Dendroclimatological Analysis of Chinese Fir Using a Long-Term Provenance Trial in Southern China

Abstract

The Chinese fir, Cunninghamia lanceolata (Lamb.) Hook, is an essential fast-growing timber species that is widely distributed in southern China, producing timber with high economic value. Understanding the climate sensitivity of the tree species and its intra-specific variation would help us to estimate the potential climatic adaptation of the Chinese fir. Consequently, we developed radial growth (tree-ring, earlywood and latewood width) and wood density (earlywood, latewood, minimum and maximum density) chronologies for the period 1981–2013 to evaluate whether Chinese fir provenances varied in their tree-ring characteristics and the strength of their responses to seasonal and monthly climate variables. The results showed that more climatic information was obtainable from the trees’ radial growth than from their wood densities. Moreover, the wood density variables provided additional information about seasonal precipitation, which could not be found in tree-ring widths. Specifically, radial growth was highly sensitive to spring and fall temperature, whereas the wood density (particularly that of maximum density) was mainly limited by spring precipitation. Importantly, each tree-ring chronology of Chinese fir provenances varied in the intensity of its response to climate variables, reflecting population acclimation via genetic adaptation or plasticity to local conditions. By providing a theoretical basis for the climate–growth relationships of Chinese fir provenance within a subtropical climate, one can evaluate future climate change impacts on forests and the feedback of forest systems.