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In this paper, we present a late summer (August-September) temperature reconstruction over the period 1792-2020 based on a tree-ring maximum latewood density (MXD) chronology for the southern Tibetan Plateau (TP). The reconstruction explained 66.2% of the variance in the instrumental temperature records during the calibration period 1960-2020 and captured the warming trend since the 1960s, which would support the current warming on the TP. In addition, a warming hiatus existed during 2001-12 and the last 20 years (2000-20) were the warmest period in the past two centuries. The reconstruction matched other MXD- and mean latewood density (LWD)-based late summer temperature reconstructions from neighboring regions, and fluctuated in synchrony with the Climatic Research Unit (CRU) Northern Hemisphere land surface temperature during 1850-2020. Multitaper method analysis and wavelet analysis revealed significant periodicities of 2-3, 20-30, and 40-60 years in the reconstructed series. Our reconstructed series was very consistent and highly correlated with the Atlantic multidecadal oscillation (AMO). During the warm phase of the AMO, higher pressure and divergent horizontal winds over the TP contribute to warmer summers in the region. In addition, we found that the southern TP experienced the lowest temperature and downward solar radiation in the second year following large volcanic eruptions. The decrease in downward solar radiation may be directly responsible for the occurrence of the lowest temperatures. The results indicate that the AMO and large volcanic eruptions were impacting factors on temperature in our study area. [ABSTRACT FROM AUTHOR]

Little is known about the spatial variability in tree growth and its responses to climate on the Tibetan Plateau; however, such information is essential for improving predictions of forest ecosystem response to climatic change. A network of 16 ring width chronologies was developed along a latitudinal transect in the Qilian Mountains, northeastern Tibetan Plateau. A principal components analysis revealed that the residual chronologies had a positive loading on the first unrotated principal component (PC1). After rotation, PC1 yielded the highest loadings on the driest sites in the northwest and decreased to the south and to the east. PC2 was negatively correlated with altitude. Moisture availability was a dominant limiting factor for tree growth, and this dominance increased northwards and westwards along the precipitation gradient. Loadings of the first two rotated principal components separated the 16 forest sites into three major groups corresponding to the three regions affected by the East Asian Monsoon, Westerlies, and their interaction. Thus, spatial variability in tree growth is an excellent bioindicator of regional climate. [ABSTRACT FROM AUTHOR]

The article discusses about the effects of temperature and precipitation changes in time on the tree growth of Qilian junipers (Sabina przewalskii Kom.), found along the Qinghai-Tibetan Plateau. According to the article, studies before had shown that water usage stress is the most restraining factor for the growth of trees in the Qaidam Basin region. A water balance modelling using a 1955-2002 meteorological data was used to evaluate the impacts of changes in temperature and precipitation. From the experiment conducted, it was concluded that the climate variability at the interannual and interdecadal scales are reflected by moisture conditions reconstructed from tree-ring widths.