Determination and climatic response of growth release/inhibition of diecious species

With diecious species of Populus davidiana, Fraxinus mandshurica and Taxaceae chinense in Changbai Mountains of northeastern China as research objects, the relationships between growth release/inhibition of diecious species and climatic factors were determined to reveal the effects of species’ properties and gender on the growth release/inhibition and the differences on climate response mechanism by tree ring method. Results showed that the growth release/inhibition of 3 tree species occurred in the period of young age. The physiological differences might cause the diversities on the frequency and time of growth release/inhibition. The gender significantly influenced the growth release/inhibition of P. davidiana and T. chinense. The female P. davidiana and the male T. chinense were much sensitive to environmental disturbance. There was no obvious difference in the growth release/inhibition between male and female of F. mandshurica. Among 3 diecious species, the growth release of P. davidiana much easily occurred by environmental disturbance. The F. mandshurica growth event was possibly related to forest gap disturbance. The growth release/inhibition of P. davidiana and T. chinense were significantly correlated with climatic factors. The growth of male T. chinense was in significantly positive correlation with temperature and precipitation (P0.05), and however negatively for male P. davidiana (P0.05). The growth of female P. davidiana was in significantly negative correlation with precipitation (P0.05). The response of growth release/inhibition to climate was different from the relationship between radial growth and monthly climatic factors. Therefore we should consider the non-linear relation of radial growth-climatic factor and the effect of species’ properties and gender on the relationships between growth-climate for improving the response mechanism of trees to climate.