Elevational Heterogeneity in Radial Growth-climate Association of Pinus massoniana in Southeastern China

Abstract:

To achieve a better understanding about the elevation heterogeneity in tree growth-climate association in southeastern China, four tree-ring width chronologies of Pinus massoniana from eastern foot of Wuyi Mountains in Fujian were established, and the relationship between radial growth and climate factors along elevation were investigated by bootstrapped correlation analysis and linear mixed effect model (LME). The results showed that radial growth of trees at higher elevation had higher sensitivity to climate and higher consistency between sites, mainly reflected as the positive correlations with the winter-spring temperature/sunshine conditions and precipitation in July. Moreover, the linear mixed effect model using three monthly climate factors, such as monthly mean daily maximum temperature in last December, monthly total sunshine hours in current January, and monthly total precipitation in current July, can explain 50% of total variance of radial growth at higher elevation, and the both fronts play a leading role in the model with cumulative relative contribution rate of 80%. So, it was suggested that the pre-growing season temperature/sunshine condition are the main factor regulating tree radial growth at high elevation, and that these trees might have higher sensitivity to future climate changes and forest management policies should take this into account. Moreover, the results showed that the trees at high elevation in subtropical forest had the potential to be used for tree ring-climate reconstruction.

Key words:Pinus massoniana;Radial growth;Subtropical forest;Elevation;Climate;LME model;China