Late Holocene Vegetation Dynamics Research Articles

Late Holocene Vegetation Dynamics and Sea Level Fluctuations: A High-Resolution Record from Southeast India

A detailed high-resolution study of climate and vegetation changes in two sedimentary profiles from the Godavari delta in India was conducted to understand extreme climate variability over the last 3000 years. These historical climate records are vital for predicting future climate changes influenced by increased human activity. Pollen records reveal several climatic periods: (1) an initial warm/humid phase (2260–1560 cal yr BP) with mangrove and tropical tree pollen and maximum pollen accumulation rate (PARmax), (2) a gradual shift to drier conditions with reduced mangrove and arboreal pollen, coinciding with to the Dark Ages Cold Period (1580–1070 cal yr BP), (3) a Medieval Warm Period (1090–580 cal yr BP) marked by a stronger summer monsoon, rejuvenation of mangroves and tree pollen, (4) a relatively cool and dry phase with abundant dry deciduous and non-arboreal pollen possibly linked to the Little Ice Age (580–80 cal yr BP), showing a weakened monsoon, and (5) recent warming since 80 cal yr BP. A semi-quantitative aridity, temperature, and moisture index based on pollen concentration variations have also been used to identify centennial-scale climatic cycles in the pollen record.

Climate-driven peatlands development and vegetation dynamics in Northeastern China since the mid-Holocene: New evidence from Huanan peatlands

Studying peatland evolution and vegetation patterns in response to climate change provides valuable insights into future ecosystem trends. This study focuses on the Huanan peatland located in Changbai Mountain regions in Northeast China, utilizing phytolith analysis and stable carbon isotope composition (δ13C) to reconstruct late Holocene vegetation dynamics. Additionally, grain size, total organic carbon (TOC), and total nitrogen (TN) analyses were conducted to understand peatland development and paleoclimate since the late Holocene. The research identifies three distinct climate periods since 5500 cal yr BP: an initial warm, humid phase (5500–4000 cal yr BP) characterized by high river levels that formed lacustrine sediments; a subsequent transition to cold, dry conditions (4000–1500 cal yr BP) that initiated peat formation; and continued dry, cold conditions (1500 cal yr BP to the present) with sustained peat growth. Phytolith data reveal a dominant forest vegetation type since 2000 cal yr BP, further divided into three periods: 2000–1300 cal yr BP, marked by diverse and dense vegetation; 1300–750 cal yr BP, with declining plant cover; and 750 cal yr BP to the present, characterized by an increase in woody plants but a reduction in local grass cover.

Late Holocene vegetation dynamics: degree and regional patterns of the Dark Ages woodland regeneration (ad 300–700) in the Netherlands

AbstractDuring the Dark Ages, which include the Late Roman period (ad 270–450) and the Early Middle Ages (ad 450–1050), large-scale vegetation development in northwest Europe was characterised by widespread regeneration of woodlands. This regeneration phase represents a break from the extensive reduction in woodland from human activities in late Holocene vegetation history. In the Netherlands, possible causes for this reversal can be found in a decreased human impact on the landscape, a colder and possibly wetter climate, and geomorphological changes. This paper presents a synthesis from 38 pollen records from a range of sites across the Netherlands, from which regional differences in the degree of woodland regeneration and vegetation composition before and during the Dark Ages have been identified. Both original data as well as vegetation abundance modelled by REVEALS were used to assess the regrowth of the woodland cover. The observed trends were considered in terms of the landscape setting and population estimates in order to disentangle the relative importance of these forcing factors. The results indicate that landscape and human impact were the most important factors determining the vegetation structure and changes to it. The pollen data show that in the Netherlands, the clearance of woodland in the Roman period followed by its regrowth afterwards were greatest in the river area. This can be linked to a high population density there during the Roman period followed by a strong decrease of population in the Dark Ages and to increased flooding.

A multi-proxy reconstruction of the late Holocene vegetation dynamics in Krabi mangroves, Thailand Andaman Sea

Pollen, charcoal, loss on ignition, geochemistry, and geophysical analyses were used to reveal the palaeoenvironment, vegetation, and sedimentary dynamics of the Krabi mangroves and the Andaman coast during the late Holocene. Two sediment cores, radiocarbon dated to ∼4400 cal BP, were collected from the Nai Nang mangroves in Krabi Province, the Thailand Andaman coast. This analysis documented how the area evolved from a tidal channel to a tidal area dominated by mangrove ecosystems. During the tidal channel phase (∼4400–2700 cal yr BP), the study site was characterized by a high-energy depositional environment, where sediment accumulated along tidal channels. Mangrove development began around 4400 cal yr BP and was influenced by varying contributions from tidal and freshwater inputs. Sea level during this period showed a slight rise until ∼4200 cal yr BP, followed by a subsequent fall. From ∼2700 to 1050 cal yr BP, the tidal channel was filled with finer sediments, forming intertidal flats that supported mangroves, back mangroves, and freshwater forest taxa, indicating a transition to mixed coastal vegetation. Sea levels remained relatively low during this period. From around 1050 cal yr BP to the present, mangroves replaced the previous mixed coastal vegetation, most likely driven by rising sea levels, particularly during the last 200 years. The observed sedimentation rates indicate that mangroves in Krabi will need to undergo continued future landward migration to adapt to changing coastal conditions, given the current and projected global sea-level rise.

Late Holocene vegetation dynamics and monsoonal climatic changes in Jammu, India

Knowledge of the Holocene Indian Summer Monsoon (ISM) variability is important for understanding the spatio-temporal dynamics of the ISM precipitation. In this study, a Late Holocene pollen proxy record of the changes in the ISM intensity from a 1.8 m deep lacustrine sedimentary deposit in Jammu District (Jammu and Kashmir State) in India is presented. The results show that between ~3205 and 2485 cal yr BP, mixed broad-leaved/conifer forests occurred in the region under a warm and humid climate, probably indicating high monsoon precipitation. Subsequently, the conifers, such as Pinus sp., Cedrus sp., Abies sp., Picea sp. and Larix sp. increased comparatively and show dominance over the existing broad-leaved taxa between ~2485 and 1585 cal yr BP under a cool and dry climate with reduced monsoon precipitation. The climate further deteriorated (towards attaining aridity under reduced monsoon condition) during ~1585 to 865 cal yr BP, which coincides with the Dark Ages Cold Period (DACP: CE/AD 400–765; 1185–1550 cal yr BP). Since ~865 cal yr BP (CE/AD 1085 onwards) to Present, the broad-leaved taxa, such as Alnus sp., Betula sp., Ulmus sp., Carpinus sp., Corylus sp. and Quercus sp. started expanding and showed their dominance over the conifers, indicating a warm and humid climate in the region with increased monsoon precipitation. This phase partly corresponds with the Medieval Climatic Anomaly (MCA) between CE/AD 950 and 1300. Thus, the ISM rainfall intensity is linked with some of the global climatic trends in the present study.

Late Holocene peatland palm swamp (aguajal) development, carbon deposition and environment changes in the Madre de Dios region, southeastern Peru

Tropical peatlands are an important carbon reservoir; however, they are vulnerable to climate change, fire events, and human disturbances, and may become a significant carbon source if degraded. In this paper, we investigated the late Holocene record of vegetation change, peatland evolution, and C accumulation based on analysis of a sediment core through a Mauritia-flexuosa palm dominated swamp (locally called “ aguajal ”) in the Madre de Dios region in southern Peru to better understand tropical peatland dynamics. Sedimentation commenced within shallow water, ponded on an impervious substrate, perhaps within an abandoned river channel or oxbow lake (1380–820 cal yr BP) located adjacent to a steep escarpment with terra firme (upland) rainforest above and lateral to floodplain forests. This was followed by the development of marsh (820–640 cal yr BP). A closed-canopy Mauritia flexuosa -dominated palm swamp was subsequently established (640300calyr BP) which later changed into an open canopy and mixed Mauritia - Hedyosmum palm swamp (300 cal yr BP to present). Two major changes in peat and C accumulation rates were observed: (1) onset of peat and C accumulation at 820 cal yr BP and (2) decrease of peat and C accumulation after 520 cal yr BP. Comparisons of our results with palaeoecological records from aguajales in northern Peru suggest that the dynamics were different in this region. The peat and C accumulation rates in our study core in southern Peru were ca. 4 mm yr −1 and ca. 200 g m −2 yr −1 faster, similar to a few sites in northern Peru. Aguajales in Madre de Dios region in southern Peru are an important carbon sink. Analyzing the dynamics of aguajales which are a kind of typical peatlands in Amazonia and comparing among different sites allows exploration and prediction of regional peatlands' development under the potential future impact of natural changes. • First study of a palm peatland ( aguajal ) development in Madre de Dios region, southern Peru • This study includes late Holocene vegetation dynamics, peat and C accumulation of the aguajal • Controlling factors in the dynamics are fluvial changes and climate • Comparisons with northern Peru suggest different vegetation succession • Peat and C accumulation rates in Madre de Dios were faster, similar to a few sites in northern Peru

A Holocene history of forest vegetation on the northern slopes of a Mediterranean mountain: the Mont Ventoux, Southeast France / Histoire holocène de la végétation forestière du versant nord d’une montagne méditerranéenne : le mont Ventoux (Vaucluse, France)

This study aims at reconstructing the late Holocene vegetation dynamics and the maximum altitudinal limit of forest trees on northern slopes of Mont Ventoux before the intense deforestation of the 12th century, in relation to natural environmental changes and anthropogenic disturbances including fire history and sylvo-pastoral practices. Six soil pits were studied out along an altitudinal transect from 925m to 1,860m a. s. l. This transect crosses the beech-fir forests in the lower elevations to open woodlands containing the prostrate hooked pine (Pinus uncinata) near the summit. The study was performed within the framework of the ecological monitoring program ORCHAMP. Pedoanthracological data (identified charcoals and their 14C ages) were further explored by numerical analyses. Charcoal was found in all pits with concentrations significantly decreasing with altitude, as does the proportion of charcoal of deciduous trees over conifers. Some woody species were found at altitudes where they are absent today, notably fir (Abies alba) at high elevations, (up to 1,860m). In contrast to fir, the beech (Fagus sylvatica) charcoals were not found beyond 1,340m, although the species currently reaches elevations as high as 1,700m a. s. l. Radiocarbon dating results suggest that the soils on northern slopes of Mont Ventoux have not been significantly eroded since at least 4,000 years ago. The period covered by the six obtained AMS 14C dates extends from the Bronze Age (oldest 14C age : 3576-3729 cal BP / 1779-1626 BCE) to the Modern Era (youngest 14C age : 346-460 cal BP / 1490-1604 CE), all pre-dating the 1860’ s reforestation projects (RTM, Restoration of Mountain Land). This preliminary pedoanthracological study proved to be promising and complementary to other palaeoecological approaches but is still insufficient to provide a complete picture of the past vegetation history of Mont Ventoux.

Late-Holocene vegetation dynamics and disturbance regimes in north Patagonia Argentina (40°S)

Natural disturbance processes such as volcanic eruptions, fire and human activities are important vegetation drivers in north Patagonia. Here, we tested the impact of volcanic ash fall and fire on vegetation composition analysing two sediment records, Lake Avutarda and Lake Bruja, located in the forest-steppe transition at 40°S. In addition, our analysis provides the first account on the history of Nothofagus alpina at its eastern distribution limits. Our results comprise the last 3000 years, indicating the persistence of the vegetation despite evident volcanic activity documented by numerous tephra layers in both records. Eleven fire episodes were identified, while redundancy analysis indicates a non-significant influence of fire activity on the vegetation. The population increase of Nothofagus alpina represents the most important change in vegetation composition in the last three millennia. We speculate that the presumed change in climate, which led to the expansion of Austrocedrus chilensis south of the study area, also caused the increase of Nothofagus alpina populations in the region.

Long-term human impact and environmental change in mid-western Ireland, with particular reference to Céide Fields – an overview

Abstract. This paper presents new palaeoecological data from north County Mayo (Co. Mayo), western Ireland, and reviews published data with a view to achieving a better understanding of the timing and nature of early farming in the region, its impact on the natural environment, and the factors, including climate change, that influenced mid- and late-Holocene vegetation dynamics and farming in the region. A long pollen profile from Glenulra, a deep basin situated within Céide Fields, and short profiles from blanket peat that overlies the prehistoric stone-wall field system provide unambiguous evidence for substantial farming, including widespread woodland clearance, in the early British and Irish Neolithic (beginning ca. 3800 BCE). This was followed by a distinct lull that lasted several centuries until farming activity resumed again, at first modestly (at ca. 2700 BCE) and then more markedly from 2350 BCE, i.e. at the Neolithic–Chalcolithic transition. It is argued on the basis of this and other palaeoecological evidence, including pollen analytical investigations at nearby Garrynagran, that, contrary to recent suggestions, there is no reason to doubt the widely held view that the stone-wall field system – unique in a western European Neolithic context – is correctly ascribable to the earlier part of the British and Irish Neolithic. The history of pine growing in bog contexts (mainly blanket bog) in the region is considered in the light of 14C dates derived from pine timbers, and the results of dendrochronological investigations at Garrynagran that have enabled two floating pine chronologies to be constructed, are presented. The climatic implications of these data are discussed within local and wider regional contexts.

Reconstruction of the mid-to Late- Holocene history of vegetation and land-use in Petrešiūnai, north-east Lithuania: Implications from palaeobotanical and archaeological data

This study presents the results of multi-proxy investigations of mid-to late-Holocene vegetation dynamics and land-use history associated with the Petrešiūnai archaeological site, north-east Lithuania. Identified vegetation changes are discussed in the context of both natural and anthropogenic factors determined within the site and its surroundings. The initial stages of colonisation and the subsequent land-use dynamics are discussed by applying the results of biostratigraphical and archaeological-historical data. To explore these issues, a lacustrine sediment core obtained from the stand-scale sedimentary basin was studied using a microbotanical (pollen and microcharcoal) survey and 14C and magnetic susceptibility (MS) measurements. Associations between proxies were statistically tested. In addition, archaeological excavations were conducted within the area of the Petrešiūnai hill fort. The results obtained show the presence of a heavily forested landscape with broad-leaved deciduous trees dominating the taxa existed in the area until approximately 4800-4700 cal BC. Low magnitude fire activity mainly caused by the natural factors was recorded. The expansion of spruce and the gradual decrease in thermophilous taxa suggests a local-scale climatic reversal started prior to the general decline of the HTM (Holocene Thermal Maximum). The decay of broad-leaved taxa followed by the pronounced culmination of Picea-dominated forest (2100-1500 cal BC) confirms the general re-organisation of the forest structure in the area. A small-scale vegetation stress, accompanied by an increase in fire interference suggestive of episodic Neolithic-Bronze Age human activity, was noted in the area at approximately 2800-2200 cal BC, 1800 cal BC and 1500 cal BC. Biostratigraphical and sedimentological data suggest agriculture practices and animal husbandry were introduced and the landscape was increasingly utilised between 1300 and 1000 cal BC, which preceded the archaeological record of the Petrešiūnai hill fort by a few hundred years. However, as indicated by pollen data, pastoral farming predominated the local economy until approximately 400 AD. The establishment of regular cultivation practices, including crop rotation, and the formation of permanent fields with introduction of winter cereals began in the surroundings of Petrešiūnai by the 6th - 7th c. AD. At that time, the secondary open Betula-dominant vegetation successions flourished in the area. A highly diversified landscape with large agriculture fields, open grounds, meadows and pastures culminated in the area between 1000 and 1300 AD. After this period, the intensity of the human-induced vegetation changes apparently decreased, which confirms re-organisation of the settlement pattern and land-use in this area.

Late-Holocene vegetation dynamics in response to a changing climate and anthropogenic influences – Insights from stratigraphic records and subfossil trees from southeast Lithuania

To increase our understanding of long-term climate dynamics and its effects on different ecosystems, palaeoclimatic and long-term botanical reconstructions need to be improved, in particular in underutilized geographical regions. In this study, vegetation, (hydro)climate, and land-use changes were documented at two southeast Lithuanian peatland complexes – Čepkeliai and Rieznyčia – for the Late-Holocene period. The documentation was based on a combination of pollen, plant macrofossils, peat stratigraphic records, and subfossil trees. Our results cover the last two millennia and reveal the existence of moist conditions in Southern Lithuania between 300 and 500 CE and from 950 to 1850 CE. Conversely, changes towards warmer and/or dryer conditions have been recorded in 100, 600, and 750 CE, and since the 1850s. Significant differences with other Baltic proxies prevent deriving a complete and precise long-term reconstruction of past hydroclimatic variability at the regional scale. Yet, our results provide an important cornerstone for an improved understanding of regional climate change, i.e. in a region for which only (i) few detailed palaeobotanical studies exist and which has, in addition, been considered as (ii) an ecologically sensitive region at the interface between the temperate and boreal bioclimatic zones.

Late Holocene vegetation dynamics and human impact in the catchment basin of the Upper Oka River (Mid-Russian Uplands): A case study from the Orlovskoye Polesye National Park

Using the territory of the Orlovskoye Polesye National Park as a case study within the catchment basin of the Oka River (Mid-Russian Uplands, Oryol Region, Russia), we obtained palaeoecological data for studying response of forest landscapes within the forest-steppe ecotone to climate change and human impact through the Late Holocene. The paper presents reconstruction of environmental change on a local to regional scales based on plant macrofossil, spore-pollen and testate amoeba records from a peat core along with reconstruction of woodland coverage inferred from pollen data. Over the past 4000 years, the total woodland coverage has fluctuated insignificantly, ranging from 38 to 52%, while the structure of the forest has changed radically. Prior to 1500 cal. yr BP, both birch-pine and mixed temperate deciduous forests of oak, elm, ash and lime with Scots pine and well-developed shrub understory of hazel and alder grew in the region. The subsequent agricultural colonization of the territory led to a reduction of a broadleaved trees in forest stands since 1500 cal. yr BP. During the last few centuries, human activity largely associated with cutting/burning trees and farming favored the expansion of secondary forests dominated by birch.

Mid- and Late Holocene vegetation dynamics and fire history in the boreal forest of European Russia: A case study from Meshchera Lowlands

Climate, fire, and human activities strongly affected the development of vegetation communities during the Holocene, yet the relative importance of these individual factors remains unclear in many areas. This paper presents new multi-proxy records of environmental change for the Meshchera Lowlands (the central part of the East European Plain) during the Holocene. Changes in regional vegetation during the Mid- and Late Holocene were influenced by climate, fire regime and human impact, as indicated by pollen, plant macrofossil, charcoal and testate amoebae analysis from several peat cores, along with reconstruction of tree cover from pollen assemblages. Since 8500calyrBP, the vegetation history represented a series of consecutive phases of birch, birch-pine and pine-broadleaf forests, with introduction of spruce after 2500calyrBP. Maximal abundance of broadleaf tree species was detected from 4700 to 2000calyrBP. Vegetation dynamics were strongly influenced by human activity since 1400calyrBP. High fire frequency was recorded for the periods 8500–4500calyrBP and 3500–2000calyrBP, when the fire return interval varied from 40 to 80years. Since 2000calyrBP, the fire return period exceeded 500years suggesting a significant decline in fire frequency during the last two millennia.

Late Holocene vegetation dynamics and deforestation in Rano Aroi: Implications for Easter Island's ecological and cultural history

Easter Island (Rapa Nui) has been considered an example of how societies can cause their own destruction through the overexploitation of natural resources. The flagship of this ecocidal paradigm is the supposed abrupt, island-wide deforestation that occurred about one millennium ago, a few centuries after the arrival of Polynesian settlers to the island. Other hypotheses attribute the forest demise to different causes such as fruit consumption by rats or aridity but the occurrence of an abrupt, island-wide deforestation during the last millennium has become paradigmatic in Rapa Nui. We argue that such a view can be questioned, as it is based on the palynological study of incomplete records, owing to the existence of major sedimentary gaps. Here, we present a multiproxy (pollen, charcoal and geochemistry) study of the Aroi core, the first gap-free sedimentary sequence of the last millennia obtained to date in the island. Our results show changing vegetation patterns under the action of either climatic or anthropogenic drivers, or both, depending on the time interval considered. Palm forests were present in Aroi until the 16th century, when deforestation started, coinciding with fire exacerbation –likely of human origin– and a dry climate. This is the latest deforestation event recorded so far in the island and took place roughly a century before European contact. In comparison to other Easter Island records, this record shows that deforestation was neither simultaneous nor proceeded at the same pace over the whole island. These findings suggest that Easter Island's deforestation was a heterogeneous process in space and time, and highlights the relevance of local catchment traits in the island's environmental and land management history.

High-resolution pollen record from Efate Island, central Vanuatu: Highlighting climatic and human influences on Late Holocene vegetation dynamics

Climate changes, sea-level variations, volcanism and human activity have influenced the environment of the southwest Pacific Islands during the Holocene. The high-resolution palynological analysis presented here concerns two specific levels (main lithological changes) of a well-dated Holocene core, Tfer06, collected from Emaotfer Swamp, Efate Island (Vanuatu). Our aim is to understand the role of climatic variability and human activities in shaping vegetation during these changes. Between 3790–3600cal yr BP, the development of vegetation marked by disturbance is a marker of an increase in sustained El Niño events, also observed in many Asian-West Pacific areas. Between 1500–900cal yr BP, the increase in introduced taxa and in microcharcoal particles is interpreted as human impact. In a forthcoming paper, the ongoing high-resolution palynological analysis of the whole core will be compared and integrated into regional palaeoecological data.

Vegetation history of the western Rif mountains (NW Morocco): origin, late-Holocene dynamics and human impact

Unlike southern Spain, northern Morocco has been little investigated for palaeoecological purposes. Consequently, the origin and history of the Rifan vegetation is largely unknown, as well as the past role of human activities. A review of the Plio-Pleistocene fossil data available from North Africa clearly reveals the ancient origin of much of the present-day flora and vegetation structures of the region. A well-dated pollen record covering the last 5,000 years, obtained from a fen, is compared to previous regional pollen data in order to understand the late-Holocene vegetation dynamics and the influence of anthropogenic disturbances. Modern pollen spectra have allowed the calibration of pollen diversity and evenness as indicators of tree-cover density. The results obtained show the long-term persistence of regional forests until the onset of Arab Sharifian dynasties in the 16th century, with a surprising lack of human impact during the late Neolithic, and little impact during Roman colonisation. The increasing density of deciduous forests recorded from 3,800 to 1,900 cal bp, concomitant with the expansion of cedar in the Middle Atlas, could reveal the onset of widespread cooler and moister climatic conditions. The weak and late human impact in the Rifan mountains explains, at least in part, their high diversity and the conservation of their forest ecosystems. Anthropogenic activities however have led to severe modification of the understorey structure of these forests during the four last centuries, and to the worrying on-going deforestation that presently threatens the survival of this invaluable biological heritage.

17. Lake Skakavitsa (Bulgaria): Late Holocene vegetation dynamics in north-western Rila Mountains

17. Lake Skakavitsa (Bulgaria): Late Holocene vegetation dynamics in north-western Rila Mountains

Late Holocene vegetation dynamics of the Virunga Volcanoes of South-western Uganda: Evidence from Phytolith analysis

Late Holocene vegetation dynamics of the Virunga Volcanoes of South-western Uganda: Evidence from Phytolith analysis

A mid- to late-Holocene Vegetation Dynamics in Lake Victoria Basin: Evidence from Phytolith Analysis

A mid- to late-Holocene Vegetation Dynamics in Lake Victoria Basin: Evidence from Phytolith Analysis

Vegetation dynamics around Lake Baikal since the middle Holocene reconstructed from the pollen and botanical composition analyses of peat sediments: Implications for paleoclimatic and archeological research

The present paper summarizes the current evidence of natural changes in the forest and forest-steppe areas of the Lake Baikal Region (LBR) since ca. 7 cal ka BP, covering the period from the late Neolithic to the present time. To reconstruct local to small-regional scale vegetation changes and their probable causes during this period, pollen content and peat botanical composition were analyzed from three radiocarbon-dated peat sections, located near Lake Baikal. For better understanding of the local and regional environmental history and climate variability during the middle and late Holocene, the results are compared with published environmental records from lacustrine and mire sediments from the LBR and from elsewhere. The comparison confirms the earlier interpretations that the middle and late Holocene vegetation dynamics in the LBR was primarily driven by natural forcing and likely was associated with large-scale circulation processes controlling the regional water balance rather than with human activities. Some synchronous changes in environmental and archeological data likely point to a possible causal link between past climate changes and the cultural history of the region. The Kuchelga (53°00′57″N, 106°44′49″E), Ochkovoe (51°26′05″N, 104°38′57″E) and Cheremushka (52°45′09″N, 108°05′50″E) peat records represent three different climatic regions around Lake Baikal and demonstrate that the environments and vegetation of the drier western coast were more sensitive to the climate oscillations of the middle and late Holocene in comparison to the more humid areas east, and particularly south of Baikal. Therefore, it could be expected that environmental impact on early human societies was strongest in the arid region to the west of Lake Baikal. To test this hypothesis, however, accurately dated multi-proxy records of the Holocene climate and environments from this so far poorly studied region are absolutely necessary.