NOAA/WDS Paleoclimatology - Römer - Asco Valley - PINI - ITRDB FRAN051

Maximum latewood density (MXD) measurements from long-lived Black pines (Pinus nigra spp. laricio) growing at the upper treeline in Corsica are one of the few archives to reconstruct southern European summer temperatures at annual resolution back into medieval times. Here, we present a compilation of five MXD chronologies from Corsican pines that contain high-to-low frequency variability between 1168 and 2016 CE and correlate significantly (p < 0.01) with the instrumental April-July and September-October mean temperatures from 1901 to 1980 CE (r = 0.52-0.64). The growth-climate correlations, however, dropped to -0.13 to 0.02 afterward, and scaling the MXD data resulted in a divergence of >1.5 C between the colder reconstructed and warmer measured temperatures in the early-21st century. Our findings suggest a warming-induced shift from initially temperature-controlled to drought-prone MXD formation, and therefore question the suitability of using Corsican pine MXD data for climate reconstruction.

生长于科西嘉岛林线上限的长寿黑松（Pinus nigra spp. laricio）的最大晚材密度（Maximum latewood density, MXD）序列，是少数可按年分辨率重建中世纪以来南欧夏季温度的气候档案之一。本研究汇编了5组来自科西嘉松的MXD年表，这些年表涵盖公元1168年至2016年间的高低频气候变化信号，且与公元1901年至1980年的器测4-7月及9-10月平均温度呈显著相关（p < 0.01，相关系数r=0.52~0.64）。然而在此之后，树木生长与气候的相关性降至-0.13至0.02；对MXD数据进行尺度校准后发现，21世纪初重建温度较器测温度偏低，二者偏差超过1.5℃。本研究结果表明，气候变暖导致MXD形成机制从最初的温度调控主导转变为易受干旱胁迫影响，因此对利用科西嘉松MXD数据开展气候重建的适用性提出了质疑。