2 PALEOENVIRONMENT. THE STONE AGE

E.V. Bezrukova1, D.G. Anderson2, O.P. Vinkovskaya3, A.V. Kharinsky4, and N.V. Kulagina5 1Irkutsk Laboratory of Archaeology and Paleoecology, Institute of Archaeology and Ethnography, Siberian Branch, Russian Academy of Sciences, Favorskogo 1A, Irkutsk, 664003, E-mail: [email protected] 2Department of Anthropology, University of Aberdeen, Aberdeen AB24 4QY, United Kingdom E-mail: [email protected] 3Irkutsk State Agricultural Academy, Molodezhnii1/1, Irkutsk, 664036, Russia E-mail: urbanofl [email protected] 4Irkutsk State Technical University, Lermontova 83, Irkutsk, 664074, Russia E-mail: [email protected] 5Institute of the Earth’s Crust, Siberian Branch, Russian Academy of Sciences, Lermontova 128, Irkutsk, 664033, Russia E-mail: [email protected]

VEGETATION AND CLIMATE CHANGES IN THE BOLSHOE INYAPTUKSKOE LAKE BASIN (NORTH BAIKAL PLATEAU) IN THE MIDDLE AND LATE HOLOCENE

This article presents new interdisciplinary observations relating to environmental changes in the Bolshoe Inyaptukskoe Lake Basin, North Baikal Plateau. A column taken from a loam/turf deposit at 1320 m above sea level is shown to refl ect changes in vegetation and climate over the last 8–9 thousand years through its palynology, radiocarbon chronology, and the count of charcoal particles. The chronology of the reconstructed changes in the vegetation around the Ozernyi-5 trench agrees well with existing regional and global climatic trends. However, the local processes also show their own peculiarities. The discrepancies are associated with the elevation and the altitude of the site. Keywords: , North Baikal Plateau, high resolution pollen record, vegetation and climate changes, Middle Holocene, Late Holocene.

Introduction the Holocene and responded to them rather rapidly (Bezrukova, 1999; Demske et al., 2005; Tarasov et al., It is well known that the vegetation of the Baikal region, 2007; Tarasov, Bezrukova, Krivonogov, 2009). It has which includes the North Baikal Plateau, was highly been also demonstrated that climatic changes in this susceptible to global and regional climate changes during territory occurred almost synchronously with the climate 3 oscillations of the Northern Hemisphere (Prokopenko average annual precipitation exceeds 500 mm while in the et al., 2010). Until recently, no continuous, dated, high intermontane basins, it is 300–350 mm. The thickness of resolution pollen records of environmental changes have snow cover fl uctuates markedly: from 20–30 cm to 180– been obtained for the mountainous part of the North 200 cm in areas near . The main air currents are Baikal Plateau. This region presents itself as a large inland western. In summer and autumn, the effect of northwestern system of medium-sized mountains and fl at-topped ridges winds increases. The North Baikal Plateau is situated in the with contrasting relief, fl ora, and climate, and a complex zone of discontinuous permafrost (Baikal…, 1993). glacial history. The diversity of plant communities on the North This article presents the fi rst results of palynological Baikal Plateau is determined by zones which vary by study of loose mineral and organic (peat) sediments from altitude. Mountain taiga (larch and pine-larch forests), the basin of Lake Bolshoe (Great) Inyaptukskoe located subalpine (larch forests with dark conifers and Siberian on the North Baikal Plateau. The results are unique for dwarf pine), and mountain tundra zones are characteristic the region due to the fi ne-grained selection of samples of this region (Zony…, 1999). which makes it possible to read pollen changes with a The Ozernyi-5 trench was placed within the subalpine 180 year resolution on average. Such detailed information larch forest belt in the Olokit River valley, near Bolshoe makes it possible to trace environmental variations Inyaptukskoe Lake (Fig. 1). The valley fl oor consists beyond the regional level, to trace local vegetation of a wetland covered with dwarf birch and tussock changes (Kuoppamaa, Goslar, Hicks, 2009; Schlütz, meadows. The slopes of the southern and western valleys Lehmkuhl, 2007), and to establish the causes of these are covered by subalpine larch open woodlands with changes as either climatic or anthropogenic. The impact dark conifers and Siberian dwarf pine (Fig. 2). Alpine of anthropogenic factors is not analyzed in full here. tundra plant communities (primarily, dwarf birch with Instead we focus on the way that major climatic changes were manifested in a peculiar way in mountainous areas. 0 40 km

Description of the study area

The Ozernyi-5 trench (56°22′49.1″ N; 109°54′09.0″ E) was located at the northeastern foothills of the Synnyr Ridge in the central portion of the North Baikal Plateau – a part of the Baikal Mountains lying between the Stanovoi Highland and the and Vitim river valleys. The highest peak of the North Baikal Plateau is Mount Inyaptuk; it reaches 2578 m asl. Bolshoe Inyaptukskoe Lake lies 10 km west of the peak. In the 19th–20th centuries, a camp of Evenki reindeer-herders was situated on its western shore; and in the mid-20th century, a settlement of geologists was built there (Kharinsky, 2010). The Ozernyi-5 trench was dug on the northeastern periphery of the former reindeer-herding camp, 370 m from the lake shore. This region has a continental climate. The annual temperature varies from –5 to –12 °С and the winters are cold and long. Temperatures in January average –30 °С. The daily temperature drops below zero until May. Summers are short and moderately warm. At the elevation of 500– 600 m, the mean July temperature does not exceed +14 °С, while the growing season lasts for less than 90 days (Atlas…, 1967). Most precipitation falls in July and August as well as in the first half of the autumn. In mountainous areas, the Fig. 1. The location of the Ozernyi-5 trench. 4

Pollen analysis. One sample was taken from every centimeter of the column creating an archive of 50 samples. To extract pollen and spores in the laboratory, 1 cm3 of undried sediment from each layer Ozernyi-5 was processed using a standard process using hydrofluoric acid followed by acetolysis (Faegri, Iversen, 1989). Before the start of the procedure, two tablets of Lycopodium clavatum marker spores (18,584 grains per tablet) were added to each sample in order to control the pollen concentration (Maher, 1981). Pollen grains and spores were counted until either their total number, or the quantity of the Lycopodium markers reached 1000. The count of naturally-occurring Lycopodium spores was excluded from these totals. The relative percentage of all pollen-bearing Fig. 2. Bolshoe Inyaptukskoe Lake from the southwest. taxa was calculated relative to the total count of pollen coming from terrestrial species. The percentages of spores from lichen) are more pronounced on the northern and eastern fern, moss, and club moss were calculated relative to slopes. Vegetation near the Ozernyi-5 trench is part of the total count of both pollen grains and spores in each the valley wetland system with hummocks covered by sample. At the same time, the number of charcoal particles ground birch (Betula rotundifolia Spach), isolated larches was counted from the same prepared samples. The counts (Larix dahurica Laws.), juniper (Juníperus communis L.), of each charcoal microparticle were calibrated to the size golden rhododendron (Rhododendron aureum Georgi), of 30 microns in diameter (the approximate size of a grain bilberry (Vaccínium uliginosum L.), white arctic mountain of the Lycopodium clavatum marker) (Innes, Blackford, heather (Cassiope tetragona (L.) D. Don), crowberry Simmons, 2004). We did not carry out an inventory of (Empetrum sibíricum V.N. Vassil.), and lingonberry different sizes of charcoal. (Vaccínium vítis-idaea L.). Lichen grows above the soil AMS dating. Two bulk AMS dates were obtained surface of hummocks. Hollows between the hummocks from samples taken from the depths of 19 and 32 cm at the are occupied by willows (Salix arctica Pall., S. bebbiana Ångström laboratory at Uppsala University in Sweden. Sarg., S. coasia Vill., S. divaricata Pall., and others) The fi rst was taken from the bottom of the layer composed and by tussocked cotton grass or grassy sedge bogs on of light gray loam. The second, from an isolated black permafrost-affected meadow soil. loam layer. The uncalibrated radiocarbon dates for these samples are 5935 ± 36 (Ua-38926) and 7005 ± 40 (Ua-38927), respectively. The dates when calibrated Materials and methods using CalPal software give the values of 6764 ± 50 (68 % confi dence limit: 6713–6814 calibrated years) and The trench was dug near Ozernyi, an abandoned 7858 ± 56 (68 % confi dence limit: 7801–7914 calibrated settlement built by geologists, at an elevation of 1320 m years) (Danzeglocke, Joris, Weninger, 2011). Only the asl in the Olokit River valley. The trench was 50 cm deep calibrated dates are cited from this point forward. and was composed primarily of loam sediments with turf The alternation of light and dark conifer taxa. in its upper part. A damp site was chosen near to an alpine Light conifers are represented by Pinus sylvestris and lake with the expectation that it would better preserve a Larix. The group of dark conifers includes Pinus sibirica, local pollen signature. Further, the trench was placed near Abies sibirica, and Picea obovata. Given the different a camp once used by reindeer-herders with the hope that ecological (edaphic and climatic) needs of these two we would pick up a signature of pollen associated with groups of arboreal species, changes in the counts of their the concentration of a large number of domestic animals pollen are thought to point to changes in the continental once held there. This methodology of site selection was climate (Bykov, 1960; Koropachinsky, Vstovskaya, developed in Scandinavia, where pollen samples are taken 2002). This is usually interpreted as a change in the 6–50 m away from a geoarchaeological object (Aronsson, relative humidity or as a change in the difference between 1991; Räsänen, Froyd, Goslar, 2007). the mean temperatures in summer and winter. 5

Results as signifi cant and therefore allowing us to reconstruct the plant communities. Arboreal pollen dominates (56–72 %) Chronology. In order to reconstruct the rate of change with Siberian pine and Scotch pine (Pinus sylvestris) being in the occurrence of plant taxa in the Ozernyi-5 trench, most common. However, spruce and Siberian fi r (Abies and to assess the chronology of pollen zones, a linear sibirica) are also well represented. Amongst the shrubs, interpolation was made between the two calibrated the pollen of dwarf birch dominates with a small quantity dates. The age of the top sample was set at zero. The of shrub alder (Duschekia fruticosa). The quantity of dates below the lowest dated sample were extrapolated. Botrychium, Polypodiophyta, and Lycopodium clavatum To generate a more reliable chronology of changes in pollen reaches its highest level in the history of the the either the regional or local pollen signatures, events formation of the Ozernyi-5 trench. The concentration of were correlated to other paleogeographic events which pollen and spores in the sediments of this subzone varies were known to cause drastic climatic changes in the greatly, but generally remains within 400 to 56,000 grains Northern Hemisphere. The date of their appearance and per 1 cm3. The number of charcoal particles increases near their duration serve as additional time markers. Our time the upper boundary of the subzone. model suggests that the bottom level of the trench may OZY-2 (20–14 cm, ~ 6.8–4.3 ka BP). Here, there is have formed before 9 ka BP (Fig. 3). a relative abundance of pollen from fi r, larch (Larix sp.), The assessment of accumulation rates between the Siberian fi r, and dwarf birch. The pollen from wormwood dated horizons indicates a marked decrease in the upper (Artemisia) reaches its maximum. The concentration layer (0–19 cm) when compared to the lower layer (19– of pollen and spores increases sharply, reaching 32– 32 cm). This may be due to landscape or to environmental 62 thousand grains per 1 cm3. The sediments of this factors which favored the quite rapid formation of a black subzone contain the maximum number of charcoal and then gray-yellow loam before 6.7 ka BP, and then fragments. the accumulation of a light-yellow loam with a very low OZY-1 (12–0 cm, ~ 4.3–0 ka BP). The unique quality content of organic matter from ca 6.7 to 4 ka BP. The of the spectra of this subzone is a sharp decrease in the upper 12 cm layer of turf may also have accumulated amount of spruce and dwarf birch pollen and an increasing gradually, because it was formed during the Neoglacial number of pollen from Siberian pine, Scots pines, and cooling after 4 ka BP. willow (Salix). The spores of spike moss (Selaginella Palynostratigraphy. The pollen diagram has been selaginoides) are always present. The pollen of sedge divided into three local pollen zones (OZY) on the basis (Cyperaceae) dominates the group of herbaceous plants. based of changes in the counts of various individual taxa The concentration of pollen and spores reaches its and the sum total of the pollen of light and dark coniferous maximal here. The counts of the number of charcoal species. These changes were identifi ed visually. The zones particles gradually decrease. are numbered starting from the top. The lower zone is The proportion of dark and light coniferous subdivided in two subzones (Fig. 3). taxa. The gray area at the bottom of Figure 4 marks the OZY-3б (50–32 cm, > 9–7.8 ka BP). Most of the insignifi cant spectra counts. The reconstructions here spore-pollen spectra (SPS), 18 of 29 samples, within should be regarded as tentative. The diagram is divided this subzone contain less than 100 pollen grains. In into three zones which represent noticeable differences nine spectra, the total sum of pollen and spores does in the proportion of dark and light coniferous taxa. SPS not exceed 100. Although the relative quantity of formed greater than 9–7.7 ka BP are dominated by pollen individual taxa for these SPS have been calculated and of dark conifers (spruce and Siberian pine), although the indicated by dots in the graph, they cannot be used meaning of the total counts of pollen from each group is reliably to reconstruct the vegetation history. Generally highly ambiguous. The relative quantity of pollen from speaking, SPS from the 50–30 cm interval of the trench dark conifers remains high (65–85 %) in the period from (> 9–7.7 ka BP) are dominated by Sphagnum and around 7.7–4.3 ka BP. In the sediments accumulated Lycopodium spores including the modern tundra species over the past 4.3 thousand years, the dark conifer counts Lycopodium pungens. In the arboreal group, spruce gradually decrease from 60 % to 50 %. This is especially (Picea obovata) and Siberian pine (Pinus sibirica) are visible in the most recent centuries. especially common. Grains of dwarf birch (Betula nana- type) are dominant amongst the shrubs. Herbaceous plants are mostly represented by the pollen of Asteraceae, Interpretation and discussion Brassicaceae, and Geraniaceae. Charcoal is scarce in this subzone. The results from the Ozernyi-5 sequence suggest that OZY-3а (32–20 cm, ~ 7.8–6.8 ka BP). In the SPS of the changes in the plant communities can be grouped this subzone, the number of calculated pollen grains varies into three major periods over the past 9 thousand years from 150 to 1000 making it possible to consider all spectra which in turn suggest changes in the regional climate 6 – location of dated samples. 5 – black loam; 4 – grayish-yellow loam; 3 ed spore and pollen diagram of the Ozernyi-5 trench. fi A simpli A – light gray loam; 2 Fig. 3. – upper soil layer, turf; – upper soil layer, 1 12 345 7

Fig. 4. The relative changes in dark and light coniferous forests near Ozernyi-5 in comparison to the variation of δ18O NGRIP. The latter indicates atmospheric temperature fl uctuations in the North Atlantic region (Svensson et al., 2008). The chart also indicates the cold periods known as Bond events (Bond et al., 2001) and the fl uctuations of δ18O in stalagmites from Dongge Cave in China (Yuan et al., 2004) which serves as an indicator of the intensity of the Pacifi c monsoon.

and natural environment. The lower part of the 9– spruce forest once stood near the trench. The pine pollen 7.7 ka BP sequence consists of a grayish-yellow loam should be regarded as an element carried from afar. which accumulated slightly earlier than 8 ka BP. The According to previous reconstructions of landscape and composition of the spectra here seems to correspond climate, subglacial warming in the Baikal basin occurred with the expansion of shrub herbaceous tundra 11–10 ka BP (Tarasov et al., 2007; Tarasov, Bezrukova, communities with Siberian dwarf pine and dwarf birch. Krivonogov, 2009; Bezrukova et al., 2010), although The study of modern plant communities of this type the most humid and warm conditions are thought to suggest that they lived in an ecological and geographic have occurred between 10–7 ka BP. During that time setting which was a cold and rather humid climate with period, forest plants became dominant and the share an accumulation of permafrost. The climate then was of fi r and spruce reached its maximum for the whole likely characterized by cold winters with little snow, Holocene. Pine was an insignifi cant component of the which made possible the freezing of the soil to a great forest vegetation in the Baikal area and contiguous depth. The summers were likely relatively warm but regions (Bezrukova et al., 2005; Prokopenko et al., 2010; short. They nevertheless afforded plants with enough Bazarova et al., 2011). available water in the soil during the time that the active The later accumulation of a thin layer of black loam layer of the permafrost thawed. The high hypsometric (31–32 cm from the top of the trench) was dated to position of the site and constant strong winds could 7.8 ka BP. The deposition of the upper portion of the have also contributed to the weak growth of arboreal grayish-yellow loam layer continued up to ca 6.5 ka plants. The SPS display in separate layers a considerable BP. However, based on signifi cant changes in the SPS, number of pollen grains from spruce and both Siberian we drew the upper boundary of zone OZY-3 lower at and common pine. These taxa have marked differences ~ 7–6.8 ka BP. The most noticeable change here was the in their ability to travel (Peterson, 1983; Bezrukova et constant increase in the amount of Pinus sylvestris pollen al., 2005). Their presence may indicate that an open that corresponds to similar increases recorded in pollen 8 records from other regions of Siberia (MacDonald et al., the local site. Similar changes in arboreal taxa are also 2000; Bezrukova et al., 2005; Demske et al., 2005). It typical to other parts of the Baikal region (Bezrukova is important to note that another similar and statistically et al., 2006, 2008; Belov et al., 2006). A quantitative signifi cant regional Holocene event was recorded in reconstruction of climate indicators demonstrated the neighboring Baikal range in an environmentally that in the 4th and 3rd millennia BC the mean annual similar alpine setting (Bezrukova et al., 2008). Generally precipitation might have been 20–30 mm below, and speaking, the results of our study suggest that between mean summer and winter temperatures 1.5–2 °С greater 7.8–6.8 ka BP (OZY-3а) the Ozernyi-5 area was than those during the Holocene optimum. The moisture dominated by trees and shrubs. Among the trees, the dark index dropped signifi cantly during this time (Tarasov et conifers such as spruce and Siberian pine predominated. al., 2007). This reconstruction of the changes to the plant Given the poor transportability of fi r pollen (Bezrukova, communities around the Ozernyi-5 trench corresponds 1999), its predominance in this zone suggests that fi r to changes to the regional climate. Further, they point to was quite common in this locale at this time. This also continuous reduction of dark conifer community. Such correlates with the fact that its general distribution was environmental and climatic conditions could have led greatest within the Baikal region during the period to a greater thawing of the permafrost in turn leading 10–7 ka BP. The greater number of charcoal fragments to a greater amount of available water in the locale. could possibly be explained by an increase in the volume This would have encouraged the expansion of the sedge of combustible material due to either the widening communities and appearance of spike moss (Selaginella of distribution of trees and shrubs or their increased selaginoides selaginella) on stream banks, among the density. Key records of climate changes across the dwarf birch, and on wet rocks. Larch remained the Northern Hemisphere suggest the gradual decline in the most important element of the local forest community. atmospheric temperature in the North Atlantic region High soil humidity may have reduced the frequency of (Svensson et al., 2008) and a weaker and cooler Pacifi c forest fi res, as indicated by a lower content of charcoal monsoon (Yuan et al., 2004). Variations in the counts of particles in the OZY-1 sequence. pollen grains from dark and light conifers speak to the The expansion of sedge remains and the permanent dominance of dark coniferous plant communities around presence of willows in the region during the last the Ozernyi-5 trench during this period. millennia may have two explanations. One may be an The persistent presence of pollen representing anthropogenic effect. This suggestion can be supported arctic and alpine bushes (primarily, dwarf birch and, by the following arguments. In the modern observable less commonly, shrub alder and Siberian dwarf pine) vegetation community, sedges (especially Carex suggests that over the period ~ 6.8–4.3 ka BP (OZY-2), caespitosa) are dominant in the eutrophic swamps. Their this locale was occupied by plant communities typical high frequency in the spectra could be the result of the of shrub tundra. The high counts of spruce pollen overpasturing of ungulates and the consequent trampling might indicate that this tree was most common around of damp soils with their hooves. The contemporary Ozernyi-5 during this time period. Even the low counts territory around Bolshoe Inyaptukskoe reveals one of larch pollen (0.1–0.2 %) testifi es that larch grew in other important feature: willow shrubs grow mainly in the environs of the trench, if we take into account studies depressions and on hilltops which had been trampled of how the pollen of this tree settles in SPS from other by people (normally these places are covered by sites in this region (Peterson, 1983; Bezrukova, 1999). fruticous birch shrubs). Therefore it is possible that These reconstructed dark and light coniferous complexes human activities in the past resulted in the replacement suggest that at this time the dark conifers enjoyed their of fruticous birch on hilltops by much faster growing widest distribution over the past 9 thousand years and, varieties of willows. However, the same palynological correspondingly, the presence at that time of a less- indicators can be interpreted as natural succession. Our continental and moderately-cold climate. The maximum comparison of the data with documented changes in amount of charcoal fragments can be used as an indirect vegetation that occurred in other parts of the Baikal indicator of a dense tree and shrub layer. region suggests a natural rather than anthropogenic The gradual decrease in arboreal pollen and the explanation for the changes in the plant communities increase in herbaceous pollen in the SPS of OZY-1 from near Ozernyi-5. A signifi cant cooling of the landscape ~ 4.3 ka BP to the recent times might be indicative of a and climate around 3–2 ka BP have been recorded in retreat or thinning of the forest plant communities. It is almost all medium and high latitude settings in the quite possible that the slight reduction in the counts of Northern Hemisphere: in Canada (Tillman et al., 2010), coal fragments also refl ect this. The increase in Pinus Europe (Wanner et al., 2008; Sёppa et al., 2009), and sylvestris pollen and the marked decrease of spruce Central Mongolia (Wang et al., 2009). In the Baikal pollen might indicate the further spread of pine over the region, this climatic event is refl ected in pollen records region and a signifi cant decline in spruce population at from the lower reaches of the Verkhnaya Angara River 9

(Bezrukova et al., 2006), Tazheran steppe (Bezrukova and a count of charcoal particles, a qualitative and semi- et al., 2005), and from the Lena-Angara plateau quantitative reconstruction of the fluctuations of the (Bezrukova, Belov, Orlova, 2011). continentality index, has resulted in a reliable picture of environmental change over the last 9 thousand years. The boundaries marking major changes in the plant The reasons behind the environmental changes communities around Ozernyi-5 can be correlated with around Ozernyi-5 regional and global climatic trends. There is also a local signature to the environmental changes in the region which To gain a better understanding of factors causing local can be associated with its geographic and orographic and regional environmental changes, we correlated location. Specifi cally, the maximum expansion of dark the sequence of reconstructed events with other coniferous forests took place during the period ~ 8– key sequences reflecting climatic changes in the 4.3 ka BP, while in the Baikal basin this occurred earlier Northern Hemisphere. Figure 4 shows the dynamics ~ 10–7(6) ka BP. In the Baikal region, contemporary plant of the proportion of dark and light coniferous taxa communities began to form after 7(6) ka BP, while around (DC/LC, index of relative variability of the climatic Ozernyi-5 this process started somewhat later. The main continentality). It compares this data with variations of reason for this offset of the time horizons for the local mean air temperatures in the North Atlantic, with the appearance of global and regional paleogeographic events variability of intensity of the Pacifi c summer monsoons, could be the high elevation and high latitude of the site. and with periods of cooling known as Bond events. It is clearly seen in the fi gure that the interval ~ 9.2–7.7 ka BP is characterized by unstable temperature in the North Acknowledgments Atlantic region and by the active summer (warm) monsoon. Values of the continentality index (DC/LC) This study was supported by the Research Council of Norway in the region are also unsteady. A relatively stable warm (Project NFR 179316, “Homes, Hearths and Households in period in the North Atlantic and Pacifi c regions occurred the Circumpolar North”); the Social Sciences and Humanities ~ 7.7–4.3 ka BP. The continentality index also points Research Council of Canada (Baikal Archaeological Project, to a rather stable moderately cool and humid climate SSHRC MCRI 412-2005-1004); the European Research Council (Arctic Domus AdG 295458); and the Russian Foundation for existing in the Ozernyi-5 region at that time. In the Basic Research (Project 12-05-00476а). The authors express Northern Hemisphere, the climate deterioration ended their gratitude to O.I. Shestakova for preparing samples for around 4.5–4 ka BP (Fig. 4, Bond event 3). It is possible palynological analysis. that the appreciable decrease in the dark coniferous taxa in the region under study ca 4.5 ka BP occurred at the same time as the deterioration of the global climate. The increasing cooling trend observable in both References stratotypic sections after 4.3 ka BP correlates well with intensifi cation of continentality in the Ozernyi-5 region. Aronsson K.A. 1991 The relationship between the later (4.3 ka BP – present) Forest Reindeer Herding AD 1 – 1800: An Archaeological reduction of dark coniferous vegetation at Ozernyi-5 and Palaeoecological Study in Northern Sweden. Umea: and global climate variations (Fig. 4) is less distinct. Department of Archaeology, Univ. of Umea. (Archaeology and the Environment; vol. 10). The reasons behind the decline of the dark coniferous Atlas Zabaikalya (Buryatskaya ASSR forests in the region during the Late Holocene need to i Chitinskaya oblast). 1967 be examined in more detail. Moscow, Irkutsk: Gl. upr. geodezii i kartografi i pri Sovete ministrov SSSR. Conclusions Baikal: Atlas. 1993 G.I. Galazii (ed.). Moscow: Federalnoe agentstvo geodezii A detailed sampling of the trench at Ozernyi-5 has made i kartografi i Rossii. it possible for the fi rst time to produce a high-resolution Bazarova V.B., Grebennikova T.A., record of environmental changes for this territory which Mokhova L.M., Orlova L.A. 2011 Golotsenovoe osadkonakoplenie v stepnoi zone Zabaikalya corresponds with the standard time periods used when (na primere otlozhenii ozera Zun-Soktui). Geologiya i geofi zika, studying the environmental history of the Holocene vol. 52, No. 3: 333–342. around the world. Despite the low content of pollen and Belov A.V., Bezrukova E.V., Sokolova L.P., spores in the lower part of the trench, new palynological Abzaeva A.A., Letunova P.P., Fisher E.E. 2006 and radiocarbon data suggest significant changes in Rastitelnost Pribaikalya kak indikator globalnykh i regio- pollen spectra and consequently in the vegetation in the nalnykh izmenenii prirodnykh uslovii Severnoi Azii v pozdnem Bolshoe Inyaptukskoe Lake basin. Using pollen analysis kainozoe. Geografi yia i prirodnye resursy, No. 3: 5–18. 10

Bezrukova E.V. 1999 profi les from the North York Moors, UK. Palaeogeography, Paleogeografi ya Pribaikalya v pozdnelednikovye i golotsene. Palaeoclimatology, Palaeoecology, vol. 214: 295–307. Novosibirsk: Nauka. Kharinsky A.V. 2010 Bezrukova E.V., Abzaeva A.A., Letunova P.P., Zhilische severobaikalskikh evenkov-olenevodov: Etno- Kulagina N.V., Vershinin K.E., Belov A.V., arkheologicheskii analiz. In Integratsiya arkheologicheskikh i Orlova L.A., Danko L.V. 2005 etnografi cheskikh issledovanii: Sbornik nauchykh trudov, pt. 1. Post-glacial history of Siberian spruce (Picea obovata) Kazan: Inst. istorii im. Mardzhani AN RT, pp. 190–194. in the Lake Baikal area and the signifi cance of this species Koropachinsky I.Yu., Vstovskaya T.N. 2002 as a paleoenvironmental indicator. Quaternary International, Drevesnye rasteniya Aziatskoi Rossii. Novosibirsk: Izd. vol. 136: 47–57. SO RAN. Bezrukova E.V., Belov A.V., Abzaeva A.A., Kuoppamaa M., Goslar T., Hicks S. 2009 Letunova P.P., Orlova L.A., Sokolova L. 2006 Pollen accumulation rates as a tool for detecting land-use Pervye detalnye zapisi izmeneniya rastitelnosti i klimata changes in a sparsely settled boreal forest. Vegetation History Severnogo Pribaikalya v srednem-pozdnem golotsene. Doklady and Archaeobotany, vol. 18: 205–217. Akademii nauk, vol. 411, No. 2: 254–258. MacDonald G.M., Velichko A.A., Bezrukova E.V., Belov A.V., Letunova P.P., Kremenetski C.V., Borisova O.K., Goleva A.A., Abzaeva A.A., Kulagina N.V., Fisher E.E., Andreev A.A., Cwynar L.C., Riding R.T., Orlova L.A., Sheifer E.V., Voronin V.I. 2008 Forman S.L., Edwards T.W.D., Aravena R., Biostratigrafiya torfyanykh otlozhenii i klimat severo- Hammarlund D., Szeicz J.M., Gattaulin V.N. 2000 zapadnoi chasti gornogo obramleniya ozera Baikal v golotsene. Holocene treeline history and climate change across northern Geologiya i geofi zika, vol. 49, No. 6: 547–558. Eurasia. Quaternary Research, vol. 53: 302–311. Bezrukova E.V., Belov A.V., Orlova L.A. 2011 Maher L.J. 1981 Holocene vegetation and climate variability in North Pre- Statistics for microfossil concentration measurements Baikal region, East Siberia, Russia. Quaternary International, employing samples spiked with marker grains. Review of vol. 237: 74–82. Palaeobotany and Palynology, vol. 32: 153–191. Bezrukova E.V., Danko L.V., Snytko V.A., Peterson G.M. 1983 Letunova P.P., Orlova L.A., Kuzmin S.B., Recent pollen spectral and zonal vegetation in the western Vershinin K.E., Abzaeva A.A., Sizykh A.P., USSR. Quaternary Science Review, vol. 2: 281–321. Khlystov O.M. 2005 Prokopenko A., Bezrukova E., Khursevich G., Novye dannye ob izmenenii rastitelnosti zapadnogo Solotchina E., Kuzmin M., Tarasov P. 2010 poberezhya ozera Baikal v srednem-pozdnem golotsene. Climate in continental interior Asia during the longest Doklady Akademii nauk, vol. 401, No. 1: 100–104. interglacial of the past 500 000 years: The new MIS 11 records from Bezrukova E., Tarasov P., Solovieva N., Lake Baikal, SE Siberia. Climate of the Past, vol. 6: 31–48. Krivonogov S., Riedel F. 2010 Räsänen S., Froyd C., Goslar T. 2007 Last glacial–interglacial vegetation and environmental The impact of tourism and reindeer herding on forest dynamics in Southern Siberia: Chronology, forcing and feedbacks. vegetation at Saariselka, Finnish Lapland: A pollen analytical Palaeogeography, Palaeoclimatology, Palaeoecology, vol. 296: study of a high-resolution peat profi le. The Holocene, vol. 17: 185–198. 447–456. Bond G., Kromer B., Beer J., Muscheler R., Schlütz F., Lehmkuhl F. 2007 Evans M.N., Showers W., Hoffmann S., Climatic change in the Russian Altai, southern Siberia, Lotti-Bond R., Hajdas I., Bonani G. 2010 based on palynological and geomorphological results with Persistent solar infl uence on North Atlantic climate during implications on teleconnections and human history since the the Holocene. Science, vol. 294: 2130–2136. middle Holocene. Vegetation History and Archaeobotany, Bykov B.A. 1960 vol. 16: 101–118. Dominanty rastitelnogo pokrova Sovetskogo Soyuza, vol. 1. Sёppa H., Bjune A.E., Telford R.J., Alma-Ata: Izd. AN KazSSR. Birks H.J.B., Veski S. 2009 Danzeglocke U., Joris O., Weninger B. Last nine-thousand years of temperature variability in CalPal-2007online. URL: http://www.calpal-online.de / Northern Europe. Climate of the Past, vol. 5: 523–535. Accesses 2011-11-26. Svensson A., Andersen K.K., Bigler M., Demske D., Heumann G., Granoszewski W., Clausen H.B., Dahl-Jensen D., Davies S.M., Nita M., Mamakowa K., Tarasov P. E., Johnsen S.J., Muscheler R., Parrenin F., Oberhansli H. 2005 Rasmussen S.O., Rothlisberger R., Seierstad I., Late glacial and Holocene vegetation and regional climate Steffensen J.P., Vinther B.M. 2008 variability evidenced in high-resolution pollen records from A 60 000 year Greenland stratigraphic ice core chronology. Lake Baikal. Global Planet. Change, vol. 46: 55–279. Climate of the Past, vol. 4: 47–57. Faegri K., Iversen J. 1989 Tarasov P., Bezrukova E., Karabanov E., Textbook of Pollen Analysis. New York: John Wiley & Nakagawa T., Wagner M., Kulagina N., Sons. Letunova P., Abzaeva A., Granoszewski W., Innes J.B., Blackford J.J., Simmons I.G. 2004 Riedel F. 2007 Testing the integrity of fi ne spatial resolution palaeoecological Vegetation and climate dynamics during the Holocene and records: Micro-charcoal data from near-duplicate peat Eemian interglacials derived from Lake Baikal pollen records. 11

Palaeogeography, Palaeoclimatology, Palaeoecology, vol. 252: Wanner H., Beer J., Butikofer J., Crowley T.J., 440–457. Cubasch U., Fluckiger J., Goosse H., Grosjean M., Tarasov P., Bezrukova E., Krivonogov S. 2009 Joos F., Kaplan J.O., Kuttel M., Muller S.A., Late Glacial and Holocene changes in vegetation cover Prentice C., Solomina O., Stocker T.F., and climate in southern Siberia derived from a 15 kyr long Tarasov P., Wagner M., Widmann M. 2008 pollen record from Lake Kotoke. Climate of the Past, vol. 5: Mid to Late Holocene climate change: An overview. 285–295. Quaternary Science Review, vol. 27: 1791–1828. Tillman P.K., Holzkamper S., Kuhry P., Yuan D., Cheng H., Edwards R.L., Dykoski C.A., Sannel A.B.K., Loader N.J., Robertson I. 2010 Kelly M.J., Zhang M., Qing J., Lin Y., Long-term climate variability in continental subarctic Wang Y., Wu J., Dorale J.A., An Z., Canada: A 6200-year record derived from stable isotopes in Cai Y. 2004 peat. Palaeogeography, Palaeoclimatology, Palaeoecology, Timing, duration, and transitions of the last interglacial vol. 298: 235–246. Asian monsoon. Science, vol. 304: 575–578. Wang W., Ma Yu., Feng Z.D. Meng H.W., Zony i tipy poyasnosti rastitelnosti Rossii i Sang Y.L., Zhai X.W. 2009 sopredelnykh territorii: Karta. 1999 Vegetation and climate changes during the last 8660 cal. Moscow: Ekor. a BP in central Mongolia, based on a high-resolution pollen record from Lake Ugii Nuur. Chinese Science Bull., vol. 54: 1579–1589. Received July 28, 2011.