Millennial-scale vegetation changes in the north-eastern Russian
Arctic during the Pliocene/Pleistocene transition (2.7e2.5 Ma) inferred
from the pollen record of Lake El’gygytgyn
Andrei A. Andreev a, b, *
, Pavel E. Tarasov c
, Volker Wennrich a
, Martin Melles a
a
Institute of Geology and Mineralogy, University of Cologne, Zülpicher Str. 49a, 50674 Cologne, Germany
b
Institute of Geology and Petroleum Technologies, Kazan Federal University, Kremlyovskaya Str. 18, 420008 Kazan, Russia
c
Free University Berlin, Institute of Geological Sciences, Palaeontology, Malteserstr. 74-100, Building D, 12249 Berlin, Germany
a r t i c l e i n f o
Article history:
Received 31 March 2015
Received in revised form
19 February 2016
Accepted 22 March 2016
Available online xxx
Keywords:
Pollen record
Pliocene/Pleistocene transition
North-easter Russian Arctic
Lake El’gygytgyn
a b s t r a c t
The sediment record of Lake El’gygytgyn (67
300
N, 172
050
E) spans the past 3.6 Ma and provides unique
opportunities for qualitative and quantitative reconstructions of the regional paleoenvironmental history
of the terrestrial Arctic. Millennial-scale pollen studies of the sediments that accumulated during the Late
Pliocene and Early Pleistocene (ca. 2.7 to 2.5 Ma) demonstrate orbitally-driven vegetation and climate
changes during this transitional interval. Pollen spectra show a significant vegetation shift at the Pliocene/Pleistocene
boundary that is, however, delayed by a few thousand years compared to lacustrine
response. About 2.70e2.68 Ma the vegetation at Lake El’gygytgyn, currently a tundra area was mostly
dominated by larch forests with some shrub pine, shrub alder and dwarf birch in understory. During the
marine isotope stages G3 and G1, ca. 2.665e2.647 and 2.625e2.617 Ma, some spruce trees grew in the
local larch-pine forests, pointing to relatively warm climate conditions. At the beginning of the Pleistocene,
around 2.588 Ma, a prominent climatic deterioration led to a change from larch-dominated
forests to predominantly treeless steppe- and tundra-like habitats. Between ca. 2.56e2.53 Ma some
climate amelioration is reflected by the higher presence of coniferous taxa (mostly pine and larch, but
probably also spruce) in the area. After 2.53 Ma a relatively cold and dry climate became dominant again,
leading to open steppe-like and shrubby environments followed by climate amelioration between ca.
2.510 and 2.495 Ma, when pollen assemblages show that larch forests with dwarf birch and shrub alder
still grew in the lake’s vicinity. Increased contents of green algae colonies (Botryococcus) remains and
Zygnema cysts around 2.691e2.689, 2.679e2.677, 2.601e2.594, 2.564e2.545, and 2.532e2.510 Ma suggest
a spread of shallow-water environments most likely due to a lake-level lowering. These events
occurred simultaneously with dry climate conditions inferred from broad distribution of steppe habitats
with Artemisia and other herbs.
© 2016 Elsevier Ltd. All rights reserved.
1. Introduction
The transition from the late Pliocene into the earliest Pleistocene
is an interval of dynamic environmental changes. During this
transition glacioeustatic sea-level changes markedly increased in
amplitude in response to intensification and increased fluctuation
of Northern Hemisphere glaciation (Bailey et al., 2012). Generally,
this interval at about 2.588 Ma covers the termination of the
Pliocene, the most recent geological epoch with global temperatures
several degrees higher than today, and the onset of the
Pleistocene, the epoch of increasing climate extremes.
The high Arctic is particularly sensitive to climate changes.
Recent studies have shown that during the last few decades the
Arctic has experienced significant warming, more dramatic than in
other parts of the globe (e.g. Sundqvist et al., 2010 and references
therein). The rate of temperature increase of 2 C since 1961
significantly exceeds that of the global mean (IPCC, 2007). With
further temperature rise, the permafrost-dominated Siberian Arctic
will likely turn from a main methane sink into a significant source
of greenhouse gases (e.g. Schuur et al., 2009; Nisbet et al., 2014).
* Corresponding author. Institute of Geology and Mineralogy, University of Cologne,
Zülpicher Str. 49a, 50674 Cologne, Germany.
E-mail address: aandreev@uni-koeln.de (A.A. Andreev).
Contents lists available at ScienceDirect
Quaternary Science Reviews
journal homepage: www.elsevier.com/locate/quascirev
http://dx.doi.org/10.1016/j.quascirev.2016.03.030
0277-3791/© 2016 Elsevier Ltd. All rights reserved.
Quaternary Science Reviews xxx (2016) 1e14
Please cite this article in press as: Andreev, A.A., et al., Millennial-scale vegetation changes in the north-eastern Russian Arctic during the
Pliocene/Pleistocene transition (2.7e2.5 Ma) inferred from the pollen record of Lake El’gygytgyn, Quaternary Science Reviews (2016), http://
dx.doi.org/10.1016/j.quascirev.2016.03.030
For a better understanding of climate and environmental processes
in the Arctic long, high-resolution paleoenvironmental records
are required. Such records are also an important prerequisite
for the validation and improvement of climate simulation scenarios.
Unfortunately, long-term, continuous records are extremely
rare in the Arctic. It took until 2009 for the first terrestrial sediment
record that continuously penetrates beyond the Pliocene/Pleistocene
boundary to become available from Lake El’gygytgyn, which
was drilled under the auspices of the International Continental
Scientific Drilling Program (ICDP) (Melles et al., 2011, 2012;
Brigham-Grette et al., 2013).
Lake El’gygytgyn was formed following a meteorite impact
3.58 ± 0.04 Ma ago (Layer, 2000), in an area of northeastern Russia
that remained afterwards free of continental glaciations, despite its
location approximately 100 km to the north of the Arctic Circle
(67300N, 172050E, Fig. 1). The unique, 318-m thick, sedimentary
record of Lake El’gygytgyn provides excellent opportunities for
time-continuous reconstructions of past environments. Multiproxy
results from the upper part (back to 2.8 Ma) of the lake
sediment succession have provided a complete record of glacial/
interglacial changes in the Arctic throughout the Pleistocene
(Melles et al., 2012). A first compilation of data and paleoenvironmental
interpretations obtained from the lower part of the record
(~3.6e~2.2 Ma ago) was published by Brigham-Grette et al.
(2013). More detailed results have recently become available in a
special issue of the journal Climate of the Past: Initial results from
Lake El’gygytgyn, western Beringia: first time-continuous PliocenePleistocene
terrestrial record from the Arctic (http://www.clim-past.
net/special_issue48.html).
Amongst the large number of sediment proxies applied to the
El’gygytgyn record, palynological proxies turned out to be of
particular importance (Melles et al., 2012; Andreev et al., 2012,
2014; Brigham-Grette et al., 2013; Lozhkin and Anderson, 2013;
Tarasov et al., 2013). Modern pollen studies indicate that the lake
record provides reliable insights into regional and/or even overregional
vegetation changes, since the lake traps pollen from a
source area of several thousand square-kilometers (Lozhkin and
Anderson, 2013 and references therein). Taking the sensitivity of
the vegetation to climate, the pollen assemblages can also be used
to reconstruct climate parameters and to validate and improve
climate model scenarios.
According to initial palynological results, the Pliocene/Pleistocene
boundary (at 2.558 Ma during Marine Isotope Stage (MIS 103)
marks an important change in vegetation at Lake El’gygytgyn from
generally interglacial to glacial environmental conditions (Andreev
et al., 2014). However, the understanding of the vegetation and
climate change at this globally important boundary was hampered
by the rather low temporal resolution of ca. 2000 yr/sample of the
preliminary palynological data. Here, we present a more detailed
reconstruction of climatically and environmentally driven vegetation
changes in the northeastern Russian Arctic between ~2.7 and
~2.5 Ma, based upon palynological data from the Lake El’gygytgyn
record in a temporal resolution of ca. 800 yr/sample in average.
Fig. 1. Map of Lake El’gygytgyn showing the location of ICDP Site in the central, deepest part of the lake (for location of the lake in north-eastern Russia see inserted map).
A.A. Andreev et al. / Quaternary Science Reviews xxx (2016) 1e142
Please cite this article in press as: Andreev, A.A., et al., Millennial-scale vegetation changes in the north-eastern Russian Arctic during the
Pliocene/Pleistocene transition (2.7e2.5 Ma) inferred from the pollen record of Lake El’gygytgyn, Quaternary Science Reviews (2016), http://
dx.doi.org/10.1016/j.quascirev.2016.03.030
2. Lake setting
Lake El’gygytgyn is located in a meteorite impact crater of 18 km
in diameter, which was formed about 3.58 Ma ago in an Upper
Cretaceous volcanic plateau in NE Russia (Layer, 2000, Fig. 1). Today
the 170-m deep and 12 km wide lake covers an area of 110 km2
within a 293 km2
large catchment that is defined by the crater rim
comprising peaks between 600 and 930 m above sea level (a.s.l.).
The modern lake level is situated at 492 m a.s.l.
The region is characterized by an extremely harsh climate with
mean annual air temperatures of ca. À10 C, mean July temperatures
of 4e8 C and mean January temperatures of À32 to À36 C.
The precipitation consists of 70 mm summer rainfall (JuneeSeptember)
and ca. 110 mm water equivalent of snowfall (Nolan and
Brigham-Grette, 2007). The local climate variables are strongly
dependent on oceanic influence, as expressed in relatively low
summer temperatures (Kozhevnikov, 1993). Predominant wind
directions at Lake El’gygytgyn are from the south and north. The
study area is located in the zone of continuous permafrost with a
mean annual ground temperature of À10 C at 12.5 m below the
ground surface (Schwamborn et al., 2008).
The study area belongs to the subzone of southern shrub and
typical tundra. The modern treeline for larch and shrub stone pine
is positioned roughly 100 km to the south and west of the lake. Only
dwarf birches and willow grow in the lake vicinity. Although the
northern boundary of shrub alder is reported to be located further
to the north of the lake, the only few shrub alder stands grow
approximately 10 km from the lake, in the more protected river
valley habitats (Andreev et al., 2012; Lozhkin and Anderson, 2013
and references therein). For a more detailed description of the
local vegetation see Belikovich and Galanin (1994), Andreev et al.
(2014) and references therein.
Recent pollen assemblages from the sediments of Lake El’gygytgyn
contain significant amounts of tree and shrub pollen grains
that have been transported to the lake by air over long distances
(Lozhkin et al., 2001; Matrosova et al., 2004; Matrosova, 2006,
2009; Andreev et al., 2012; Lozhkin and Anderson, 2013). Hence,
for interpretations of fossil pollen assemblages it has to be taken
into consideration that parts of the pollen may have originated
from dozens, or for some rare pollen types perhaps hundreds, of
kilometers away.
3. Material and methods
Drilling at ICDP site 5011-1 in central Lake El’gygytgyn (Fig. 1)
was conducted in spring 2009 using the lake ice as a platform (for
details see Melles et al., 2011). The 318-m long composite record
retrieved from the lacustrine sediments overlaying impact rocks
represents the complete history following lake formation soon after
the impact event ~3.6 Ma ago. The record was investigated using
non-destructive scanning and logging techniques along with multiproxy
investigations on discrete subsamples (for details see Melles
et al., 2012; Brigham-Grette et al., 2013 and papers in a special issue
of Climate of the Past). The age model for the record is primarily
based on paleomagnetic stratigraphy and subsequent cyclostratigraphy
of various climatically-controlled sedimentological
and geochemical parameters. As the time interval presented in this
paper includes the paleomagnetic Gauss/Matuyama polarity
change at 2.588 Ma (Nowaczyk et al., 2013) the age model is well
constrained for the Pliocene/Pleistocene transition. Further details
can be found in Haltia and Nowaczyk (2014) and Nowaczyk et al.
(2013).
Pollen subsamples of ca. 1 g were investigated in the composite
depth from 130.57 to 117.66 m below lake floor corresponding to
the time interval from ~2.7 to ~2.5 Ma at a resolution of about 0.8
kyr or higher. The samples were processed following a standard HF
technique for pollen preparation (Berglund and RalskaJasiewiczowa,
1986). The procedure includes KOH, HCl, HF, and
acetolysis treatments as well as fine sieving (112 mm) to remove
clay-sized particles. A tablet of Lycopodium marker spores was
added to each sample for calculating total pollen and spore concentrations
following Stockmarr (1971). Glycerol was used for
sample storage and preparation of the microscopic slides. Pollen
and spores were identified under a light microscope at 400Â
magnification, with the aid of published pollen keys and atlases
(e.g., Kupriyanova and Alyoshina, 1978; Bobrov et al., 1983; Reille,
1992, 1995, 1998). Non-pollen-palynomorphs (NPPs), such as
fungi spores, remains of algae and invertebrate, were also identified
and counted when possible following van Geel (2001 and references
therein).
At least 250 pollen grains of terrestrial plants were counted in
each sample. Exceptions are samples with extremely low pollen
concentration, in which the number of counted pollen grains might
be less. Such samples were excluded from the paleoenvironmental
reconstructions or only used with special precaution. The relative
frequencies of pollen taxa were calculated from the sum of the
terrestrial pollen taxa. Spore percentages are based on the sum of
pollen and spores. The percentages of non-pollen palynomorphs
are based on the sum of the pollen and non-pollen palynomorphs,
and the percentages of algae are based on the sum of pollen and
algae. The TGView software (Grimm, 2004) was used for the
calculation of percentages and for drawing the diagrams (Fig. 2a-b).
Adobe Illustrator software was used for the compilation of the final
pollen diagrams.
Pollen-based biome reconstruction (also known as the ‘biomization’
approach), using the numerical method first introduced
by Prentice et al. (1996), facilitates interpretation of pollen data and
data-model comparison (e.g., Brigham-Grette et al., 2013). This
approach assigns identified pollen taxa to principal vegetation
types (biomes) on the basis of the modern ecology, bioclimatic
tolerance and spatial distribution of pollen-producing plants. The
method was successfully tested using extensive surface pollen data
sets and regionally adapted biome-taxa matrixes from northern
Eurasia (Tarasov et al., 1998; Edwards et al., 2000), and applied to
the last glacial-interglacial pollen records from the vast regions of
Siberia and the Far East (e.g. Tarasov et al., 1998, 2000; 2005;
Edwards et al., 2000; Mokhova et al., 2009; Müller et al., 2010). It
was also applied to lower-resolution Lake El’gygytgyn pollen records
(Melles et al., 2012; Brigham-Grette et al., 2013; Tarasov et al.,
2013) using the same biome-taxon matrix as in this study.
The biome-taxon matrix (Table 1) was constructed using all
identified terrestrial pollen taxa assigned to the main vegetation
types found in Siberia and the Far East regions. The biome score
calculation was performed using standard equation and reconstruction
procedures published by Prentice et al. (1996) and
PPPBase software (Guiot and Goeury, 1996). Square root transformation
was applied to the pollen percentage values to increase
the importance of the minor pollen taxa and the 0.5% threshold was
universally used as suggested by Prentice et al. (1996). The biome
with the highest affinity score or the one defined by a smaller
number of taxa/plant functional types (when scores of several biomes
are equal) was assigned for each pollen spectrum as the
dominant biome (Fig. 3).
Bigelow et al. (2003) suggested an alternative biome-taxon
matrix and modified biomization approach in an attempt to
refine reconstructions of different types of tundra (Table 1) and to
get closer to the real vegetation described in botanical literature
and to the BIOME4 model output (Kaplan, 2001). Their approach
differs in some principal aspects from the original biomization
procedure published by Prentice et al. (1996) and accepted in the
A.A. Andreev et al. / Quaternary Science Reviews xxx (2016) 1e14 3
Please cite this article in press as: Andreev, A.A., et al., Millennial-scale vegetation changes in the north-eastern Russian Arctic during the
Pliocene/Pleistocene transition (2.7e2.5 Ma) inferred from the pollen record of Lake El’gygytgyn, Quaternary Science Reviews (2016), http://
dx.doi.org/10.1016/j.quascirev.2016.03.030
Fig. 2. Percentage pollen, spore, and non-pollen-palynomorph diagram for the time interval ca. 2.7 to 2.5 Ma of the Lake El’gygytgyn sediment record, showing A) the most
common pollen, spores and non-pollen-palynomorphs types and B) the minor pollen, spores and non-pollen-palynomorphs types.
A.A. Andreev et al. / Quaternary Science Reviews xxx (2016) 1e144
Please cite this article in press as: Andreev, A.A., et al., Millennial-scale vegetation changes in the north-eastern Russian Arctic during the
Pliocene/Pleistocene transition (2.7e2.5 Ma) inferred from the pollen record of Lake El’gygytgyn, Quaternary Science Reviews (2016), http://
dx.doi.org/10.1016/j.quascirev.2016.03.030
Fig. 2. (continued).
A.A. Andreev et al. / Quaternary Science Reviews xxx (2016) 1e14 5
Please cite this article in press as: Andreev, A.A., et al., Millennial-scale vegetation changes in the north-eastern Russian Arctic during the
Pliocene/Pleistocene transition (2.7e2.5 Ma) inferred from the pollen record of Lake El’gygytgyn, Quaternary Science Reviews (2016), http://
dx.doi.org/10.1016/j.quascirev.2016.03.030
following publications on northern Eurasia related to the
BIOME6000 project (e.g., Tarasov et al., 1998, 2000). In order to
compare our results with those of Bigelow et al. (2003), we applied
their taxa to biome assignment (Table 1) and biome reconstruction
steps to the Lake El’gygytgyn pollen record presented in this paper.
Both result sets are discussed in section 4.8.
4. Results
A total of 259 samples have been investigated from the Pliocene/
Pleistocene transition between 130.57 m (~2.7 Ma) and 117.66 m
(~2.5 Ma) depth of the composite core from ICDP site 5011-1 in the
center of Lake El’gygytgyn (Fig. 1). Almost 120 different pollen,
spore, and non-pollen-palynomorph types have been found in the
studied samples (Fig. 2). The most important pollen, spore, and
non-pollen-palynomorph types are presented on Fig. 2a, the minor
types on Fig. 2b. The revealed pollen assemblages can be subdivided
into 22 main pollen zones (PZ), based upon a qualitative
inspection of significant changes in pollen associations, pollen
concentrations, and on the occurrence of particularly indicative
taxa. PZ-I (ca. 2.702e2.698 Ma) shows high Betula and Cyperaceae
pollen contents, while Pinus pollen is almost absent. This zone is
also characterized by rather high contents of fungi spores (mainly
Gelasinospora and Sordaria). Pollen concentration reaches 9750
grains/g.
PZ-II (ca. 2.698e2.692 Ma) is noticeable by a significant increase
in Pinus (up to 38%) and Larix (up to 20%) pollen contents, while
Cyperaceae pollen are drastically decreased. Sordaria spore contents
also show an increase. Pollen concentration is slightly higher
(up to 12,840 grains/g) than in PZ-I.
PZ-III (ca. 2.692e2.684 Ma) is characterized by a significant
decrease in coniferous and Alnus pollen, while Artemisia, Poaceae,
and Cyperaceae pollen drastically increase. The zone is also
noticeable for the relatively high presence of Botryococcus green
algae colonies and Zygnema cysts. Pollen concentration is lower (up
to 6090 grains/g) than in PZ-II.
Significant increases in Pinus (up to 40%), Larix (up to 18%), and
Alnus (up to 22%) pollen are characteristic for PZ-IV (ca.
2.684e2.679 Ma). Pollen concentration in this zone is significantly
higher (up to 27,240 grains/g) than in PZ-III.
In PZ-V (ca. 2.679e2.672 Ma) coniferous pollen contents gradually
decrease, while Artemisia, Poaceae, and Cyperaceae pollen
and Selaginella spore contents increase. The zone is also noticeable
for the rather high presence of Botryococcus green algae colonies
and Zygnema cysts. Pollen concentration is much lower (up to 2340
grains/g) than in PZ-IV.
In PZ-VI (ca. 2.672e2.665 Ma) Pinus pollen is almost absent,
while Betula and Cyperaceae pollen and Sphagnum spores are
Table 1
Biome-taxon matrixes used in the biome reconstructions. All terrestrial pollen taxa identified in the fossil pollen spectra from the analyzed core are attributed to one or several
potentially present biomes.
Biome name Abbr. Attributed pollen taxa
After Tarasov et al. (2013)/Brigham-Grette et al. (2013)
Tundra TUND Alnus fruticosa-type (shrub), Betula sect. Albae-type (tree), B. sect. Nanae-type (shrub), B.
undif., Cyperaceae, Ericales, Poaceae, Polemonium, Polygonum bistorta-type, Rubus chamaemorus, Rumex, Salix, Saxifragaceae,
Valerianaceae
Cold deciduous forest CLDE Alnus fruticosa-type (shrub), A. sp. (tree), Betula sect. Albae-type (tree), B. sect. Nanae-type (shrub), B. undif., Cupressaceae/
Taxodiaceae, Ericales, Larix/Pseudotsuga, Pinus s/g Diploxylon, P. s/g Haploxylon, Pinaceae undif., Populus, Rubus chamaemorus,
Salix
Taiga TAIG Abies, Alnus sp. (tree), Betula sect. Albae-type (tree), B. sect. Nanae-type (shrub) B. undif., Cupressaceae/Taxodiaceae, Ericales,
Larix/Pseudotsuga, Lonicera, Picea, Pinus s/g Diploxylon, P. s/g Haploxylon, Pinaceae undif., Populus, Rubus chamaemorus, Salix
Cool conifer forest COCO Abies, Alnus sp. (tree), Betula sect. Albae-type (tree), B. sect. Nanae-type (shrub), B. undif., Carpinus-type, Corylus, Cupressaceae/
Taxodiaceae, Ericales, Larix/Pseudotsuga, Lonicera, Picea, Pinus s/g Diploxylon, P. s/g Haploxylon, Pinaceae undif., Populus, Salix,
Tilia, Tsuga, Ulmus
Temperate deciduous forest TEDE Abies, Alnus sp. (tree), Betula sect. Albae-type (tree), B. sect. Nanae-type (shrub), B. undif., Carpinus-type, Carya, Corylus,
Cupressaceae/Taxodiaceae, Ericales, Juglans, Larix/Pseudotsuga, Lonicera-type, Pinus s/g Diploxylon, Pinaceae undif., Populus,
Pterocarya, Quercus deciduous, Salix, Tilia, Ulmus
Cool mixed forest COMX Abies, Alnus sp. (tree), Betula sect. Albae-type (tree), B. sect. Nanae-type (shrub), B. undif., Carpinus-type, Corylus, Cupressaceae/
Taxodiaceae, Ericales, Larix/Pseudotsuga, Lonicera- type, Picea, Pinus s/g Diploxylon, P. s/g Haploxylon, Pinaceae undif., Populus,
Tsuga, Quercus deciduous, Salix, Tilia, Ulmus
Warm mixed forest WAMX Alnus sp. (tree), Carpinus-type, Carya, Corylus, Cupressaceae/Taxodiaceae, Ericales, Juglans, Lonicera, Pinus subgenus Diploxylon,
Pinaceae undif., Populus, Pterocarya, Quercus deciduous, Salix, Tilia, Ulmus
Cold steppe COST Apiaceae, Artemisia, Asteraceae Asteroideae, Asteraceae Cichorioideae, Brassicaceae, Cannabis-type, Caryophyllaceae,
Chenopodiaceae, Fabaceae, Lamiaceae, Linum, Onagraceae, Papaveraceae, Plantaginaceae, Poaceae, Polygonum bistorta-type,
Ranunculaceae, Rosaceae, Rumex, Sanguisorba, Thalictrum, Urticaceae, Valerianaceae
After Bigelow et al. (2003)
Temperate grassland and
xerophytic shrubland
STEP Apiaceae, Artemisia, Asteraceae undif., Brassicaceae, Caryophyllaceae, Chenopodiaceae, Gentianaceae, Lamiaceae,
Papaveraceae, Plantaginaceae, Poaceae, Ranunculaceae, Rosaceae, Rumex, Sanguisorba, Thalictrum, Valerianaceae
Cushion-forb tundra CUSH Apiaceae, Artemisia, Asteraceae undif., Brassicaceae, Caryophyllaceae, Epilobium, Gentianaceae, Papaveraceae, Plantaginaceae,
Poaceae, Polemoniaceae, Polygonum bistorta- type, Ranunculaceae, Rosaceae, Rumex, Sanguisorba, Saxifragaceae, Thalictrum,
Valerianaceae
Graminoid and forb tundra DRYT Apiaceae, Artemisia, Asteraceae undif., Brassicaceae, Caryophyllaceae, Cyperaceae, Epilobium, Gentianaceae, Papaveraceae,
Plantaginaceae, Poaceae, Polemoniaceae, Polygonum bistorta-type, Ranunculaceae, Rosaceae, Rumex, Sanguisorba,
Saxifragaceae, Thalictrum, Valerianaceae
Prostrate dwarf- shrub tundra PROS Apiaceae, Artemisia, Asteraceae undif., Brassicaceae, Caryophyllaceae, EPILOBIUM Epilobium, Gentianaceae, Papaveraceae,
Plantaginaceae, Poaceae, Polemoniaceae, Polygonum bistorta-type, Ranunculaceae, Rosaceae, Rumex, Salix, Sanguisorba,
Saxifragaceae, Thalictrum, Valerianaceae
Erect dwarf- shrub tundra DWAR Betula sect. Nanae-type (shrub), B. undif., Cyperaceae, Ericales, Poaceae, Salix
Low- and high- shrub tundra SHRU Alnus fruticosa-type (shrub), Betula sect. Nanae-type (shrub), B. undif., Cyperaceae, Ericales, Juniperus, Pinus undif., Rubus
chamaemorus, Rumex, Salix, Sphagnum
Cold deciduous forest CLDE Alnus fruticosa-type (shrub), A. sp. (tree), Betula sect. Albae-type (tree), B. sect. Nanae-type (shrub), B. undif., Corylus, Ericales,
Juniperus, Larix, Maica, Pinus undif., Populus, Rubus chamaemorus, Salix, Sphagnum
Cold evergreen needle-leaved
forest
TAIG Abies, Alnus fruticosa-type (shrub), A. sp. (tree), Betula sect. Albae-type (tree), B. sect. Nanae-type (shrub) B. undif., Corylus,
Ericales, Juniperus, Maica, Picea, Pinus undif., Populus, Rubus chamaemorus, Salix, Sphagnum
A.A. Andreev et al. / Quaternary Science Reviews xxx (2016) 1e146
Please cite this article in press as: Andreev, A.A., et al., Millennial-scale vegetation changes in the north-eastern Russian Arctic during the
Pliocene/Pleistocene transition (2.7e2.5 Ma) inferred from the pollen record of Lake El’gygytgyn, Quaternary Science Reviews (2016), http://
dx.doi.org/10.1016/j.quascirev.2016.03.030
drastically increased. Characteristic of this zone are rather high
contents of Larix pollen (up to 12%) and very low pollen concentrations
of mostly <1000 grains/g.
PZ-VII (ca. 2.665e2.655 Ma) is characterized by a drastic increase
in Pinus, Picea, and Larix pollen contents. Pollen concentration
of up to 98,850 grains/g is very high.
In PZ-VIII (ca. 2.655e2.646 Ma) Picea pollen contents gradually
decrease, while Betula, Artemisia, Poaceae, and Cyperaceae pollen
as well as Selaginella, Sphagnum, and Lycopodium spore contents
increase. This zone is also noticeable for the rather high presence of
Ericales, Caryophyllaceae, Ranunculaceae, Brassicaceae, and Asteraceae
pollen. Pollen concentration is lower (up to 14,500 grains/g)
than in PZ-VII.
PZ-IX (ca. 2.642e2.636 Ma) is characterized by the disappearance
of coniferous pollen, while Artemisia pollen contents increase
at the beginning of the zone and Betula in its upper part. Pollen
concentration is lower (up to 4010 grains/g) than in PZ-VIII.
PZ-X (ca. 2.636e2.626 Ma) pollen assemblages are characterized
by a drastic increase in Betula pollen contents (up to 62%). This zone
is also noticeable for gradual increases in Alnus, Larix, Pinus, and
Sphagnum contents, while Poaceae, Cyperaceae Artemisia, and
Thalictrum decrease. In addition, it is characterized by relatively
high contents of Gelasinospora, Sporormiella, and Sordaria fungi
spores. Pollen concentration reaches 15,030 grains/g in the upper
part of the zone.
PZ-XI (ca. 2.626e2.617 Ma) is distinguishable by high contents
of coniferous (Pinus, Larix) and Ericales pollen. Pollen concentration
is higher (up to 30,600 grains/g) than in PZ-X.
In PZ-XII (ca. 2.617e2.603 Ma) Pinus pollen contents gradually
decrease, while percentages of Poaceae, Cyperaceae, Caryophyllaceae,
Ericales pollen and Sphagnum spores increase.
PZ-XIII (ca. 2.603e2.595 Ma) is noticeable by the disappearance
of Larix pollen and a further decrease of Pinus and Alnus pollen
contents, while Artemisia, Poaceae, and Cyperaceae pollen and
Sphagnum spores contents increase. This zone is also characterized
by rather high presence of Botryococcus colonies and Zygnema
cysts. Pollen concentration with up to 9140 grains/g is relatively
high.
In PZ-XIV (ca. 2.595e2.588 Ma) coniferous pollen is almost absent.
Characteristic for this zone is also the low content of Alnus
pollen, while percentages of Betula and Cyperaceae remarkably
increase. Pollen concentration is rather low (up to 4750 grains/g).
PZ-XV (ca. 2.588e2.578 Ma) pollen assemblages differ from PZXIV
by peaks in Larix and Alnus pollen. Furthermore, the pollen
concentration is much higher (up to 142,650 grains/g) than in PZ-
XIV.
PZ-XVI (ca. 2.578e2.558 Ma) is noteworthy for a significant increase
in Poaceae, Cyperaceae, Ericales, Artemisia, Caryophyllaceae,
Ranunculaceae, Brassicaceae, and Asteraceae pollen and Selaginella
spores percentages. In contrast, contents of Larix and Alnus pollen
as well as the pollen concentration, drastically decrease.
Characteristic for PZ-XVII (ca. 2.558e2.553 Ma) is a distinct peak
in Larix pollen percentages, while Poaceae, Cyperaceae, and other
herbs decrease.
In PZ-XVIII (ca. 2.553e2.546 Ma) Pinus pollen contents increase
significantly once a. This zone is also noticeable for the further
increase in Larix pollen and in spores of Lycopodium and
Gelasinospora.
Pinus pollen contents are further increased in PZ-XIX (ca.
2.546e2.532 Ma), reaching a maximum of 54%. Characteristic of
this zone is also the increase in Lycopodium spore contents (up to
29%).
Coniferous pollen disappear again in PZ-XX (ca.
2.532e2.515 Ma). Additional characteristics for this zone are large
amounts of Artemisia pollen and numerous remains of Botryococcus
colonies.
PZ-XXI (ca. 2.515e2.510 Ma) is characterized by a significant
increase in Betula pollen contents (up to 56%), while Artemisia
pollen are reduced.
PZ-XXII (ca. 2.510e2.492 Ma) is notable for the significant increase
in Larix pollen and Sphagnum spore contents. Alnus pollen
percentages also show some increase. Pollen concentration is much
higher (up to 16,300 grains/g) than in PZ-XXI.
5. Discussion and interpretation
The changes revealed in the pollen and non-pollenpalynomorph
records, as well as their paleoecological significance
for the reconstruction of local and regional vegetation changes, are
discussed below, along with their possible relationship with globally
and regionally known paleoenvironmental events. Such relations,
however, are not always clearly pronounced and visible in
pollen records, for instance due to delays in vegetation response to
climate changes. For example, plants, such as Pinus pumila, might
need millennia to reach their ecologically-determined northern
distribution limit. Another possible reason is a possible discrepancy
between the age model of the Lake El’gygytgyn record and age
models developed for the individual paleoenvironmental records.
The time slices discussed in this chapter were chosen according
to the importance of the revealed pollen changes for the paleoenvironmental
reconstructions and their possible relation to
globally known events.
5.1. The biome reconstruction results: an overview and climatic
implication
Two sets of the biome reconstruction results derived from the
Lake El’gygytgyn pollen record are presented in Fig. 3A. The two
approaches differ from each other in several aspects, including
tundra biome classification, taxon to biome assignment (for
example, Larix and Corylus), involvement of Sphagnum spores (for
details see Table 1), and a number of steps for the biome score
calculations. Despite the differences in approach, the results obtained
demonstrate basically the same set of the dominant biomes
and the predominance of the cold deciduous forest biome during
the investigated time interval.
The taiga biome characterized by a presence of boreal evergreen
and deciduous tree and shrub taxa appears only once in the
reconstruction based on the Bigelow et al. (2003) approach (Fig. 3A,
right panel) and a few more times in the reconstruction based on
the Tarasov et al. (2013)/Brigham-Grette et al. (2013) approach
(Fig. 3A, left panel). According to the bioclimatic limits applied by
the BIOME family vegetation models (Prentice et al., 1992; Kaplan,
2001), the reconstruction of the taiga biome suggests the most
favorable climate conditions for the boreal evergreen conifer forest
growing, including relatively mild winter temperatures and higher
precipitation or moisture availability than required by the cold
deciduous forest biome. The relatively low landscape openness
(Fig. 3B), percentages of dark coniferous pollen (Fig. 3C), and the
relatively high pollen concentration values (Fig. 3D) revealed in the
El’gygytgyn record seem to support such interpretation.
The test of the method performance using modern surface
samples from the Arctic by Bigelow et al. (2003), has demonstrated
a relatively low percentage of correct reconstructions versus observations,
i.e., 49.4% for the CLDE and 74.2% for the TAIG biome. In
turn, the test of the biomization approach applied in the current
study using representative modern pollen sample sets from eastern
Siberia (Müller et al., 2010) and from Lake El’gygytgyn (Tarasov
et al., 2013), shows much better performance in distinguishing
cold deciduous forest from tundra and taiga vegetation in the study
A.A. Andreev et al. / Quaternary Science Reviews xxx (2016) 1e14 7
Please cite this article in press as: Andreev, A.A., et al., Millennial-scale vegetation changes in the north-eastern Russian Arctic during the
Pliocene/Pleistocene transition (2.7e2.5 Ma) inferred from the pollen record of Lake El’gygytgyn, Quaternary Science Reviews (2016), http://
dx.doi.org/10.1016/j.quascirev.2016.03.030
Fig. 3. Temporal changes in (A) dominant biomes and (B) landscape openness reconstructed from the Lake El’gygytgyn pollen record presented in Fig. 2, compared to the values of.
(C) dark coniferous (Abies, Picea, Pinus s/g Haploxylon) pollen sum, (D) total pollen concentration in the Lake El’gygytgyn pollen record (this study), (E) Si/Ti ratio, (F) paleomagnetic
polarity, and (G) global marine isotope stack (after Lisiecki and Raymo, 2005). Gray bands indicate cold MIS. For technical details of the biome score and landscape openness
A.A. Andreev et al. / Quaternary Science Reviews xxx (2016) 1e148
Please cite this article in press as: Andreev, A.A., et al., Millennial-scale vegetation changes in the north-eastern Russian Arctic during the
Pliocene/Pleistocene transition (2.7e2.5 Ma) inferred from the pollen record of Lake El’gygytgyn, Quaternary Science Reviews (2016), http://
dx.doi.org/10.1016/j.quascirev.2016.03.030
region (e.g., Lozhkin and Anderson, 2013). A weighting (Â15) of the
Larix pollen percentages prior to calculating the affinity score and
an exclusive assignment of this taxon to cold deciduous forest
(Table 1), as applied by Bigelow et al. (2003), could be a main reason
for overrepresentation of the CLDE biome in the reconstruction
from Lake El’gygytgyn (Fig. 3A, right panel).
The Bigelow et al. (2003) approach reveals the reconstruction of
two (of five potentially possible) types of tundra (Table 1), thus
allowing for a more detailed understanding of the reconstructed
vegetation and the underlying climate conditions. The graminoid
and forb tundra (i.e. DRYT ¼ dry tundra) biome is reconstructed
several times through the record (Fig. 3A, right panel), i.e., during
the relatively warm early MIS G3, and during the coldest intervals
of the MIS 104, MIS 102, and MIS 100 (Fig. 3G). This reconstruction
coincides well with the reconstruction of cold steppe (Fig. 3A, left
panel) during MIS 104 and 100, suggesting that both approaches
are able to catch phases with relatively dry environments, which
could occur in both warm and cold intervals. The fact, that the
temperate grassland and xerophytic shrubland (STEP) biome does
not appear in the reconstruction using the Bigelow et al. (2003)
approach supports our interpretation of the Pliocene/Pleistocene
transition as an interval with relatively severe boreal environments.
Low- and high-shrub tundra (SHRU) is another tundra biome
revealed by the Bigelow et al. (2003) approach (Fig. 3A, right panel).
In reality such vegetation is very close in appearance to the cold
deciduous forest and often referred to as forest-tundra. We assume
that the reconstruction of SHRU is underestimated for the reasons
explained above. On the other hand, we can be more or less
confident that most of the tundra biome reconstructions (Fig. 3A,
left panel) represent low- and high-shrub tundra, which requires
relatively moist environments and snow cover sufficient to protect
woody plants from the extreme winter frost and icy winds.
5.2. Environmental conditions 2.702e2.698 Ma
Previous pollen studies of the El’gygytgyn sediments have
revealed that 2.735 Ma ago coniferous forests started to disappear
from the regional vegetation (Andreev et al., 2014). The climatedriven
environmental changes culminated between 2.710 and
2.695 Ma, when open steppe- and tundra-like habitats dominated
the vegetation around the El’gygytgyn crater, thus implying much
drier and colder conditions. Significant climate deterioration after
ca 2.71 Ma was also reconstructed from the pollen record of Lake
Baikal, which reflects that hemlock almost disappeared from the
local vegetation (Demske et al., 2002).
The climate deterioration after ca 2.71 Ma documented in the
El’gygytgyn and Baikal pollen records coincides well with the
intensification of Northern Hemisphere Glaciation during the MIS
G6. For example, Duk-Rodkin et al. (2010) found evidence for the
build-up of regional ice caps in north-western Canada and an early
Cordilleran ice sheet around 2.74 Ma. Also the Greenland, Scandinavian
and Arctic ice sheets expanded after 2.75 Ma (e.g., Kleiven
et al., 2002; Matthiessen et al., 2009 and references therein). According
to Jansen et al. (2000) the expansion of large-scale ice
sheets in the Northern Hemisphere is reflected by a significant
increase of ice-rafted debris. Studer et al. (2012) assume that a rapid
decline in diatom opal accumulation flux in North Pacific marine
sediment cores is also associated with the development of glacial
cycles at the Pliocene/Pleistocene transition. It is also notable that
dust and disseminated volcanic ash deposition in the subarctic
Pacific increased markedly ~2.75 Ma (Bailey et al., 2011).
The higher resolution pollen record presented here very well
confirms the previously revealed paleoenvironments. The sediments
deposited in Lake El’gygytgyn between ca 2.702 and
2.698 Ma (PZ-I of Fig. 2) suggest that open shrub tundra (mostly
dwarf birch) dominated the vegetation in the lake’s vicinity. This
interpretation is supported by the biome reconstruction (Fig. 3A)
for this interval, which also reveals tundra to have the highest affinity
scores. However, relatively high percentages of Larix pollen in
the fossil assemblages point to the persistent presence of larch
around the lake. The presence of arboreal vegetation in the study
area is also indicated in the relatively small difference between the
maximum score of forest biomes and the maximum score of open
biomes (a qualitative indicator of landscape openness, Fig. 3B). High
contents of Cyperaceae pollen and Sphagnum spores imply
extended wetland habitats in the lake vicinity. Generally, the PZ-I
vegetation, corresponding with the lower part of MIS G5, is
similar to a modern forest-tundra ecotone.
Thus, our pollen data point to still relatively warm, but rather
wet climate conditions on Chukotka between ca. 2.702 and
2.698 Ma. This in a good accordance with other records which for
instance suggest the synchronous rise of western subarctic Pacific
Ocean summer sea surface temperatures (SSTs), while winter SSTs
cooled (Haug et al., 2005). The latter is hypothesized to have caused
more abundant floating ice during winter times in the subarctic
Pacific. Haug et al. (2005) suggested that the observed summer
warming extended into the autumn, providing water vapor to
northern North America, where it precipitated and accumulated as
snow, and thus triggered the intensification of Northern Hemisphere
Glaciation around 2.7 Ma ago. This interpretation is supported
by data from Europe, which suggest that a significant
Scandinavian glaciation did not occur before ca 2.7 Ma (e.g., De
Schepper et al., 2014 and references therein), and that aeolian
input of terrestrial material to the North Atlantic also drastically
increased synchronously with enhanced glaciation (Naafs et al.,
2012). A significant climate change at ~2.7 Ma is also documented
in pollen data from fluviolacustrine sediments in central China,
where the onset of dominant steppe vegetation at 2.7 Ma reflects
the change from a long-lasting warm and dry climate to cold-dry
and warm-wet oscillations responding to global glacialinterglacial
forcing (Han et al., 1997).
5.3. Environmental conditions 2.698e2.665 Ma
A significant increase in Pinus, Larix, and Alnus pollen contents
between ca. 2.698e2.692 Ma (PZ-II, Fig. 2, upper part of MIS G6,
Fig. 3G) reflects climate amelioration and a return of pine to the
local vegetation, which was probably similar to modern northern
larch forests with dense stone pine and shrub alder understory.
This interpretation is in line with the biome reconstruction (Fig. 3A)
demonstrating the highest affinity scores for the cold deciduous
forest biome. The difference between the maximum score of forest
biomes and the maximum score of open biomes (Fig. 3B) is relatively
large, thus indicating the dominance of arboreal vegetation in
the area. Rather high contents of some coprophilous fungi spores
(Gelasinospora, Sordaria, and Sporormiella) point indirectly to the
presence of herbivores (Baker et al., 2013) in the lake vicinity.
Open tundra and steppe-like herb communities with Artemisia,
(difference between the maximum score among forest biomes and the maximum score among non-forest biomes at each level) calculations see Tarasov et al. (2013). Changes in
dominant biomes (A) are reconstructed using two biome-taxa matrixes discussed in details in Tarasov et al. (2013)/Brigham-Grette et al. (2013) and in Bigelow et al. (2003),
respectively. The abbreviated biome names in Bigelow et al. (2003) are DRYT for graminoid and forb tundra (i.e. dry tundra), SHRU for low- and high-shrub tundra and CLDE for cold
deciduous forest and TAIG for cold evergreen needle-leaved forest (i.e. taiga).
A.A. Andreev et al. / Quaternary Science Reviews xxx (2016) 1e14 9
Please cite this article in press as: Andreev, A.A., et al., Millennial-scale vegetation changes in the north-eastern Russian Arctic during the
Pliocene/Pleistocene transition (2.7e2.5 Ma) inferred from the pollen record of Lake El’gygytgyn, Quaternary Science Reviews (2016), http://
dx.doi.org/10.1016/j.quascirev.2016.03.030
Poaceae, and Cyperaceae dominated in the local vegetation between
ca 2.692 and 2.684 Ma (PZ-III, Fig. 2, central part of MIS G4)
thus pointing to rather dry and cold climate conditions. However,
forested habitats (larch stands mixed with stone pine, shrub alder
and birch) still survived in more protected places like river valleys.
The biome reconstruction also shows that tundra has the highest
affinity scores (Fig. 3A). A rise in the landscape openness (Fig. 3B)
reflects significant strengthening of non-arboreal vegetation in the
area. The relatively high presence of Zygnema cysts and a small
peak of Botryococcus remains in the sediments point to an expansion
of shallow-water environments, likely as a result of lake-level
lowering due to dry climate.
Larch forest with stone pine and shrub alder in the understory
dominated the local vegetation between ca. 2.684 and 2.679 Ma
(PZ-IV, Fig. 2, transition from MIS G4 to MIS G3, Fig. 3G). Climate
amelioration is also indicated by a slight increase in forestation
(Fig. 3B) and the spread of cold deciduous forest biome in the area
(Fig. 3A).
Starting at 2.679 Ma (onset of PZ-IV, Fig. 2, lower part of MIS G3,
Fig. 3G), however, forested habitats quickly disappeared, and
steppe-like coenoses with Artemisia, Poaceae, Cyperaceae, Caryophyllaceae,
Thalictrum, and Selaginella increased again, suggesting
climate deterioration. Consequently, the tundra biome exhibits
the highest affinity scores (Fig. 3A), thus reflecting a significantly
open, treeless landscape (Fig. 3B). The relatively high presence of
Zygnema cysts and small Botryococcus peaks in the sediments
accumulated at the beginning of this interval (low part of PZ-V,
Fig. 2) again pointing to more shallow-water environments.
The geochemical data from the lake sediments also exhibit
changes interpreted as the onset of a pronounced glacial-tointerglacial
cyclicity (for details see Wennrich et al., 2014;
Wennrich et al., in this issue). These changes display an overall
change not only in the lake but also in its catchment that just
slightly postdates a drop in precipitation and winter temperatures
at 2.73 Ma reconstructed from pollen data (Brigham-Grette et al.,
2013; Tarasov et al., 2013). Some climate deterioration is also reflected
in the Lake Baikal pollen record pointing to the expansion of
dry forest types with pine after 2.68 Ma (Demske et al., 2002).
Larch stands appear again in the lake vicinity between 2.672 and
2.665 Ma (PZ-VI of Fig. 2, central part of MIS G3, Fig. 3G), suggesting
climate amelioration. Drastically increased pollen contents of
Betula and Cyperaceae, as well as Sphagnum and Polypodiaceae
spores likely reflect a broader distribution of wetter habitats in the
lake area. Most likely, the vegetation resembles the modern open
larch forests close to the northern limit of larch distribution. Rather
high contents of Gelasinospora and other coprophilous fungi spores
indirectly point to presence of numerous grazing animals around
the lake, and therefore, also indicate a relatively open landscape.
5.4. Environmental conditions ca. 2.665e2.626 Ma
Larch forest with some spruce and numerous shrub pines in the
understory dominated the Lake El’gygytgyn area between 2.665
and 2.655 Ma (PZ-VII and PZ-VIII, Fig. 2, upper part of MID G3,
Fig. 3G). The biome reconstruction (Fig. 3A) shows that cold deciduous
forest and taiga have the highest affinity scores in line with
the qualitative interpretation of pollen data. The landscape openness
significantly decreased (Fig. 3B). All these data suggest that the
climate conditions became much warmer and wetter than before
and that this climate amelioration reflects the climatic optimum of
MIS G3.
Spruce pollen disappear from the spectra between 2.648 and
2.646 Ma (the uppermost part of PZ VII, Fig. 2, transition from MIS
G3 to MIS G2, Fig. 3G), pointing to a successive deterioration of
climate conditions. A very cold and dry climate prevailed at Lake
El’gygytgyn between ca 2.646 and 2.636 Ma (PZ-IX, Fig. 2, middle
part of MIS G2, Fig. 3G), when coniferous taxa (Pinus, Larix) disappeared.
Instead, steppe-like herb communities dominated the
local vegetation during this interval. The biome reconstructions
(Fig. 3A-B) also point to a treeless environment. This period may be
correlated with the onset of the most extensive Cordilleran ice
sheet in north-western Canada, which was dated to 2.64 Ma (Hidy
et al., 2013). This also coincides with evidence for the first ice-rafted
debris in Northern Atlantic marine sediment cores, which originate
from an ice sheet on the North American continent and were dated
at around 2.64 Ma (De Schepper et al., 2014 and references therein).
Birch and alder shrub thickets again became common in the
region between 2.636 and 2.626 Ma (PZ-X, Fig. 2, transition from
MIS G2 to MIS G1, Fig. 3G) thus hinting on warmer and wetter
climate conditions. Rather high percentages of Larix document that
larch has also grown in the vicinity of the lake. The biome reconstruction
(Fig. 3A) is inline with these interpretations, and shows
the highest affinity scores for cold deciduous forest and taiga. The
landscape openness reconstruction also supports these interpretations
andindicates an increased role of trees around the
lake (Fig. 3B). However, a relatively high presence of Artemisia in
the lower part of PZ-X reflects a rather dry climate, still favorable
for the cold steppe habitats.
Cold steppe habitats with Artemisia completely absent from the
pollen assemblages around 2.63 Ma at the onset of MIS G1 (upper
part of PZ-X, Fig. 2) reflect further climate amelioration. The
simultaneously rather high contents of Gelasinospora spores and
other coprophilous fungi reflect the presence of grazing animals
around the lake, which coincides with the existence of steppe
habitats in lake’s vicinity.
5.5. Environmental conditions ca. 2.626e2.595 Ma
According to the pollen spectra pine and larch returned to the
area between 2.626 and 2.617 Ma (PZ-XI, Fig. 2, middle part of MIS
G1, Fig. 3G), when the regional vegetation was dominated by larch
forests with stone pine, shrubby alder, and numerous ericaceous
plants in the understory. Single spruces might also have grown in
more protected places such as river valleys. The biome reconstruction
(Fig. 3A) shows that cold deciduous forest, which has the
highest affinity scores, was the dominant vegetation type. Some
forestation of the landscape is also indicated by the difference between
the maximum score of forest biomes and the maximum
score of open biomes (Fig. 3B). The vegetation changes clearly
reflect that the climate was significantly warmer and wetter than
during the previous interval.
Drier and colder environmental conditions between 2.617 and
2.603 Ma (PZ-XII, Fig. 2, transition from MIS G1 to MIS 104 and
middle MIS 104, Fig. 3G) are suggested by a gradual decrease of
Pinus and especially by the rather high presence of Artemisia, Caryophyllaceae,
Brassicaceae, and other herb and Selaginella spores in
pollen assemblages. Vegetation during this interval was characterized
by larch forests with some stone pine, shrubby alder and
birch in understory, alternating with open steppe- and tundra-like
habitats. The biome reconstructions (Fig. 3A-B) are in good accordance
with this interpretation.
A reduction of forested areas and strong expansion of sage-grass
steppe communities and dry rock-steppe habitats with Selaginella,
which point to dry and cold conditions, are also notable in the
Baikal region after 2.62 Ma (Demske et al., 2002). At about the same
time, around 2.6 Ma, dry climate conditions were established on
the Chinese Loess Plateau as well (Kukla and Cilek, 1996; Ding et al.,
1997 and references therein).
Between 2.603 and 2.595 Ma (PZ-XIII, Fig. 2, upper part of MIS
104, Fig. 3G) steppe-like communities with Artemisia, Poaceae, and
A.A. Andreev et al. / Quaternary Science Reviews xxx (2016) 1e1410
Please cite this article in press as: Andreev, A.A., et al., Millennial-scale vegetation changes in the north-eastern Russian Arctic during the
Pliocene/Pleistocene transition (2.7e2.5 Ma) inferred from the pollen record of Lake El’gygytgyn, Quaternary Science Reviews (2016), http://
dx.doi.org/10.1016/j.quascirev.2016.03.030
Cyperaceae became dominant in the regional vegetation, thus
reflecting further climate deterioration. The biome reconstruction
for this interval shows that tundra has the higher affinity scores and
cold steppe appears as a biome for the first time (Fig. 3A). In parallel
the landscape openness increased (Fig. 3B). The upper boundary of
the interval corresponds well to the transition from MIS 104 to MIS
103 (Fig 3G). A relatively high presence of Zygnema cysts and remains
of Botryococcus colonies point a stronger influence of
shallow-water environments on the sedimentations at site 5011-1,
which may be due to a lowered lake level in consequence of the dry
climate. Nevertheless, high contents of Sphagnum spores indicate
that swampy habitats were common around the lake. Similar to the
present day, Sphagnum mosses might locally have grown in wetter
habitats along small streams that enter the lake.
PZ-XIII widely coincides with the first occurrence of the socalled
facies A in the sediment record of Lake El’gygytgyn (Fig. 2).
This facies reflects sedimentation processes under a perennial ice
cover (Melles et al., 2012; Wennrich et al., 2014; Wennrich et al., in
this issue), whose formation requires mean annual air temperatures
of at least 4 ± 0.5 C lower than today (Nolan, 2013).
5.6. Environmental conditions ca. 2.595e2.558 Ma
Tundra-like coenoses with dwarf birches and sedges became
dominant in the regional vegetation between 2.595 and 2.588 Ma
(PZ-XIV, Fig. 2, lower part of MIS 103, Fig. 3G). That points to a
climate much cooler compared to the previous interval, as also
reflected in the biome reconstructions (Fig. 3A-B). Climate cooling
at the onset of the Pleistocene may also have led to the formation of
permafrost at Lake El’gygytgyn, as indicated by quartz grains in the
lake sediments that suggest enhanced cryogenic weathering in the
catchment since about 2.55 Ma (Schwamborn et al., 2013). Climate
deterioration ca 2.6 Ma ago was also inferred for eastern Beringia,
to the east of the Bering Strait, where pollen and macrofossil records
demonstrate that Pinus and Picea species disappeared or
became greatly reduced in the local vegetation, while grasses and
other herbaceous taxa increased (Schweiger et al., 2011 and references
therein). This cooling may also be associated with the onset
of the so-called Okanaanean Glaciation that occurred in eastern
Chukotka around 2.6 Ma (Laukhin et al., 1999; Laukhin, 2014).
However, the age control of the glacial sediments attributed to the
Okanaanean Glaciation is poor and based only on biostratigraphical
(pollen and diatom) evidence. In the Baikal area, a remarkable
reduction of forested areas took place after 2.61 Ma, while steppe
environments expanded strongly (Demske et al., 2002). Furthermore,
the first episode of rapid loess deposition in Central China
also occurred at ~2.6 Ma, indicating strong intensification of the
Siberian cold-high pressure regime, and accordingly, a profound
cooling of the regional climate (Han et al., 1997). In the marine
realm, sediment records show significant increase of ice-rafted
debris around 2.6 Ma (Jansen et al., 2000), which demonstrates
that global cooling had a strong influence on the intensification of
the northern hemisphere glaciation. This coincides with a southward
shift of North Atlantic Current, as reflected in palynological
data from the North Atlantic (Hennissen et al., 2014.)
Open larch forests with dense shrub alder and birch understory
dominated in the region from 2.588 to 2.579 Ma (PZ-XV, Fig. 2,
middle part of MIS 103, Fig. 3G). Somewhat more favorable climate
conditions, reflecting the MIS 103 optimum, are also suggested by a
slight increase in Pinus pollen, although pine probably did not grow
in the lake vicinity. The biome reconstruction shows that cold deciduous
forest became the dominant vegetation type (Fig. 3A) and
forestation increased (Fig 3B). The transition from a treeless to a
forested environment at Lake El’gygytgyn corresponds with the
Pliocene/Pleistocene and paleomagnetic Gauss/Matuyama
boundaries (Nowaczyk et al., 2013 and references therein).
Between ca. 2.579 and 2.558 Ma (PZ-XVI, Fig. 2, upper MIS 103 to
upper MIS 102, Fig. 3G), larch and especially shrub alder decreased
remarkably in the local vegetation, while open grass-herb-sageSelaginella
dominated habitats became common around the lake.
These changes point to rather dry and cold climate conditions.
Accordingly, tundra has the highest affinity scores (Fig. 3A). A small
increase in the Botryococcus remains and Zygnema cysts again
suggests enhanced influx from shallow-water environments, which
likely were due to the dry climate that resulted in lake-level
lowering.
5.7. Environmental conditions ca. 2.558e2.533 Ma
Larch forest with few shrub pines became more wide-spread
around the lake between ca 2.558 and 2.553 Ma (PZ-XVII, Fig. 2,
upper part of MIS 102, Fig. 3G), thus pointing to a slightly more
favorable (wetter and probably warmer) climate. Wetter local environments
are also suggested by the increased presence of alder
and Sphagnum. The biome reconstruction reveals a strengthening
of the cold deciduous forests (Fig. 3A) and increased forestation of
the landscape (Fig 3B).
Between ca 2.553 and 2.546 Ma (PZ-XVIII, Fig. 2, transition from
MIS 102 to MIS 101, Fig. 3G) the vegetation was dominated by larch
forests with some stone pine, shrubby alder, and birch in understory.
This suggests significant climate amelioration, which is in
good accordance with the biome reconstructions (Fig. 3A-B).
Furthermore, relatively high contents of Gelasinospora and spores
of some other coprophilous fungi, indirectly point to the presence
of grazing animals around the lake during this period.
In the interval from ca. 2.546 to 2.532 Ma (PZ-XIX, Fig. 2, transition
from MIS 101 to MIS 100, Fig. 3G) the understory (stone pine,
shrubby alder, dwarf birch) of the larch forests became denser. Club
mosses also increased in the local vegetation. The vegetation
changes suggest that climate conditions remained rather warm and
wet, as supported also by the biome reconstruction which shows
that forest biomes (i.e. cold deciduous forest and taiga) have the
highest affinity scores (Fig. 3A) and the landscape openness
significantly decreased at that time (Fig. 3B).
5.8. Environmental conditions ca. 2.533e2.465 Ma
In the interval ca 2.533 and 2.515 Ma (PZ-XX, Fig. 2, middle part
of MIS 100, Fig. 3G), Coniferous trees and shrubs completely disappeared
in the region, while open, steppe-and meadow-like
habitats with Artemisia, Thalictrum, Poaceae and Caryophyllaceae
became broadly distributed. In the biome reconstruction tundra
and cold steppe have the highest affinity scores (Fig. 3A), and the
landscape openness also increased drastically (Fig. 3B). Numerous
Botryococcus remains, especially at the beginning of the PZ, reflect
abundant shallow-water habitats, likely due to lake lowering. The
revealed changes clearly point to particularly dry and cold climate
conditions at Lake El’gygytgyn during MIS 100. During this glacial,
the closure of the Panamanian Gateway commenced, and sea level
dropped by 60e90 m as a result of increased ice volume
(Groeneveld et al., 2014 and references therein). Bailey et al. (2012)
deduced from marine records from the North Atlantic Ocean that
this earliest large-amplitude Pleistocene glacial, ~2.52 Ma, was
arguably a key glacial characterized by abundant iceberg calving
from large ice-sheets on multiple continents in the high northern
latitudes.
Subsequently, between 2.515 and 2.510 Ma (PZ-XXI, Fig. 2; MIS
100 to MIS 99 transition, Fig. 3G), tundra and landscape openness
kept highest affinity scores and high values, respectively, (Fig. 3A
and B). However, dwarf birch coenoses became more common,
A.A. Andreev et al. / Quaternary Science Reviews xxx (2016) 1e14 11
Please cite this article in press as: Andreev, A.A., et al., Millennial-scale vegetation changes in the north-eastern Russian Arctic during the
Pliocene/Pleistocene transition (2.7e2.5 Ma) inferred from the pollen record of Lake El’gygytgyn, Quaternary Science Reviews (2016), http://
dx.doi.org/10.1016/j.quascirev.2016.03.030
while steppe-like communities with Artemisia started to decline
from the vegetation, thus suggesting some climate amelioration. An
increase of Sphagnum may point to wetter soil conditions.
Between 2.515 and 2.492 Ma (PZ-XXII, Fig. 2, middle MIS 99,
Fig. 3C) open larch forest with numerous dwarf birches and some
shrub alders in understory dominated the area. Together with a
distinct reduction in landscape openness (Fig. 3B) this suggests
further climate amelioration. Increased presence of Sphagnum may
be traced back to a paludification and wetter soil conditions during
this interval. A shift to relatively favorable environmental conditions
at about 2.5 Ma ago was also reconstructed from the
contemporaneous Baikal pollen record which suggest the growth of
moisture-dependent fir and even broadleaved taxa in the area
(Demske et al., 2002).
5.9. Climate-vegetation lag and climate trends crossing the
Pliocene/Pleistocene boundary
Both the qualitative pollen-based (Fig. 2) and the biome (Fig. 3AB)
reconstructions reveal some lags between global climate change,
highlighted by the benthic oxygen isotope stack (Fig. 3G), and the
vegetation responses in the study area. As sedimentary proxies
from Lake El’gygytgyn argue against significant redeposition of
older material (i.e. contamination of the pollen-poor glacial sediment
by pollen reworked from the previous interglacial, Wennrich
et al., in this issue), the observed lags suggest a delay in the
response of the regional vegetation to climate change, at least
during the transition from the warmest interglacials (i.e. MIS G3
and 103) to glacials (i.e. MIS G2 and 100). An alternative explanation
is a possible millennial-scale uncertainty of the age-depth
model (Melles et al., 2012), which is based on magnetostratigraphy
and tuning of proxy data to the regional insolation and
global marine isotope stratigraphy (Fig. 3G). Bearing in mind that
not every MIS transition shows delayed response in vegetation, this
possibility must be considered. Checking both hypotheses is a task
of forthcoming research.
It is interesting to note that the biome reconstruction does not
show pronounced differences between the climate cycles presented
here prior to and after the Pliocene/Pleistocene boundary
(Fig. 3), except distinctly drier and colder vegetation and environments
suggested for MIS 100 by the biome (Fig. 3A), landscape
openness (Fig. 3B), pollen productivity (Fig. 3D), and marine oxygen
isotope record (Fig. 3G). The Pliocene/Pleistocene boundary at
2.588 Ma shows neither a gradual nor a step-wise shift towards a
colder and drier climate. This finding is in agreement with results
presented by Brigham-Grette et al. (2013) based upon a preliminary,
coarser-resolution pollen record from Lake El’gygytgyn
that was combined with sedimentary proxies. These data suggested
that the major change in regional vegetation and climate at Lake
El’gygytgyn occurred earlier, between 2.71 and 2.69 Ma, simultaneous
with the onsets of North Pacific stratification (Haug et al.,
2005) and Northern Hemispheric glaciation (Brierley et al., 2009).
On the other hand, warmer than present Arctic summers existed
until ~2.2 Ma ago (Tarasov et al., 2013), indicating that Arctic
cooling was insufficient to support large-scale ice sheets until the
early Pleistocene (Brigham-Grette et al., 2013).
6. Conclusions
Our results demonstrate that the late Pliocene/early Pleistocene
pollen record of Lake El’gygytgyn is an excellent archive of vegetation
and climate changes in the northeastern Russian Arctic. The
quantitative biome reconstructions are in a good accordance with
the qualitative interpretation of pollen spectra. The two approaches
employed for pollen-based biome reconstructions reveal the same
set of the dominant biomes.
Generally, the record reflects the main paleoenvironmental
fluctuations in the region. During the studied time interval the
most pronounced environmental changes (appearance of tundraand
steppe-like habitats) pointing to cold and dry conditions,
occurred around 2.710, 2.645, 2.600, and 2.532 Ma.
Open steppe-like, tundra and shrub tundra vegetation dominated
during the early Pleistocene, however, relatively warm intervals
with larch forest and stone pine growing around the lake
occurred ca 2.587e2.578, 2.558e2.532, and 2.551e2.550 Ma ago.
Strong peaks in green algae remains (mostly Botryococcus colonies)
around 2.695, 2.678, 2.602e2.595, and 2.535e2.515 Ma reflect
increased shallow-water conditions coinciding with dry climate
intervals reconstructed by pollen indicators.
The biome and qualitative pollen-based reconstructions reveal
some lags between the global climate change and regional vegetation
responses, however testing of this hypothesis is the task of
forthcoming research, which will incorporate all the El’gygytgyn
pollen data, including that from the Pleistocene. The same holds
true for more detailed investigations of the periodicity of vegetation
changes at Lake El’gygytgyn throughout the Late Pliocene and
Pleistocene.
Acknowledgements
We like to thank all participants on the drilling campaign at Lake
El’gygytgyn in spring 2009 for collecting the IDCP drill cores. C.
Kramer is acknowledged for their competent help in the preparation
of pollen samples. The work of A.A. Andreev was sponsored by
the German Research Foundation (DFG grant ME 1169/24), the
German Federal Ministry of Education and Research (BMBF, grant
03G0839A), and partly via the Russian Government Program of
Competitive Growth of Kazan Federal University. The contribution
of P.E. Tarasov to this study is funded via the DFG Heisenberg
Program (TA 540/5).
References
Andreev, A.A., Morozova, E., Fedorov, G., Schirrmeister, L., Bobrov, A.A., Kienast, F.,
Schwamborn, G., 2012. Vegetation history of central Chukotka deduced from
permafrost paleoenvironmental records of the El’gygytgyn Impact Crater. Clim.
Past 8, 1287e1300.
Andreev, A.A., Tarasov, P.E., Wennrich, V., Raschke, E., Herzschuh, U.,
Nowaczyk, N.R., Brigham-Grette, J., Melles, M., 2014. Late Pliocene and Early
Pleistocene environments of the north-eastern Russian Arctic inferred from the
Lake El’gygytgyn pollen record. Clim. Past 10, 1e23.
Baker, A.G., Bhagwar, S., Willis, K.J., 2013. Do dung fungal spores make a good proxy
for past distribution of large herbivores? Quat. Sci. Rev. 62, 21e31.
Bailey, I., Liu, Q., Swann, G.E.A., Jiang, Z., Sun, Y., Zhao, X., Roberts, A.P., 2011. Iron
fertilisation and biogeochemical cycles in the sub-Arctic northwest Pacific
during the late Pliocene intensification of northern hemisphere glaciation.
Earth Planet. Sci. Lett. 307, 253e265.
Bailey, I., Foster, G.L., Wilson, P.A., Jovane, L., Storey, C.D., Trueman, C.N., Becker, J.,
2012. Flux and provenance of ice-rafted debris in the earliest Pleistocene subpolar
North Atlantic Ocean comparable to the last glacial maximum. Earth
Planet. Sci. Lett. 341e344, 222e233.
Belikovich, A.V., Galanin, A.V., 1994. El’gygytgyn Lake reservation (central Chukotka).
Vestn. FEB RAS 4, 22e24 (in Russian).
Berglund, B.E., Ralska-Jasiewiczowa, M., 1986. Pollen analysis and pollen diagrams.
In: Berglund, B.E. (Ed.), Handbook of Holocene Palaeoecology and Palaeohydrology.
Wiley, Chichester, pp. 455e484.
Bigelow, N.H., Brubaker, L.B., Edwards, M.E., Harrison, S.P., Prentice, I.C.,
Anderson, P.M., Andreev, A.A., Bartlein, P.J., Christensen, T.R., Cramer, W.,
Kaplan, J.O., Lozhkin, A.V., Matveyeva, N.V., Murray, D.F., McGuire, A.D.,
Razzhivin, V.Y., Ritchie, J.C., Smith, B., Walker, D.A., Gajewski, K., Wolf, V.,
Holmqvist, B.H., Igarashi, Y., Kremenetskii, K., Paus, A., Pisaric, M.F.J.,
Volkova, V.S., 2003. Climate change and Arctic ecosystems: 1. Vegetation
changes north of 55 N between the last glacial maximum, mid-Holocene, and
present. J. Geophys. Res. 108 (D19), 8170.
Bobrov, A.E., Kupriyanova, L.A., Litvintseva, M.V., Tarasevich, V.F., 1983. Spores and
Pollen of Gymnosperms from the Flora of the European Part of the USSR. Nauka,
Leningrad (in Russian).
Brierley, C.M., Fedorov, A.V., Liu, Z., Herbert, T.D., Lawrence, K.T., LaRiviere, J.P., 2009.
A.A. Andreev et al. / Quaternary Science Reviews xxx (2016) 1e1412
Please cite this article in press as: Andreev, A.A., et al., Millennial-scale vegetation changes in the north-eastern Russian Arctic during the
Pliocene/Pleistocene transition (2.7e2.5 Ma) inferred from the pollen record of Lake El’gygytgyn, Quaternary Science Reviews (2016), http://
dx.doi.org/10.1016/j.quascirev.2016.03.030
Greatly Expanded Tropical Warm Pool and Weakened Hadley Circulation in the
Early Pliocene Science, vol. 323, pp. 1714e1718.
Brigham-Grette, J., Melles, M., Minyuk, P., Andreev, A., Tarasov, P., DeConto, R.,
Koenig, S., Nowaczyk, N., Wennrich, V., Rosen, P., Haltia-Hovi, E., Cook, T.,
Gebhardt, C., Meyer-Jacob, C., Snyder, J., Herzschuh, U., 2013. Pliocene warmth,
extreme polar amplification, and stepped pleistocene cooling recorded in NE
Russia. Science 340, 1421e1427.
De Schepper, S., Gibbard, P.L., Salzmann, U., Ehlers, J., 2014. A global synthesis of the
marine and terrestrial evidence for glaciation during the Pliocene Epoch. Earth
Sci. Rev. 135, 83e102.
Demske, D., Mohr, B., Oberh€ansli, H., 2002. Late Pliocene vegetation and climate of
the Lake Baikal region, southern East Siberia, reconstructed from palynological
data. Palaeogeogeogr. Palaeoclimatol. Palaeoecol. 184, 107e129.
Ding, Y., Rutter, N.W., Liu, T., 1997. The onset of extensive loess deposition around
the G/M boundary in China and its paleomagnetic implications. Quat. Int. 40,
53e60.
Duk-Rodkin, A., Barendregt, R.W., White, J.M., 2010. An extensive late Cenozoic
terrestrial record of multiple glaciations preserved in the Tintina Trench of
west-central Yukon: stratigraphy, paleomagnetism, paleosols, and pollen. Can. J.
Earth Sci. 47, 1003e1028.
Edwards, M.E., Anderson, P.M., Brubaker, L.B., Ager, T.A., Andreev, A.A., Bigelow, N.H.,
Cwynar, L.C., Eisner, W.R., Harrison, S.P., Hu, F.S., Jolly, D., Lozhkin, A.V.,
MacDonald, G.M., Mock, C.J., Ritchie, J.C., Sher, A.V., Spear, R.W., Williams, J.W.,
Yu, G., 2000. Pollen- based biomes for Beringia 18,000, 6000 and 0 14
C yr BP.
J. Biogeogr. 27, 521e554.
Grimm, E.C., 2004. TGView. Illinois State Museum. Research and Collections Center,
Springfield.
Groeneveld, J., Hathorne, E.C., Steinke, S., DeBey, H., Mackensen, A., Tiedemann, R.,
2014. Glacial induced closure of the Panamanian Gateway during marine
isotope stages (MIS) 95e100 (~2.5 Ma). Earth Planet. Sci. Lett. 404, 296e306.
Guiot, J., Goeury, C., 1996. PPPBASE, a software for statistical analysis of palaeoecological
and palaeoclimatological data. Dendrochronologia 14, 295e300.
Haltia, E.M., Nowaczyk, N.R., 2014. Magnetostratigraphy of sediments from Lake
El’gygytgyn ICDP site 5011-1: paleomagnetic age constraints for the longest
continental record from the Arctic. Clim. Past 10, 623e642.
Han, J., Fyfe, W.S., Longstaffe, F.J., Palmer, H.C., Yan, F.H., Mai, X.C., 1997. Pliocene/
Pleistocene climatic change recorded in fluviolacustrine sediments in Central
China. Palaeogeography, Palaeoclimatology. Palaeoecology 135, 27e39.
Haug, G., Ganopolski, A., Sigman, D.M., Rosell-Mele, A., Swann, G.E.A.,
Tiedemann, R., Jaccard, S.L., Bollmann, J., Maslin, M.A., Leng, M.J., Eglinton, G.,
2005. North 728 Pacific seasonality and the glaciation of North America 2.7
million years ago. Nature 729, 821e825.
Hennissen, J.A.I., Head, M.J., De Schepper, S., Groeneveld, J., 2014. Palynological
evidence for a southward shift of the North Atlantic current at ~2.6 Ma during
the intensification of late Cenozoic Northern Hemisphere glaciations. Paleoceanography
29, 564e580.
Hidy, A.J., Gosse, J.C., Froese, D.G., Bond, J.D., Rood, D.H., 2013. A latest Pliocene age
for the earliest most extensive Cordilleran Ice Sheet in northwestern Canada.
Quat. Sci. Rev. 61, 77e84.
IPCC, 2007. In: Pachauri, R.K. (Ed.), Fourth Assessment Report: Climate Change: the
AR4 Synthesis Report. IPCC, Geneva, Switzerland.
Jansen, E., Fronval, T., Rack, F., Channell, J.E.T., 2000. Pliocene-Pleistocene ice rafting
history and cyclicity in the Nordic Seas during the last 3.5 Ma. Paleoceonography
15, 706e721.
Kaplan, J.O., 2001. Geophysical Applications of Vegetation Modeling. Doctoral
dissertation. Lund Univ., Lund, Sweden.
Kleiven, H., Jansen, E., Fronval, T., Smith, T.B., 2002. Intensification of Northern
Hemisphere glaciations in the circum Arctic region (3.5-2.4 Ma) e ice-rafted
detritus evidence. Palaeogeogr. Palaeoclimatol. Palaeoecol. 184, 213e223.
Kozhevnikov, Yu.P., 1993. Vascular plants around El’gygytgyn Lake. In: Natural
Depression El’gygytgyn Lake (Problems of Study and Preservation). NEISRI FEB
RAS, Magadan, pp. 62e82 (in Russian).
Kukla, G., Cilek, V., 1996. Plio-Pleistocene megacycles: record of climate and tectonics.
Palaeogeogr. Palaeoclimatol. Palaeoecol. 120, 171e194.
Kupriyanova, L.A., Alyoshina, L.A., 1978. Pollen and Spores of Plants from the Flora of
European Part of USSR, vol. II. Academy of Sciences USSR, Komarov Botanical
Institute, Leningrad (in Russian).
Laukhin, S.A., Klimanov, V.A., Belaya, B.V., 1999. Late Pliocene and Pleistocene
paleoclimates in Northeastern Chukotka. Sb. Geol. Ved. e Antropozoikum 23,
17e24.
Laukhin, S.A., 2014. About the age of the oldest glaciations on Chukotka. In: Proceedings
of VIII University’s Geological Readings“ Geology and Mineral Sources
of Quaternary Deposits”, 3-4 April, 2014, Minsk, Belarus, Belarusian State University,
Minsk, Belarus. http://elib.bsu.by/handle/123456789/94642.
Layer, P., 2000. Argon-40/argon-39 age of the El’gygytgyn impact event, Chukotka,
Russia. Meteorit. Planet. Sci. 35, 591e599.
Lisiecki, L.E., Raymo, M.E., 2005. A PlioceneePleistocene stack of 57 globally
distributed benthic d18
O records. Paleoceanography 20 (1), PA1003. http://
dx.doi.org/10.1029/2004PA001071.
Lozhkin, A.V., Anderson, P.M., 2013. Vegetation responses to interglacial warming in
the Arctic: examples from Lake El’gygytgyn, Far East Russian Arctic. Clim. Past 9,
1211e1219.
Lozhkin, A., Anderson, P., Vartanyan, S., Brown, T., Belaya, B., Kotov, A., 2001. Reconstructions
of late Quaternary paleoenvironments and modern pollen data
from Wrangel Island (northern Chukotka). Quat. Sci. Rev. 20, 217e233.
Matrosova, T.V., Anderson, P.M., Lozhkin, A.V., Minyuk, P.S., 2004. Climate history of
Chukotka during the last 300,000 years from the Lake El’gygytgyn pollen record.
In: Lozhkin, A.V. (Ed.), Climate Records from Quaternary Sediments of
Beringia. NEISRI FEB RAS, Magadan, pp. 26e42 (in Russian).
Matrosova, T.V., 2006. Modern spore-pollen spectra of Anadyr Plateau (El’gygytgyn
Lake). In: Chereshnev, I.A. (Ed.), Geology, Geography and Biodiversity of NorthEast
Russia. Materials of Far-east Regional Conference in Memory of A.P. Vas’kovskiy.
NEISRI FEB RAS, Magadan, pp. 159e162 (in Russian).
Matrosova, T.V., 2009. Vegetation and Climate Change in Northern Chukotka during
the Last 350 ka (Basing on Lacustrine Pollen Records from El’gygytgyn Lake.
Vestnik FEB RAS 2, 23-30 (in Russian).
Matthiessen, J., Knies, J., Vogt, C., Stein, R., 2009. Pliocene palaeoceanography of the
Arctic Ocean and subarctic seas. Philos. Trans. R. Soc. Lond. A 367, 21e48.
Melles, M., Brigham-Grette, J., Minyuk, P., Koeberl, C., Andreev, A., Cook, T.,
Gebhardt, C., Haltia-Hovi, E., Kukkonen, M., Nowaczyk, N., Schwamborn, G.,
Wennrich, V., El’gygytgyn Scientific Party, 2011. The Lake El’gygytgyn scientific
drilling project e conquering arctic challenges in continental drilling. Sci. Drill.
11, 29e40.
Melles, M., Brigham-Grette, J., Minyuk, P.S., Nowaczyk, N.R., Wennrich, V.,
DeConto, R.M., Anderson, P.M., Andreev, A., Coletti, A., Cook, T., Haltia-Hovi, E.,
Kukkonen Lozhkin, A.V., Rosen, P., Tarasov, P., Vogel, H., Wagner, B., 2012. 2.8
million years of Arctic climate change from Lake El’gygytgyn, NE Russia. Science
337, 315e320.
Mokhova, L., Tarasov, P., Bazarova, V., Klimin, M., 2009. Quantitative biome reconstruction
using modern and late Quaternary pollen data from the southern part
of the Russian Far East. Quat. Sci. Rev. 28, 2913e2926.
Müller, S., Tarasov, P.E., Andreev, A.A., Tütken, T., Gartz, S., Diekmann, B., 2010. Late
Quaternary vegetation and environments in the Verkhoyansk Mountains region
(NE Asia) reconstructed from a 50-kyr fossil pollen record from Lake Billyakh.
Quat. Sci. Rev. 29, 2071e2086.
Naafs, B.D.A., Hefter, J., Acton, G., Haug, G.H., Martínez-Garcia, A., Pancost, R.,
Stein, R., 2012. Strengthening of North American dust sources during the late
Pliocene (2.7 Ma). Earth Planet. Sci. Lett. 317e318, 8e19.
Nisbet, E.G., Dlugokencky, E.J., Bousquet, P., 2014. Methane on the rise e again.
Science 343, 493e495.
Nolan, M., Brigham-Grette, J., 2007. Basic hydrology, limnology, and meteorology of
modern El’gygytgyn Lake, Siberia. J. Paleolimnol. 37, 17e35.
Nolan, M., 2013. Quantitative and qualitative constraints on hind-casting the formation
of multiyear lake-ice covers at Lake El’gygytgyn. Clim. Past 9,
1253e1269.
Nowaczyk, N.R., Haltia, E.M., Ulbricht, D., Wennrich, V., Sauerbrey, M.A., Rosen, P.,
Vogel, H., Francke, A., Meyer-Jacob, C., Andreev, A.A., Lozhkin, A.V., 2013.
Chronology of Lake El’gygytgyn sediments e a combined magnetostratigraphic,
palaeoclimatic and orbital tuning study based on multi-parameter analyses.
Clim. Past 9, 2413e2432. http://dx.doi.org/10.5194/cp-9-2413-2013.
Prentice, I.C., Cramer, W., Harrison, S.P., Leemans, R., Monserud, R.A., Solomon, A.M.,
1992. A global biome model based on plant physiology and dominance, soil
properties and climate. J. Biogeogr. 19, 117e134.
Prentice, I.C., Guiot, J., Huntley, B., Jolly, D., Cheddadi, R., 1996. Reconstructing biomes
from palaeoecological data: a general method and its application to European
pollen data at 0 and 6 ka. Clim. Dyn. 12, 185e194.
Reille, M., 1992. Pollen et spores d’Europe et d’Afrique du nord. Laboratoire de
Botanique Historique et Palynologie, Marseille.
Reille, M., 1995. Pollen et spores d’Europe et d’Afrique du nord. Supplement 1.
Laboratoire de Botanique Historique et Palynologie, Marseille.
Reille, M., 1998. Pollen et spores d’Europe et d’Afrique du nord. Supplement 2.
Laboratoire de Botanique Historique et Palynologie, Marseille.
Schuur, E.A.G., Vogel, J.G., Crummer, K.G., Lee, H., Sickman, J.O., Osterkamp, T.E.,
2009. The effect of permafrost thaw on old carbon release and net carbon exchange
from tundra. Nature 459, 556e559.
Schwamborn, G., Fedorov, G., Schirrmeister, L., Meyer, H., Hubberten, H.-W., 2008.
Periglacial sediment variations controlled by late Quaternary climate and lake
level change at El’gygytgyn Crater, Arctic Siberia. Boreas 37, 55e65.
Schwamborn, G., Schirrmeister, L., Diekmann, B., 2013. Onset of intense permafrost
conditions in Northern Eurasia at ~2.55 Ma seen in a cryogenic weathering
record from Lake El’gygytgyn. Clim. Past Discuss. 9, 6255e6285.
Schweiger, A., Lindsay, R., Zhang, J., Steele, M., and Stern, H., Uncertainty in modeled
arctic sea ice volume, J. Geophys. Res. 116, C00D06.
Stockmarr, J., 1971. Tablets with spores used in absolute pollen analysis. Pollen
Spores 13, 614e621.
Studer, A.S., Martynes-Garsia, A., Jaccard, S.L., Girault, F.E., Sigman, D.M., Haug, G.H.,
2012. Enhanced stratification and seasonality in the Subarctic Pacific upon
Northern Hemisphere Glaciation e new evidence from diatom-bound nitrogen
isotopes, alkenones and archael tetraethers. Earth Planet. Sci. Lett. 351e352,
84e94.
Sundqvist, H.S., Zhang, Q., Moberg, A., Holmgren, K., Kornich, H., Nilsson, J.,
Brattstrom, G., 2010. Climate change between the mid and late Holocene in
northern high latitudes e Part 1: survey of temperature and precipitation proxy
data. Clim. Past 6, 591e608.
Tarasov, P.E., Webb III, T., Andreev, A.A., Afanas’eva, N.B., Berezina, N.A.,
Bezusko, L.G., Blyakharchuk, T.A., Bolikhovskaya, N.S., Cheddadi, R.,
Chernavskaya, M.M., Chernova, G.M., Dorofeyuk, N.I., Dirksen, V.G., Elina, G.A.,
Filimonova, L.V., Glebov, F.Z., Guiot, J., Gunova, V.S., Harrison, S.P., Jolly, D.,
Khomutova, V.I., Kvavadze, E.V., Osipova, I.M., Panova, N.K., Prentice, I.C.,
Saarse, L., Sevastyanov, D.V., Volkova, V.S., Zernitskaya, V.P., 1998. Present-day
A.A. Andreev et al. / Quaternary Science Reviews xxx (2016) 1e14 13
Please cite this article in press as: Andreev, A.A., et al., Millennial-scale vegetation changes in the north-eastern Russian Arctic during the
Pliocene/Pleistocene transition (2.7e2.5 Ma) inferred from the pollen record of Lake El’gygytgyn, Quaternary Science Reviews (2016), http://
dx.doi.org/10.1016/j.quascirev.2016.03.030
and mid-Holocene biomes reconstructed from pollen and plant macrofossil
data from the former Soviet Union and Mongolia. J. Biogeogr. 25, 1029e1053.
Tarasov, P.E., Volkova, V.S., Webb III, T., Guiot, J., Andreev, A.A., Bezusko, L.G.,
Bezusko, T.V., Bykova, G.V., Dorofeyuk, N.I., Kvavadze, E.V., Osipova, I.M.,
Panova, N.K., Sevastyanov, D.V., 2000. Last glacial maximum biomes reconstructed
from pollen and plant macrofossil data from Northern Eurasia.
J. Biogeogr. 27, 609e620.
Tarasov, P., Granoszewski, W., Bezrukova, E., Brewer, S., Nita, M., Abzaeva, A.,
Oberhansli, H., 2005. Quantitative reconstruction of the last interglacial vegetation
and climate based on the pollen record from Lake Baikal, Russia. Clim.
Dyn. 25, 625e637.
Tarasov, P.E., Andreev, A.A., Anderson, P.M., Lozhkin, A.V., Haltia-Hovi, E.,
Nowaczyk, N.R., Wennrich, V., Brigham-Grette, J., Melles, M., 2013. A pollenbased
biome reconstruction over the last 3.562 million years in the Far East
Russian Arctic e new insights climate-vegetation relationships at the regional
scale. Clim. Past 9, 2759e2775.
van Geel, B., 2001. Non-pollen palynomorphs. In: Smol, J.P., Birks, H.J.B., Last, W.M.,
Bradley, R.S., Alverson, K. (Eds.), Tracking Environmental Change Using Lake
Sediments, Terrestrial, Algal and Silicaceous Indicators, vol. 3. Kluwer, Dordrecht,
pp. 99e119.
Wennrich, V., Minyuk, P.S., Borkhodoev, V., Francke, A., Ritter, B., Nowaczyk, N.R.,
Sauerbrey, M.A., Brigham-Grette, J., Melles, M., 2014. Pliocene to Pleistocene
climate and environmental history of Lake El’gygytgyn, Far East Russian Arctic,
based on high-resolution inorganic geochemistry data. Clim. Past 10,
1381e1399.
Wennrich, V., Andreev, A.A., Tarasov, P.E., Fedorov, G., Zhao, W.W., Gebhardt, C.A.,
Meyer-Jacob, C., Snyder, J.A., Nowaczyk, N.R., Chapligin, B., Anderson, P.M.,
Lozhkin, A.V., Minyuk, P.S., Koeberl, C.H., Melles, M., 2016. 3.6 Ma climate and
environmental variability in the terrestrial Arctic as inferred from the unique
sediment record of Lake El’gygytgyn, Far East Russia e a review. Quat. Sci. Rev.
(in this issue).
A.A. Andreev et al. / Quaternary Science Reviews xxx (2016) 1e1414
Please cite this article in press as: Andreev, A.A., et al., Millennial-scale vegetation changes in the north-eastern Russian Arctic during the
Pliocene/Pleistocene transition (2.7e2.5 Ma) inferred from the pollen record of Lake El’gygytgyn, Quaternary Science Reviews (2016), http://
dx.doi.org/10.1016/j.quascirev.2016.03.030