Palaeoenvironmental records from Siberia and the Russian Far East – contributions from DIMA Network members – Introduction

Abstract

As concern about the effects of climate change on northern regions increases, an important goal of palaeoenvironmental science is placing events that appear to be unprecedented – such as the severe boreal forest firesof recent years (Witze 2020)– intoa long-term context. The boreal forest zone covers a large span of latitude from the permafrost-affected northern tree line to the southern borderwith steppe and the diversemixed temperate forest. Over two thirds of the world’s boreal forest and about a third of the Northern Hemisphere terrestrial carbon pool lies within Russian territory, and muchof this is east of theUralMountains, in Siberia and the Russian Far East (SRFE) (Kuusela 1992; Stolbovoi 2002). With the awareness of the region’s sensitivity to climatechangegrowing, it is clear that this vast expanse is understudied. Scientific centres, now associatedwith the Russian Academy of Sciences, have long histories of pioneeringresearch inSRFEandtherecontinues tobean impressive flow of new data from these institutions, despite complex logistics of working in remote locations. A problem, however, is that a large proportion of this research is not available to the international community, primarilybecauseof language limitations (i.e. theneed to publish in English for the international audience and the inability of most of that audience to read papers published in high quality Russian scientific journals). International research cooperation can provide an avenue for greater dissemination of Russian research (for example, the Lake Baikal and Lake El’gygytgyn drilling projects, ICDP 2020a, b), but many other nationally funded projects fall outside these joint ventures. This special section of Boreas contains nine papers, six of which are based entirely on recent Russian research projects and three of which represent international collaborations. It is the first major product of a UK– Russia collaboration of palaeoenvironmental research groups, initiated in 2018, theDIMAnetwork (Developing Innovative Multi-proxy Analyses, see https://research.nc l.ac.uk/dima/ and van Hardenbroek et al. (in press)). The maingoal is to jointlydevelopandconduct researchon the late-Quaternary evolution of climate and ecosystems across SRFE. The papers brought together here illustrate the range of geographical locations under investigation (Fig. 1) and the scope of the disciplinary approaches currently being used in Russia. Field locations range from Kamchatka in the northeast tomountains that border the central Asian steppe in the southwest, and techniques include marine micropalaeontology, palaeomagnetism, and a range of terrestrial proxies, including pollen, plant macrofossils, diatoms, and testate amoebae. Several features unite these investigations. Typically, they represent the first study of its kind, or the first of any kind, in a critical geographical area, and nearly all the sites fall within the influence of the hugely important southeast AsianMonsoon system,which has hadamajor impact on both climate means and variability. Additionally, two studies include regional calibration sets for biological proxies; such data sets are critical given the vast geographical scale of SRFE. Along with the palaeo-studies morework isnecessary toprovidea solidunderstandingof the complex temporal and spatial relationships between the atmosphere, biosphere and cryosphere. In southwest Siberia, Blyakharchuk & Kurina (2021, this issue) use a regionally derived calibration for testate amoebae to trace Late-Holocene, high-frequency moisture fluctuations recorded in sediments of a mire system in the Western Sayan Mountains; these mirror changes that affected the steppe region and influenced human population dynamics in the last two millennia. Bezrukova et al. (2021, this issue) present a high-elevation lacustrine record from the Eastern Sayan Mountains that records the Younger Dryas interval and Holocene mountain vegetation responses to changes in moisture, driven bymonsoon dynamics. The mountains form part of the central Asian ‘water tower’ that is a key source of water for the populous regions of SE Asia. Mikhailova et al. (2021, this issue) provide a 9000-year palaeohydrological study of mire development in the forest-steppe of the Yenisei River basin and place this in a wider geographical context. Their results indicate remarkable similarity across southern Siberia,Mongolia and northern China, with a wet Holocene Thermal Maximum followed by a drier mid-Holocene. Since c. 5000 cal. a BP, however, this southerly taiga region, as well as the Altai-Sayan Mountains experienced, wetter conditions related to increased moisture transport from the North Atlantic by the westerly jets. The other five investigations focus on the Russian Far East. Evstigneeva et al. (2021, this issue) present the first record of diatoms and pollen from the northwest Japan Sea, which records changes in currents and sea