attribute the latter to the result of a mere summation in the forest-steppe zone of all the species expanding Materials and methods from the north and from the south. Areal analysis seems to confirm this view as no less than 80% of the forest- The study region. The study was carried out in the steppe biota species, and primarily insects, enjoy po- Plains in the south of West Siberia, Russia (Baraba and lyzonal areas, embracing forest-steppe and forest zones Kulunda) and in Central Kazakhstan (Atbasar, Tengiz or forest-steppe and steppe zones, or even all three and Balkhash Plains, Kazakhstan) in the geographical ones. The major issue here is that there are few reasons region within 65–44°N and 70–80°E, embracing 3 taiga to consider such species as truly autochtonous forest- subzones (the northern, middle and southern ones), 3 steppe ones, intruding to the north and south, and vice forest-steppe subzones (northern, typical and southern versa. ones) and 3 steppe subzones (arid-chernozemic, The occurrence of endemic species can serve as an kastanozemic dry and deserted ones), as well as in the objective criterion for fauna’s specificity. There are northern subzone of the temperate desert (Cis- and endemic species in the forest-steppe zone. Analyzing Trans-Balkhash areas). A typical catena with represen- the ground beetles and other insects’ faunas in the East tative ecosystems (eluvial, EL, transit, TR, and accu- European forest-steppe, K.V. Arnoldi [1965] observed mulative, AC) were chosen. Typical zonal biogeo- dozens of endemic species. According to Siberian en- coenoses that had never been ploughed, regularly hayed, tomologists, the degree of endemism for the West Si- overgrazed or otherwise subjected to anthropogenic berian forest-steppe fauna ranges from 1–2 to 10–15% land use impact were chosen as reference ecosystems. for various taxa [Mordkovich et al., 2002]. Nonethe- Beetle sampling. Ground beetles (Coleoptera: Cara- less, arealogical argumentation is not sufficient to infer bidae) and darkling beetles (Coleoptera: Tenebrion- the indigenous character of the forest-steppe entomo- idae) were samples using pitfall traps of 12 cm diame- logical assemblage. ter. Ten traps were placed at each site. Trapping was Alongside with the size and contour of the area of conducted monthly since May till August during con- crucial importance is the structure of its so called “en- secutive 2–3 years at each study site, i.e. on the chosen vironmental lace”. The term refers to the number and catena in each latitudal zone and subzones. Traps were structure of habitats, occupied by certain biological operated for 5 ´ 24 h at each study site, with the species. In such case species quantitative characteris- captured individuals removed and later processed in tics and metapopulation architectonics are taken into the laboratory and separated to species. The data used account [Khanski, 2010]. for further analyses represent the sum of individuals Beetles in the west-siberian steppes 171 over 4 seasonal countings in each biotope for 100 trap- est-steppe and the riverside forest in the Siberian south- days (10 traps * 20 days). ern taiga was 25%. Species composition of the insular The study yielded more than 200 ground beetle tree stands of the West-Siberian forest-steppe and oak species and 17 darkling beetle species. Therefore the stands of the East-European forest-steppe was estimat- list of genera and species is not comprehensive of the ed to be slightly higher (25–30%), but only due to non- biodiversity of ground beetles and darkling beetles fau- specialized hydrophilous species: Pterostichus nigrita nas of the studied region, but includes only those fau- (Paykull, 1790), Pt. vernalis (Panzer, 1795), Platynus nal components, that played the major role in shaping assimilis (Paykull, 1790), Elaphrus cupreus beetle assemblages. (Duftschmid, 1812). To compare beetle assemblages we used the fol- The taxonomical similarity of the ground beetle lowing index of difference: assemblages between the forest-steppe meadows and different arid and dry steppes did not exceed 30 and n n ñ = Ó á1 - á2 Ö(Ó á1 + Ó á2 ), 20%, respectively. We did not find species that were k k k k k=1 k=1 k=1 common for the faunas of the forest-steppe and desert- ed steppe. where á1 and á2 are numbers of a certain species (k) k k The similarity of darkling beetles faunas between in the 1st and 2nd communities, respectively, while Sá1 k the forest-steppe and steppe zones was higher than that and Sá2 are the sums of species numbers from the 1 to k of the ground beetles, but likewise did not exceed 50%. st nd the n species of the 1 and 2 communities, respectively. The highest values of the Jaccard index were calculat- To compare faunal assemblages we also used the ed between the local faunas of the meadow steppe and biological diversity index, calculated as M = a/vb, where stepped meadow in the forest-steppe zone, on one hand, a stands for the total number of species, and b is the and between solonetz steppe meadows of transit eco- total number of insects in the community [Magurran, systems in the steppe zone, on the other hand, most 1992]. likely due to the increased moisture because of the lateral soil water flow. Results In general the comparison of ground beetle and darkling beetle species richness did not provide rea- In the forest-steppe zone and chernozemic subzone sons to consider the forest-steppe fauna a continuation of the steppe zone the ground beetle species richness in or at least a derivative of the steppe fauna, showing its the studied catena biotopes (EL + TR + AC) reached independent character. 90–92 species. In the dry kastanozem steppes the ground beetle species richness decreased almost 2-fold (58 Ecological characteristics of species species), and still farther to the south decreased to just Taxocoenes of zoophagous and mixophagous 28 species in the deserted steppe. ground beetles and saprophytophagous darkling bee- Latitudally, the number of the ground beetle genera tles occupy different trophical niches, however, their decreased less seriously, from 23–24 genera to 16–19 biotopical preferences coincide. Because of this, to per catena. compare these taxocoenes, we chose ecological groups, The darkling beetle fauna displayed quite the oppo- determined a priori according to the species popula- site pattern of species richness changes from north to tion distributions in relation to a single standardized south, as the number of their species increased from zonal catena matrix of habitats. Ecological groups are just 5 species in the grass stands of the forest-steppe to composed on the basis of selective attitude of different 8–9 species in the chernozemic and kastanozem steppe insect species in the geographic and ecographic space zones and farther to the south up to 12 species in the of limiting environmental factors, i.e. temperature, deserted steppe subzone. The number of ground beetle moisture, substrate texture, vegetation cover (Table genera increased from 4 in the forest-steppe to 8 gen- 1). The general principles of ecological groups typolo- era in the steppe and 10 in the deserted steppe sub- gy were explained in detail earlier [Mordkovich, zones. Lubechanskii, 2010; Mordkovich, 2011]. Below we The similarity index between the ground beetle fau- provide the revised sets of ecological groups that are nas of the insular tree stands of the West-Siberian characteristic for the West Siberia and Central Kazakh- forest-steppe and zonal forests of the West Siberia and stan ecosystems, as well as ground beetle and darkling East Europe was not high. For instance, the commu- beetle species comprising each group. nality of ground beetle faunal composition between the Forest cryohygrophiles (FCH). These beetles had park forest of the forest-steppe and zonal southern maximal abundance in the mired tree stands of the TR taiga in the West Siberia did not exceed 19%. The and AC taiga catena ecosystems, but were also com- ground beetle faunas similarity between the hydromor- mon, albeit less abundant, in the grass wetlands of the phic forest-steppe insular tree stands and zonal south- forest-steppe. FCH are represented mostly by the ground ern or middle taiga was not higher than 13%, whereas beetles: Notiophilus reitteri (Spaeth, 1900), Leistus ter- the ground beetle faunas similarity between the semi- minatus (Hellwig, 1793), Patrobus septentrionis (De- hydromorphic insular tree stands of the northern for- jean, 1828), Platynus mannerheimi (Dejean, 1828), 172 V.G. Mordkovich

Table 1. Hierarchal classification of ground beetle topoecotypes of the West Siberian and Central Kazakhstan plains in re- lation to habitat insolation, total moisture and plant ecobiomorphs, dominating in coenoses.

Insolation intensity and Environment moisture rate and Phytocoenoses with dominating plant regime preferred regime preferred ecobiomorphs preferred Shrubs

Hygrophiles Grass

Mosses and lichens Eucryophiles Shrubs

Mesophiles Grass

Mosses

Hygrophiles Grass Semicryophiles Mesophiles Forest

Tugai-forest

Hygrophiles Tugai-grass

Ardophiles Euphemroides

Grass Xerophiles Shrubs

Xerophiles

Thermophiles Mesophiles Shrubs

Hygrophiles Grass

Grass Psychrophiles Hygrophiles Forest

Sericoda quadripunctata (De Geer, 1774), Curtonotus rita (Paykull, 1790), P. gracilis (Dejean, 1828) and gebleri (Dejean, 1831), Bembidion gilvipes (Sturm, others. 1825), Badister peltatus (Panzer, 1796), Trachypachis Grass cryomesophiles (GCM). This group showed zetterstedti (Gyllenhal, 1810). maximal abundance in the standing grass of the taiga Grass cryohygrophiles (GCH). These insects showed TR ecosystems, and its major components were the maximal abundance in the grass AC wetland ecosys- ground beetles: Amara aenea (De Geer, 1774), A. bi- tems of taiga catenas and are represented mostly by frons (Gyllenhal, 1810), A. consularis (Duftschmid, Acupalpus dorsalis (Fabricius, 1787), Agonum dolens 1812), A. praetermissa (Sahlberg, 1827), A. quenseli (Sahlberg, 1827), A. impressum (Panzer, 1796), A. liv- (Schonherr, 1806), Badister bullatus (Schrank, 1798), ens (Gyllenhal, 1810), A. longiventre (Mannerheim, Cicindela silvatica (Linnaeus, 1758), Clivina fossor 1825), A. piceum (Linnaeus, 1758), Amara erratica (Linnaeus, 1758), Curtonotus alpinus (Paykull, 1790), (Duftschmid, 1812), A. interstitialis (Dejean, 1828), Harpalus solitaris (Duftschmid, 1812). Blethisa multipunctata (Linnaeus, 1758), Chlaenius tris- Forest psychrohygrophiles (FPH). This group dis- tis (Schaller, 1783), Nebria livida (Linnaeus, 1758), played maximal abundance in the mired tree stands of Pelophila borealis (Paykull, 1790), Pterostichus nig- the forest-steppe AC ecosystems, being represented Beetles in the west-siberian steppes 173 mostly by the ground beetles: Pterostichus diligens (Linnaeus, 1758), Lebia cruxmior (Linnaeus, 1758); (Sturm, 1824), Platynus assimile (Paykull, 1790), Ag- and darkling beetles such as: Crypticus quisquilius (Lin- onum fuliginosum (Panzer, 1809), A. krynickii (Sperk, naeus, 1760), Opatrium riparium (Scriba, 1865). 1835), A. thorey (Dejean, 1828), Badister bipustulatus Grass psychrobalancephiles (GPB). This group (Fabricius, 1792), B. laecertosus (Sturm, 1815), Cara- reached maximal abundance in the EL grass stands of bus granulatus (Linnaeus, 1758), C. violaceus (Lin- the forest-steppe and chernozemic steppe catenas and naeus, 1758), Oodes helopioides (Fabricius, 1792). was represented by the ground beetles Agonum muel- Forest psychromesophiles (FPM). These beetles leri (Herbst, 1784), Poecilus fortipes (Chaudoir, 1850), reached maximal abundance in the tree stands of the P. lepidus (Leske, 1785), P. sericeus (Fischer von Wald- forest-steppe EL and TR ecosystems, including mostly heim, 1824), Harpalus smaragdinus (Duftschmid, the following ground beetles: Agonum lugens (Duft- 1812), H. calceatus (Duftschmid, 1812), H. froelichi schmid, 1812), A. brunnea (Gyllenhal, 1810), A. com- (Sturm, 1818), H. pusillus (Motschulsky, 1850), H. munis (Panzer, 1797), Amara majuscula (Chaudoir, brevis (Motschulsky, 1844), H. anxius (Duftschmid, 1850), Carabus convexus (Fabricius, 1775), C. glabra- 1812), H. politus (Dejean, 1829), Dyschirius rufipes tus (Paykull, 1790), C. marginalis (Fabricius, 1794), (Dejean, 1825), Ophonus diffinis (Dejean, 1829), Syn- C. sibiricus (Fischer von Waldheim, 1820), Calathus tomus truncatellus (Linnaeus, 1761), Cicindela graci- melanocepalus (Linnaeus, 1758), Synuchus nivalis lis (Pallas, 1775), C. germanica (Linnaeus, 1758), as (Panzer, 1797), Notiophilus palustris (Duftschmid, well as darkling beetles: Pedinus femoralis (Linnaeus, 1812), N. germinyi (Fauvel, 1863), Harpalus latus (Lin- 1767), Opatrum sabulosum (Linnaeus, 1761), Blaps naeus, 1758), H. cisteloides (Motschulsky, 1844), H. lethifera Marsham, 1802. pumilus (Sturm, 1818), Licinus depressus (Paykull, Grass thermomesophiles (GTM). These insects dis- 1790), Panagaeus cruxmajor (Linnaeus, 1758), Poeci- played maximal abundance in the TR ecosystems grass lus versicolor (Sturm, 1824), Pterostichus melanarius stands of the forest-steppe and steppe catenas and were (Illiger, 1798), P. oblongopunctatus (Fabricius, 1787), represented by the ground beetles: Bembidion lampros Rhopalostyla virgata (Motschulsky, 1844). (Herbst, 1784), B. femoratum (Sturm, 1825), Poecilus Grass psychrohygrophiles (GPH). This group was punctulatus (Schaller, 1783), Pterostichus gyrosus (Mo- tschulsky, 1866), P. macer (Marsham, 1802), Amara found to reach maximal abundance in the forest-steppe apricara (Paykull, 1790), A. tibialis (Paykull, 1798), grass wetlands and was comprised primarily of the Curtonotus convexiusculus (Marsham, 1802), C. cribri- ground beetles: Agonum versutum (Sturm, 1824), A. collis (Chaudoir, 1846), Harpalus fuscipalpis (Sturm, viduum (Panzer, 1797), Amara famelica (Zimmermann, 1818), Polystichus connexus (Fourcroy, 1785), Cymin- 1831), A. nitida (Sturm, 1825), Bembidion assimile dis angularis (Gyllenhal, 1810), C. cylindrica Mo- (Gyllenhal, 1810), B. biguttatum (Fabricius, 1779), B. tschulsky, 1844, Microlestes minutulus (Goeze, 1777), guttula (Fabricius, 1792), Carabus clathratus (Linnae- Dyschirius globosus (Herbst, 1784), Calosoma denti- us, 1761), C. maeander (Fischer von Waldheim, 1822), colle (Gebler, 1833), as well as some darkling beetles — Chlaenius nigricornis (Fabricius, 1787), Ch. costula- Gonocephalum pusillum (Fabricius, 1792). tus (Motschulsky, 1859), Dametrias monostigma (Sa- Grass thermohygrophiles (GTH). The group was mouelle, 1819), Dromius ruficollis (Motschulsky, found to have maximal abundance in the waterlogged 1844), Dyschirius strumosus (Dejean, 1825), Elaphrus AC ecosystems of steppe catenas and was comprised cupreus (Duftschmidt, 1812), E. sibiricus (Motschul- mostly of the ground beetles Bradycellus collaris sky, 1844), Loricera pilicornis (Fabricius, 1775), Pa- (Paykull, 1798), Blethisa estsholtzi (Zoubkoff, 1829), trobus assimilis (Chaudoir, 1844), Pterostichus aterri- Harpalus oblitus (LeConte, 1859), Amara tricuspidata mus (Herbst, 1784), P. cursor (Dejean, 1828), P. mi- (Dejean, 1831), Bembidion fumigatus (Duftschmid, nor (Gyllenhal, 1827), P. vernalis (Panzer, 1795), Tre- 1812), B. octomaculatum (Goeze 1777), Calosoma au- chus rivularis (Gyllenhal, 1810), Trichocellus cogna- ropunctatum (Herbst, 1784), Poecilus cupreus (Lin- tus (Gyllenhal, 1827). naeus, 1758), P. lissoderus (Chaudoir, 1876), Chlae- Grass psychromesophiles (GPM). The group had nius spoliatus (Rossi, 1790). maximal abundance in the forest-steppe TR grass stands Grass thermoxerophiles (GTX). These insets pre- and was represented by the ground beetles: Amara ferred EL grass stands of the dry steppe subzone of equestris (Duftschmid, 1812: 109), A. similata (Gyllen- steppe zone and were represented by the ground bee- hal, 1810), A. ovata (Fabricius, 1792), A. infima (Duft- tles Carabus bessarabicus (Fischer von Waldheim, schmid, 1812), A. plebeja (Gyllenhal, 1810), Bembidi- 1823), Poecilus crenuliger (Chaudoir, 1876), Amara on quadrimaculatum (Linnaeus, 1761), Cicindela cam- timida (Motschulsky, 1844), Ophonus puncticollis pestris (Linnaeus, 1758), C. chiloleuca (Fischer von (Paykull, 1798), Harpalus hirtipes (Panzer, 1796), H. Waldheim, 1820), Curtonotus torridus (Panzer, 1796), optabilis (Dejean, 1829), H. brevis Motschulsky, 1844, C. aulicus (Panzer, 1796), Calathus erratus (C.R. Sahl- Taphoxenus tilesii (Fischer von Waldheim, 1823), T. berg, 1827), Callistus lunatus (Fabricius, 1775), Cara- gigas (Fischer von Waldheim, 1823), as well as some bus tuberculosus (Dejean, 1829), Harpalus affinis darkling beetles: Tenthyria nomas (Pallas, 1781), Platy- (Schrank, 1781), H. kirgisicus Motschulsky, 1844, H. scelis hypolitha (Pallas, 1781), Blaps halophila (Fis- subcylindricus (Dejean, 1829), Notiophilus aquaticus cher von Waldheim, 1822). 174 V.G. Mordkovich

Grass ardoxerophiles (GAX). They preferred de- steppe zones had a different combination of ecological serted steppes of the EL positions in the deserted steppe groups, dominated by forest psychromesophiles (48– subzone of steppe zone and are represented by the 85%). The proportion of forest xeromesophiles was ground beetles Harpalus caspius (Steven, 1806), H. shown to reach 18% only in the insular tree stands of salinus (Dejean, 1829), H. calathoides (Motschulsky, the northern forest-steppe, being hardly significant (1– 1844), Cymindis variolosa (Fabricius, 1794), C. deco- 2%) more southward. Specific ecogroup structures were ra (Fischer von Waldheim, 1829), Pseudotaphoxenus observed in the assemblages of the hydromorphic insu- rufitarsis (Fischer von Waldheim, 1823), as well as lar forests, flooded in spring by melting snow. In those some darkling beetles: Platyscelis picipes (Gebler 1833), biotopes forest psychrohygrophiles accounted for 51%. Blaps grandulata (Gebler 1825), Anatolica lata (Steven, Alongside with them, quite significant (21%) contribu- 1829). tion was made by forest cryohygrophiles. Grass ardohygrophiles (GAH). The beetles from Thus beetle faunal assemblages in all three types of this group were found to prefer saline mires of the AC the forest-steppe tree stands were quite different in ecosystems in the deserted steppe subzone and were their ecological group structure from those in the taiga represented by the ground beetles: Bembidion tenellum zone, where the natural forests were shown to be dom- (Erichson, 1837), Agonum viridicupreum (Goeze, inated by forest cryomesophiles, while the terrace insu- 1777), Poecilus subcoeruleus (Quensel, 1806), Opho- lar forests were dominated by forest cryo- and psychro- nus steveni (Dejean, 1825), O. rufibarbis (Fabricius, philes in equal proportions. The insular forest tree stands 1792), Microlestes plagiatus (Duftschmid, 1812), Cy- of the West-Siberian Plain were dominated by forest mindis picta (Pallas, 1771), Brachinus explodens psychroxeromesophiles and psychromesophiles. (Duftschmid, 1812), Elaphrus aureus (Muller, 1821), The West Siberian forest-steppe tree stands showed Poecilus cupreus (Linnaeus, 1758), as well as some much less difference between each other in beetle fau- darkling beetles: Crypticus zuberi (Marseul, 1869), Oo- na species composition and abundance, than with fau- descelis similes (Kaszab, 1938), Belopus procerus (Mul- nas of the taiga zone. sant, 1854), B. filiformis (Motschulsky, 1872). Comparison of ecological group assemblages of the taiga and forest-steppe zone by using the Pogozhev’s Community structure index with a fixed increment from 0 to 1 showed that 3 The proportion of beetles belonging to different subsets of the ground beetle taxocoenes could be dis- ecological groups was found to be specific for the tinguished: taxocoenes of the a) climax taiga with the forest-steppe tree stand faunas. For instance, the ground index not exceeding 0.2; b) forest-steppe insular tree beetle fauna of the park forest was characterized by stands with the index of 0.2–0.5; and c) mired taiga and almost equal proportions of forest psychroxerophiles forest-steppe tree stands with the index of difference and psychromesophiles (42 and 37%, respectively) between themselves of 0.4. The index of difference with13% of the forest cryomesophiles. The ground among these 3 subsets in no less than 0.8, which can be beetle taxocoenes of the semihydromorphic insular for- regarded as evidence of their different origin and sub- ests of the northern and southern forest-steppe and sequent genesis (Fig. 1).

Figure 1. The dissimilarity index of the ground beetles taxocoenes of the tree stands in the forest, forest-steppe and steppe zones of the West Siberian Plain. The habitats: 1 — swamped insular birch forest, 2 — semihydromorphic insular birch forest in the northern forest- steppe, 3 — semihydromorphic insular birch forest in the southern forest-steppe, 4 — semihydromorphic insular birch forest in the dry steppe, 5 — park birch forest in the forest-steppe, 6 — West-Siberian northern taiga, 7 — West-Siberian middle taiga, 8 — West-Siberian swamped middle taiga, 9 — West-Siberian southern taiga, and 10 — West-Siberian riverside southern taiga. Ðèñóíîê 1. Èíäåêñ ðàçëè÷èÿ òàêñîöåíîâ æóæåëèö äðåâîñòîåâ ëåñíîé, ëåñîñòåïíîé è ñòåïíîé çîí Çàïàäíî-Ñèáèðñêîé ðàâíè- íû. Òàêñîöåíû èç: 1 — çàáîëî÷åííîãî áåðåçîâîãî êîëêà, 2 — ïîëóãèäðîìîðôíîãî áåðåçîâîãî êîëêà â ñåâåðíîé ëåñîñòåïè, 3 — ïîëóãèäðîìîðôíîãî áåðåçîâîãî êîëêà â þæíîé ëåñîñòåïè, 4 — ïîëóãèäðîìîðôíîãî áåðåçîâîãî êîëêà â çîíå ñóõîé ñòåïè, 5 — ïàðêîâîãî áåðåçíÿêà â ëåñîñòåïè, 6 — çàïàäíîñèáèðñêîé ñåâåðíîé òàéãè, 7 — çàïàäíîñèáèðñêîé ñðåäíåé òàéãè, 8 — çàïàäíîñè- áèðñêîé çàáîëî÷åííîé ñðåäíåé òàéãè, 9 — çàïàäíîñèáèðñêîé þæíîé òàéãè, è 10 — çàïàäíîñèáèðñêîé ïðèðå÷íîé þæíîé òàéãè. Beetles in the west-siberian steppes 175

In the forest-steppe psychrophiles were found to changing according to hydrothermal or hydrochemical dominate the ground and darkling beetle assemblages fluctuations in the environment. of the mesophytic and stepped meadows, as well as For example, the ground beetle assemblages of the tree stands, both in species composition and abundance wet meadows were almost equally dominated by grass (not less than 80%). Cryohygrophiles could be found and forest psychromesophiles (31 and 26%, respec- only in the mires and wet meadows, and even there tively) and grass psychrohygrophiles. The ground bee- they contributed not more than 30% into the ecological tle assemblages of the mesohalophytic meadow on so- group structure. Thermomesophiles accounted for less lonetz had grass psychromesophiles and thermomeso- than 5% in the mesophytic meadows, whereas ther- philes contributing nearly the same proportions (42 moxerophiles accounted for not more than 30% in the and 48%, resp.), most likely because of the specific meadow steppes. properties of the solonetz horizon in the middle of the The ground and darkling beetle assemblages of the profile and very good thermoconductivity of the upper grass habitats in the forest-steppe of the West Siberia solonetz horizon. At the same time 98% the darkling were shown to be composed of species and individuals beetle assemblages of the halomesophytic solonetz from several ecological groups, represented in differ- meadow belonged to the psychromesophiles, rather than ent proportions. Some habitats had a pronounced dom- thermomesophiles or thermoxerophiles. The middle inance of beetles from one ecological group, while the solonetz displayed similarly non-impressive ecological others had marginal ecological structure. The ground group structure with about equal representation of psy- beetle taxocoene specific for the forest-steppe zone, chromesophiles (33%) and grass psychrobalancephiles was found to assemble in the waterlogged, but drying (28%). The darkling beetle taxocoene in its ecological by mid-summer wet meadows, where as many as 60– group structure showed the dominance of psychrobal- 80% of the animals represented grass psychrohygro- ancephiles (81%), with the rest contributed by psy- philes, and only 12–15% and 13% belonged to forest chromesophiles both in ground and darkling beetle psychrohygrophiles and grass cryohygrophiles, respec- assemblages. All these varying assemblages should be tively. considered as proto-communities with marginal, or tran- Nonetheless, original ground beetle taxocoene was sitional between indigenous communities, features and found in the mesophytic and watershed moderately wet very unstable in time ecological structure. This phenom- meadow of the TR positions on catena: the taxocoene enon is very characteristic for the forest-steppe biome. was dominated by grass psychromesophiles (57–67%) Notably, the chernozemic steppe subzone of the with a certain contribution by forest psychromesophiles Central Kazakhstan in the EL-positions displayed the (10–32%). The darkling beetles of the assemblage were ground beetle ecogroups assemblages that were very dominated by the grass psychromesophiles (94–100%). similar to the ones in the meadow steppes and stepped The contribution of psychrobalancephiles in the mead- meadows of the forest-steppe zone. Both study sites ow assemblages was practically negligible both for the were dominated by grass psychrobalancephiles (62 and ground (4%) and darkling (6%) beetles. Thermoxero- 54%, resp.), while thermoxerophiles contributed just philes were not observed in such communities even in 24% into the ground beetle assemblages only in the the very dry years. south of the subzone, where chernozems are represent- The meadow steppes and dry meadows at the sum- ed by their southern subtype, very similar to the dark mits of steppe ridges, i.e. the habitats experiencing kastanozems. The ground beetle taxocoenes of the cher- periodic moderate water deficit, theoretically can be nozemic steppes were shown to have only 6% of the expected to be inhabited by some xerophilous organ- thermoxerophiles, 10% of the thermomesophiles, and isms. However, the latter were found among neither similarly to the meadow steppes of the forest-steppe the ground, nor the darkling beetles; instead, grass zone being dominated by psychrobalancephiles (81%). psychrobalancephiles (62–76%) in combination with The TR positions of chernozemic steppes catenas had grass psychromesophiles (14–17%) dominated in such the ground beetle taxocoenes dominated by thermome- assemblages. Grass thermomesophiles, rather than ther- sophiles (75%) and the darkling beetle taxocoenes dom- moxerophiles, comprised up to 20% of the ground inated by psychromesophiles (57%). The thermoxero- beetle faunal assemblages. In contrast, the grass ther- philes accounted only for 2% in the ground beetle momesophilic darkling beetles were not observed in assemblages and 17% in the darkling beetle ones. Hence the meadow steppes. All three meadow faunal assem- both taxocoenes seemed to be more of a meadow, blages were characterized by the highest abundance in rather than steppe, character. the forest-steppe. Thus it makes sense to regard them as Undoubtedly steppe character could be attributed a single meadow type, indigenous in the forest-steppe, to the ground and darkling beetle assemblages on the the latter essentially being the park-meadow zone. EL positions in the dry steppe on kastanozems as they Alongside with indigenous insect faunal assemblag- showed a very pronounced dominance of thermoxero- es, dominated either by psychrohygrophiles, or psy- philes (94% among the ground beetles and 85% among chromesophiles, or grass psychrobalancephiles, some the darkling ones). The TR positions in the dry steppe forest-steppe habitats were shown to have assemblages zone were dominated by thermomesophiles (84% among with an obscure dominant structure of ecological groups, the ground beetles and 67% among the darkling ones). 176 V.G. Mordkovich

Figure 2. The diagram of ecological linkage and successional transformations of grass ground beetle communities in the West Siberian and Central Kazakhstan forest-steppe. M — 0.1 =5 mm. p Ðèñóíîê 2. Ñõåìà ýêîëîãè÷åñêèõ ñâÿçåé è ñóêöåññèîííûõ òðàíñôîðìàöèé òðàâÿíûõ ñîîáùåñòâ æóêîâ-æóæåëèö â Çàïàäíî- Ñèáèðñêîé ëåñîñòåïè Öåíòðàëüíîì Êàçàõñòàíå. Ì — 0,1 =5 ìì. ð

The deserted steppe assemblages were dominated (No.5), watershed (No.4) and mesophytic (No.3) mead- by the ardoxerophiles thermoxerophiles (94–96%). ows is considered to reflect ecogenetic succession of The comparison of the ecological structure of the the gradual changing of forest derivatives into a typi- studied taxocoenes by using the dissimilarity index (p) cally meadow coenosis. This process is marked by the allowed distinguishing several subsets of communities substitution of forest psychromesophiles with grass psy- in the ground and darkling beetle assemblages. The chromesophiles in the ecological assemblages. In the dissimilarity index within the subsets is rather low (0.2– course of succession the share of forest psychromeso- 0.4), while between the subsets exceeds 0.5 and can philes in species composition decreases from 70 to even reach its maximum of 1 (Fig. 2). 10%, while the share of grass psychromesophiles in- The first subset combining the taxocoenes of the creases from 15 up to 67%. ground and darkling beetles of the park forest (one of The second subset joins together the taxocoenes of the indigenous biogeocoenotic archetypes of the for- the ground and darkling beetles of the semihydromor- est-steppe biome), as well as of the near-to-forest- phic habitats, thus reflecting succession changes of the Beetles in the west-siberian steppes 177 gradual degradation of grass mires (that represent an- and dry meadows were inherited by the forest-steppe other biogeocoenotic archetype of the forest-steppe from the preceding it in the Quaternary history Perigla- biome) into the wet (No.1), moist (No.2) and then cial period with of extreme heterogeneity of habitats mesophytic (No.3) meadows, according to the histori- and biodiversity. cal process of the West-Siberian forest-steppe drying 3. Despite the difference between archetypes, their during the second half of Holocene. The beetle fauna phylocoenogenesis went in one and the same direction, responded by the gradual dropping out of grass cryo-, i.e. towards meadow coenoses dominated by plants- and then psychrohygrophiles from 64% to 2%, and mesophytes and grass psychromesophylous insects. their total substitution by grass psychromesophiles. Meadows seem to be the ecosystems of the biogeo- The third subset is comprised of the taxocoenes of coenotic climax in the forest-steppe, although in cate- the ground and darkling beetles of the meadow (No.8) nas they occupy not only eluvial, but transitional posi- and dry (No.10) steppes on chernozems, as well as of tions, where environmental conditions represent very the dry meadow on the middle solonetz (No.7) and well the hydrothermal standards for the forest-steppe once again of the mesophytic meadow on the meadow- zone, and where the biological turnover is balanced chernozemic soil (No.3). This subset illustrates well best [The structure, functioning and evolution , 1976]. the ecogenetic succession of the gradual changing of 4. If meadows and their corresponding zoocoenoses the dry meadows (yet another biogeocoenotic arche- represent climax ecosystems universal for all scenari- type of the forest-steppe biome) into true meadows, os of successional sequences and phylocoenogenesis, according to the historical trend of extra water dis- and if they can be found in a wide range of habitats and charge through the superficial water flow into the Aral, account for not less than 70% of the zone area [Vagina, the drainage of the territory and partial erosion of hills 1962], then what are the reasons to consider fragmen- in mid-Holocene [The structure , 1974]. As a result, tary insular forests and meadow steppes, unimpressive the balance between organic matter mineralization-hu- in composition and structure , and which V.V. Alekhin mification shifted towards humus accumulation, which [1934] called a “vegetation anomaly”, to be zonal ref- led the metamorphosis of soil and biogeocoenoses to- erence ecosystems? wards meadow development. Under such successional 5. We suggest to denounce the landscape-zonal scenario psychrobalancephiles are substituted by the stereotype, of which many are already tired, and con- grass psychromesophiles. The proportion of psy- sider the forest-steppe zone and its corresponding biome chrobalancephiles in the assemblages gradually dimin- to be indigenous phenomenon, rather than the marginal ished from 67 to 33 and further to 17%, while the grass mix. A meadow coenosis in such a case gets a status of psychromesophiles proportion increases from 4 to 28 the zonal reference ecosystem of the considered zone, and eventually up to 54–57%. The representatives of rather than being a secondary state intrazonal intrusion. the thermoxerophilous ecogroup do not participate in It is turn the considered zone should be referred to as a the process, instead of themselves allowing thermome- meadow zone, rather than the one of steppes and forests. sophiles to contribute up to 25%. However, psychrobal- 6. The analysis of the ecological group dominance ancephiles and psychromesophiles continue to be im- in beetle faunas provided reasons to consider meadow portant ecogroups of the beetle fauna. and dry steppe communities on chernozems as belong- The fourth subset combines the taxocoenes of the ing to the meadow zone, rather than the steppe one, as ground and darkling beetles of the meadow solonetz of their leading positions are occupied by psychrobalan- the forest-steppe and steppe zones (Nos.14, 11, 6) and cephiles and mesophiles and not xerophiles. Accord- once again of the mesophytic meadows (No.3). This ingly, the chernozemic steppe subzone much more nat- subset reflects the ecogenetic succession of the gradual urally can be joined with the meadow zone, rather than changing of the archetypical halocoenoses into glyco- the steppe one. The former is dominated by chernozems coenoses. In this subset the thermomesohalophiles are and humification processes, while the latter is dominat- gradually substituted by grass psychromesophiles. The ed by kastanozems and organic matter mineralization share of the former decreases from 84 to 13%, the processes. In the meadow zone zoocoenoses are based share of the latter increasing commensurately. on psychrobalancephiles and mesophiles, while in the steppe zone thermoxerophiles are the major compo- Discussion nent of its zoocoenoses. 7. We believe that the concept of broad expansion The study presented above allows drawing several of forest and steppe species into the forest-steppe and conclusions worth discussing. their balanced co-existence there, at least in case of 1. Successions in the forest-steppe zone have many ground beetles, darkling beetles and some other groups scenarios according to different ecological trends, com- of animals, is a myth. Entomological assemblages of mon for the forest-steppe landscape. the forest-steppe tree and grass stands are quite indige- 2. All four scenarios described here originate in nous and dissimilar to the ones of both Siberian taiga their own coenotic archetypes, resembling each other and steppe, at the same displaying certain similarity neither in form, nor in biotic composition and struc- (30–40%) with the forest-steppe faunal assemblages of ture. All those grass mires, park forests, halocoenoses the southern Urals and the Russian Plain [Mordkovich 178 V.G. Mordkovich et al., 2010]. Occurrence of some individuals of south- References ern insects in the north of the steppe zone should be regarded as a manifestation of a trait common to all Alekhin V.V. 1934. [Central chernozemic steppes]. Voronezh. 273 biota, i.e. expansion [Mordkovich, 2005], or stochastic pp. [in Russian] Arnoldi K.V. 1965. [The forest-steppe of the Russian Plain and the attempts to expand one’s geographical area, rather attempts of its zoogeographic and coenotic characteristics based than a vector response to the global warming and for- o insects] // Trudy Tsentral’no-Chernozyomnogo gos. zapoved- mation of sustainable arid communities. nika. Voronezh. Vol.8. P.138–166 [in Russian]. Berseneva I.A. 2006. [Climates of the arid zone of Asia]. Moscow: 8. In contrast to the stenopotent cryo- and thermo- Nauka Publ. 271 pp. [in Russian]. philes, forest-steppe psychrophiles with their euripo- Ghilarov M.S. 1965. [Zoological method of soil diagnostics]. Mos- tency under certain conditions are capable of broad cow: Nauka Publ. 273 pp. [in Russian]. geographic expansion and even colonization of new Khansky I. 2010. [A shrinkling world. Ecological consequences of habitat extinction]. Translated from English. Moscow: KMK habitats in the forest and steppe zones, which are at the Publ. 340 pp. [in Russian]. initial and middle stages of succession after fires, flood- Magurran E. 1992. [Ecological diversity and its measurement]. ings, landslides, permafrost ground shifts, forest clear- Translated from English. Moscow: Mir Publ. 1992. 181 pp. [in Russian]. ance, ploughing and other stresses. The share of psy- Mordkovich V.G. 2005. [The basics of biogeography]. Moscow: chrophiles in such communities may reach 70–80%. KMK-Press. 236 pp. [in Russian, with English summary]. 9. In view of all the data presented, the latitudal Mordkovich V.G. 2010. 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In case of the future climate Mordkovich V.G., Barkalov A.V., Vasilenko S.V., Grishina L.G., changes ecological collisions in the forest-steppe may Dubatolov V.V., Dudko R.Yu., Zinchenko V.K., Zolotarenko turn out to be the major driving force of biodiversity G.S., Legalov A.A., Marchenko I.I., Chernyshev C.E. 2002. [Species richness of the arthropods of the West Siberia Plain] // transformation in the West Siberian region. Evraziatskiy Entomologicheskiy Zhurn. Vol.1. No.1. P.3–20 [in Russian, with English summary]. Mordkovich V.G., Lyubechanskii I.I. 2010. [Ecological groups of Acknowledgements the ground beetles (Coleoptera, Carabidae): the nature, princi- The study was financially supported by the Russian ples of grouping, compositions and usability] // Evraziatkiy Foundation for Basic Research (grants ## 95-04- Entomologicheskiy Zhurn. Vol.9. No.2. P.195–202 [in Rus- sian, with English summary]. 12461a, 01-04-49533a. The author thanks Dr. I.I. Ly- [The structure, functioning and evolution of the Baraba biogeo- ubechanski for the possibility to use his published data coenoses]. 1974. Novosibirsk: Nauka Publ. Vol.1. 307 pp. [in on ground beetles. The author is thankful to Dr. R.Yu. Russian]. Dudko for checking the taxonomical attribution of the [The structure, functioning and evolution of the Baraba biogeo- coenoses]. 1976. Novosibirsk: Nauka Publ. Vol.2. 495 pp. [in ground beetles and to Dr. N.B. Naumova for translat- Russian]. ing the paper. Vagina T.A. 1962. [The Baraba meadows]. Novosibirsk: Nauka Publ. 127 pp. [in Russian].