Decadal high-resolution multi-proxy analysis to reconstruct natural and human-induced environmental changes over the last 1350 cal. yr BP in the Altai Tavan Bogd National Park, western Mongolia

Abstract

The ‘Altai Tavan Bogd’ National Park in the north-western part of the Mongolian Altai, Central Asia, is located in a forest-steppe ecosystem. It occurs under the influence of extreme continental and montane climate and is sensitive to natural and anthropogenic impacts. High-resolution (<20 years per sample) multi-proxy data of pollen, non-pollen palynomorphs (NPPs), macro-charcoal, diatoms, and XRF scanning from radiocarbon-dated lacustrine sediments reveal various environmental changes and the impact of different settlement periods for the late-Holocene. From 1350 to 820 cal. yr BP (AD 600–1130), the distribution of grass steppe indicates a climate similar to present-day conditions. Rapid improvements of climatic conditions (e.g. increased rainfall events) possibly favored a recovery of forest-steppe encouraging nomadic movements into alpine areas. In the period from 820 to 400 cal. yr BP (AD 1130–1550), the decline of forested areas suggests an increasingly drier and possibly colder climate. Some political shifts during the Mongol Empire (744–582 cal. yr BP; AD 1206–1368) favored variations in nomadic grazing habits. After 400 cal. yr BP (AD 1550), moisture and temperature increased slightly, and from ca. 40 cal. yr BP (AD 1910) to present, annual temperature continued to increase more markedly favoring an additional water availability due to permafrost degradation. Diatom data suggest several intervals of increased water availability in all periods which might have caused erosion due to heavier rainfall events or increased snow melt. Immediately after most of these high-water intervals, NPP data reveal periods of increased grazing activities in the area.

The link between climate change and biodiversity of lacustrine inhabitants and terrestrial plant communities of the Uvs Nuur Basin (Mongolia) during the last three millennia

“…Even though many climatic reconstructions of the Holocene in Mongolia and Central Asia have been published (Felauer et al, 2012;Feng et al, 2013;Gunin et al, 1999;Peck et al, 2002;Rudaya et al, 2009;Sun et al, 2013;Tian et al, 2014;Unkelbach et al, 2017Unkelbach et al, , 2019Unkelbach et al, , 2020, there is no uniform picture of the climate history and vegetation successions in the region. This was demonstrated in the recent excellent review by Klinge and Sauer (2019).…”

The reconstruction of Holocene northwestern Mongolian fire history based on high-resolution multi-site macro-charcoal analyses

“…For this study, we used eight sediment cores; five were sampled in Altai Tavan Bogd NP (A) in 2014 (Unkelbach et al, 2018;Unkelbach et al, 2021a) and 2016 (Unkelbach et al, 2019;Unkelbach et al, 2020), and three profiles were sampled in Tarvagatai Nuruu NP (B) in 2018 (Unkelbach et al, 2021b;this study). Profile locations and environmental information are given in Table 1 and Figure 2.…”

“…Thus, smaller strictly local fires for producing heat and food for the nomadic herders, in combination with the local topography and vegetation, might have resulted in the individual fire histories after 1,100 cal yr BP. Over the last 100 years, climate warming, degradation of permafrost, changes in herding practices, and industrialization might have all affected the fire regimes (Fernández-Giménez, 1999;Lkhagvadorj et al, 2013;Unkelbach et al, 2020).…”

“…In recent years, the fire history of Mongolia and its adjacent regions has only been discussed sparsely. In the Mongolian Altai, several charcoal records have been investigated by Unkelbach et al (2018), Unkelbach et al (2019), Unkelbach et al (2020), Unkelbach et al (2021a), and Bruegger et al (2018). There are also records from the Russian Altai (Eichler et al, 2011), the Chinese Altai (Li et al, 2019), and the northern Khangai (Unkelbach et al, 2021b).…”