An 850‐year tree‐ring‐based reconstruction of drought history in the western Qilian Mountains of northwestern China

Abstract

Studies of regional drought history will be helpful for understanding current hydroclimate variability with global warming as well as predicting future hydroclimate shifts. Long‐term tree‐ring records are scarce in the western Qilian Mountains of northwestern China, which is also the western boundary of the natural distribution of Qilian Juniper (Juniperus przewalskii Kom.) in this area. Here, we present an 850‐year (AD 1161–2010) reconstruction of May–July self‐calibrating Palmer Drought Severity Index (scPDSI) in the western Qilian Mountains that is based on two nearly millennia of ring‐width chronologies derived from long‐lived Qilian Juniper trees. The reconstruction suggests a relatively dry phase from the 15th century to the 18th century during the Little Ice Age (LIA) and a relatively wet period over the past two centuries. This reconstruction is consistent with other tree‐ring‐based hydroclimatic reconstructions from the northeastern Tibetan Plateau, as well as the corresponding century‐scale solar activity during the LIA. The three mega‐drought periods (AD 1260s–1340s, 1430s–1540s and 1640s–1740s) recorded by the tree‐ring series also correspond to the Wolf, Spörer and Maunder solar activity minimum periods. Results of the multi‐tape method analysis and wavelet analysis further confirmed the relationship between regional hydroclimate variability and solar activity forcing.

Which climatic factors limit radial growth of Qilian juniper at the upper treeline on the northeastern Tibetan Plateau?

“…In addition, high temperature in May leads considerable evaporation from the soil and transpiration from leaves, causing drought stress on cambial activity. However, the influence of drought is not as strong as that reported in other studies at lower elevations (Gou et al, 2014;Liu Lusan et al, 2006;Shao et al, 2005;Zhang et al, 2003), suggesting that more soil moisture is available at high elevations due to lower evaporation and higher precipitation. Thus, the moisture-triggered onset of cell division could only play a weaker role than low temperature in controlling the whole ring width of Qilian juniper at the upper treeline.…”

Drought fluctuations based on dendrochronology since 1786 for the Lenglongling Mountains at the northwestern fringe of the East Asian summer monsoon region

“…8; Zhang et al, 2013;Chen et al, 2015;, and were significantly increasing in the western and middle Qilian Mountains (T11 and T12; Fig. 8; Gou et al, 2015b). In contrast, moisture conditions in the LLM presented an opposite trend (LLM; Fig.…”

“…A PDSI dataset on a 2.5°×2.5° grid that was developed by Dai et al (2004) had been widely used as the variable of climate reconstructions (Cook et al, 2004;Nicault et al, 2008;Peng and Liu, 2013;Gou et al, 2015b). The newly revised sc_PDSI index improves its ability to measure changes in aridity and to examine the effects of individual forcing on the aridity trend (Dai, 2012).…”

Precipitation reconstruction for the northwestern Chinese Altay since 1760 indicates the drought signals of the northern part of inner Asia

“…Inner and northern Asia is also one of the most sensitive areas to climate change in Asia, and many treering-based climate reconstructions have been conducted in this area (Briffa et al 1995;Esper et al 2001Esper et al , 2010Pederson et al 2001;Solomina et al 2007;Agafonov and Kukarskikh 2008;Magda et al 2011;Chen et al 2013Chen et al , 2015Liu et al 2013;Gou et al 2014;Bao et al 2015). Dendroclimatological studies at the high-latitude sites of northern Asia have been focused on temperature reconstruction and provided the information about the summer temperature variations and recent global warming (Briffa et al 1995(Briffa et al , 2013Naurzbaev et al 2002;Esper et al 2010).…”

“…Some studies revealed that the role of temperature as a limit factor of tree growth was shown to decrease from high latitude to low latitude (Fritts 1976;Hantemirov et al 2000;Agafonov and Kukarskikh 2008;Kucherov 2010;Briffa et al 2013). On the contrary, the effect of drought and precipitation on tree growth was increased gradually from northern Asia to inner Asia (Pederson et al 2001;Magda et al 2011;Chen et al 2013Chen et al , 2015Liu et al 2013;Gou et al 2014;Bao et al 2015). In recent years, some dendroclimatic reconstruction precipitation and drought index have also been developed from lower elevation sites at the junction area of inner and northern Asia where the forest vegetation is in contact with the steppe vegetation (Davi et al 2009;Kucherov 2010;Chen et al 2014;Zhang et al 2014).…”