Spatial pattern of Abies and Picea surface pollen distribution along the elevation gradient in the Qinghai–Tibetan Plateau and Xinjiang, China

Abstract

In this study we examine the relationships between Abies and Picea abundance in surface pollen and sub‐alpine coniferous forest (SCF) distribution, elevation and climate in the Qinghai–Tibetan Plateau using a large modern pollen data set consisting of 857 samples. Results indicate that Abies and Picea pollen are abundant in the southern and eastern Qinghai–Tibetan Plateau, where SCF dominates the landscape. Pollen percentages of both Abies and Picea show a unimodal pattern with changes in elevation and climate, and their optima occur at elevations from 2500 to 4000 m a.s.l., mean annual temperature from −1 to 10 °C and mean annual precipitation from 450 to 850 mm. The optimal elevation of Abies and Picea pollen distribution decreases with latitude from c. 4000 m in the south (21–32°N) to c. 2500 m in the north (43–49°N). The spatial pattern of Abies and Picea pollen abundance is highly correlated with the modern distribution of these taxa, which is largely controlled by elevation and climate. These relationships could provide a practical reference for interpretation of fossil pollen data in terms of climate and elevation in the Qinghai–Tibetan Plateau.

A late Eocene palynological record of climate change and Tibetan Plateau uplift (Xining Basin, China)

“…Pinus pollen can have occurrences of up to 10-50% in the palynological assemblages of deserts and steppe-deserts, where pine trees are absent, as the result of long-distance transport by wind (Ma et al, 2008). However, the abundance of Picea is more significant as Picea pollen distribution in present environments strongly dwindles at any distance from the spruce forests (Lu et al, 2008;Zhou and Li, 2011). The Piceaepollenites percentages (ca.…”

“…and optimally occur at elevations from 2500 to 4000 m.a.s.l. (Lu et al, 2008) together with other high-altitude elements such as Tsuga and Cedrus (Fauquette et al, 2006). Dupont-Nivet et al (2008) therefore suggested that mountain habitat formation was the most likely causes for the Pinaceae increase in the late Eocene record and estimated the minimum palaeoaltitude of 1500 m.a.s.l.…”

“…The general increase of Pinaceae, or 'Pinaceae pollen phase', throughout the Paleogene palynological records has previously been related to global cooling and increased tectonism (Gao et al, 2000). Although Pinus can be transported over long distances (> 1000 km) other conifers such as Picea are much less prone to transport (Lu et al, 2008;Zhou and Li, 2011) and are therefore a good proxy for regional palaeoaltitude especially when found in such high percentages. Pinus pollen can have occurrences of up to 10-50% in the palynological assemblages of deserts and steppe-deserts, where pine trees are absent, as the result of long-distance transport by wind (Ma et al, 2008).…”

“…The onset of the Indo-Asia collision is generally assumed to have occurred during Eocene times with a large range of ages (Tapponnier et al, 1986;Qinghai et al, 2012) including recent paleomagnetic estimates at 49 ± 6 Ma (Dupont-Nivet et al, 2010;van Hinsbergen et al, 2012). After the onset of the collision, there is growing evidence for accelerated intracontinental convergence, deformation and uplift during the Early Cenozoic (Horton et al, 2002;Spurlin et al, 2005;Rowley and Currie, 2006;DeCelles et al, 2007; C. Q. Wang et al, 2008;van der Beek et al, 2009;Song et al, 2010).…”

A 94–10ka pollen record of vegetation change in Qaidam Basin, northeastern Tibetan Plateau

“…The amount of Poaceae and Cyperaceae increased moderately, and Pediastrum proliferated during this period, suggesting lower levels of salinity and relatively higher lake levels. Meanwhile, Picea, which typically found in wet and cool climate, commonly occurring at the elevations from 2500 to 4000 m a.s.l., mean annual temperature (MAT) from − 1 to 10°C and MAP from 450 to 850 mm, reached its highest values (22.5%) (Lu et al, 2004(Lu et al, , 2008. The conditions further indicate that the spruce forest likely occurred in the nearby mountains.…”