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Tree‐ring blue intensity (BI) is well known as a relatively new proxy, which has been utilized for temperature reconstructions over some regions of the worldwide, and has great research potential. In this study, based on tree‐ring data from Pinus massoniana in northwestern Wuyi Mountains in southeastern China, we established a series of tree‐ring width (TRW), earlywood BI (EWBI), latewood BI (LWBI) and delta BI (ΔBI) chronologies. The correlation analysis results indicated that BI chronologies are better than TRW chronology in relation to climate factors; EWBI chronology is a positive correlation with three temperatures (Tmean, Tmax and Tmin), whereas ΔBI and LWBI chronologies almost are negative correlations with temperatures. The LWBI chronology exhibited the highest correlation in July–August Tmin during 1955–2021 (r = −0.61, p < 0.01) and for the reconstruction. The reconstruction model could explain 36.64% of the observed variance. The reconstructed series spanned from 1843 to 2021 and documented three warm periods (1843–1863, 1874–1888 and 1992–2021) and one cold period (1911–1991), and Tmin rapidly warming since 1950s, which is similar to variation in the surrounding temperature reconstruction and is also consistent with the rate of global warming published by the IPCC. The result shows that the summer Tmin anomaly in southeast China is related significantly to the quasi‐biennial oscillation in the western Pacific and Indian Ocean. [ABSTRACT FROM AUTHOR]

Humid subtropical China is an "oasis" relative to other dry subtropics of the world due to the prevailing of the East Asian summer monsoon (EASM). Although many long climate sensitive tree-rings have been published to understand the historical climate change over various regions in China, long tree-ring chronologies in humid subtropical China are rare due to the difficulty to find old growth trees. This study established a tree-ring chronology spanning from 1776 to 2016 from Cryptomeria fortunei Hooibrenk ex Otto et Dietr in Liancheng area of humid subtropical China, which is also currently the longest chronology in Fujian province. Similar to the climate-growth relationships in neighboring regions, our tree-ring chronology is limited by cold temperature in winter and spring and drought in summer. In addition, a drought stress before the growing season also played a role in limiting the growth of our tree rings. Our climate sensitive tree rings showed different correlations with the Pacific Decadal Oscillation (PDO) in different periods, possibly via modulation of the EASM. [ABSTRACT FROM AUTHOR]