Unprecedented recent warming rate and temperature variability over the east Tibetan Plateau inferred from Alpine treeline dendrochronology

Abstract

(0.43 ± 0.08 °C/century, . Our record also displays an enhanced multi-decadal variability since the midtwentieth century. The 1990s-2000s are the warmest of our whole record, due to the superposition of the gradual warming trend and decadal variability during this interval. The strongest decadal cooling occurs during the 1950s and the largest warming trend during the 1970s. The magnitude of warming from 1973 to 2003 was larger than the total warming trend from 1820s to 2009. Extreme events are also more frequent since 1950. The pattern of multidecadal variability has similarities with the Atlantic multidecadal oscillation, suggesting common causality. CMIP5 historical simulations fail to capture both the magnitude and timing of this multi-decadal variability. The ensemble CMIP5 average produces a steady warming trend starting in the 1970s, which only accounts for about 60 % of the observed warming trend during this period. We conclude that TP summer temperature could reflect a climate response to increased greenhouse gas concentrations, however modulated by multi-decadal variations common with the Atlantic sector.Abstract Despite instrumental records showing recent large temperature rises on the Tibetan Plateau (TP), only a few tree-ring temperature reconstructions do capture this warming trend. Here, we sampled 260 trees from seven Alpine treeline locations across the southeast TP. Standardized tree-ring width chronologies of Abies squamata and Sabina squamat were produced following Regional Curve Standardization detrending. The leading principal component of these records is well correlated with the regional summer (JJA) minimum temperature (MinT) (R 2 = 0.47, P < 0. 001,). Hence we produce a regional summer MinT reconstruction spanning the last 212 years. This reconstruction reveals a long-term persistent warming trend, starting in the 1820s, at a rate of 0.45 ± 0.09 °C/ century ). This trend is also detected since the 1820s in the Asian summer MinT reconstruction produced by the PAGES 2K project, with a very close warming rate Electronic supplementary material The online version of this article

Climate change jointly with migration ability affect future range shifts of dominant fir species in Southwest China

“…Additionally, mountains with a substantial elevation range offer short‐distance corridors for the migration of species at a vertical gradient, and these species can recolonize when the temperature becomes more suitable again (Qiu, Fu, & Comes, ). Currently, the MSWC is experiencing an unprecedented warming trend, which is much higher than the global average warming trend over the past half‐century, posing a severe challenge to the survival of mountain plant communities (Alexander et al, ; Shi et al, ). Given the potential risks faced by species in the MSWC, it is necessary to simulate the distribution dynamics caused by ACC in advance.…”

“…Currently, the MSWC is experiencing an unprecedented warming trend, which is much higher than the global average warming trend over the past half-century, posing a severe challenge to the (Alexander et al, 2018;Shi et al, 2015). Given the potential risks faced by species in the MSWC, it is necessary to simulate the distribution dynamics caused by ACC in advance.…”

Significantly lower summer minimum temperature warming trend on the southern Tibetan Plateau than over the Eurasian continent since the Industrial Revolution

“…The temporal variabilities of the TP temperature are seasonally asymmetrical (Xu et al 2017), are sensitive to external climatic forcings including greenhouse gases, volcanic eruptions and energy-absorbing aerosols (Duan et al 2006, Ramanathan et al 2007, Lau et al 2010, Duan et al 2018, and are susceptible to internal variability embedded in the climate system at annual to multi-decadal timescales , Shi et al 2015. Moreover, the warming rates of the TP are spatially inhomogeneous in northern and southern regions , with generally faster warming rates observed at higher elevations (Liu et al 2009, Qin et al 2009.…”

“…Palaeoclimate proxies are widely used to extend climate records back before the beginning of the instrumental records. Among the existing temperature reconstructions for the TP, most use a single record, or a few records, at local or small regional scales, and the results can be strongly biased to the local non-climate signals such as variations in local topography and species competition intensity (Shi et al 2015). This situation can be improved by pooling a larger number of records covering a wider area.…”

青藏高原东北部不同降水梯度下高山林线祁连圆柏径向生长与气候关系的比较

“…With the warming and humidification of the northeastern Qinghai-Xizang Plateau, the climatic limiting factors of tree growth in different timberline areas may be complicated. Key words alpine timberline; climate limiting factors; precipitation gradient; Sabina przewalskii; QinghaiXizang Plateau; tree-ring index Song WQ, Zhu LJ, Zhang X, Wang XC, Zhang YD (2018 (Nemani et al, 2003;Holtmeier & Broll, 2005;Smith et al, 2009;Qi et al, 2015) (王晓春等, 2004;Harsch et al, 2009;Liang et al, 2014;Feurdean et al, 2016;Piper et al, 2016)。然 而, 部分区域林线树木生长对温度敏感性下降或消 失, 甚至由正相关转为负相关, 而对降水的敏感性 却升高 (Wilmking & Myers-Smith, 2008;Solberg et al, 2016), 降水及土壤水分可利用性也可能是限制 林线树木生长的主要因子 Elliott & Baker, 2004;Peng et al, 2008)。Leuschner和 Schulte (1991)提出低纬度干旱区的高山林线树木生 长可能并非由温度控制, 而是由干旱胁迫控制(湿 度限制假说), 在低纬度地区的林线研究中既存在 水分限制树木生长的案例 (Morales et al, 2004;Liang et al, 2014;Piper et al, 2016), 又存在低温限制 树木生长的结果 (Lü & Zhang, 2013) 既存在温度限制也存在水分限制 (Yang et al, 2013;Liang et al, 2014;Shi et al, 2014;Zhang et al, 2014Zhang et al, , 2015aZhang et al, , 2015bZhang et al, , 2016Wang et al, 2015;Yin et al, 2016), 本研究不支持干旱区林线树木生长主要受 水分限制的假说, 但降水量变化会影响林线树木生 长与气温的关系。在本研究中, 降水对不同水分梯 度下林线树木生长的影响方式相同, 但气温主要以 两种方式影响树木径向生长, 分别为: 低温限制作 用 (Shi et al, 2014;Zhang et al, 2014Zhang et al, , 2015aWang et al, 2015;Yin et al, 2016)和高温胁迫作用 (Yang et al, 2013;Zhang et al, 2015b…”