TEMPERATURE AND RAINFALL IN RELATIONSHIP WITH RING DENSITY AND RING TOTAL NITROGEN OF Pinus merkusii IN THE CENTER OF VIETNAM

Tree growth is affected by the environment changes. Mean temperature and annual rainfall at Quang Binh province were used to be representatives of climate. Tree ring density (TRD) and tree ring total nitrogen (TRTN) show the tree growth of pine merkusii in Quang Binh of Vietnam. This paper aimed to study influence of mean temperature and rainfall on TRD and TRTN. Physical method was applied to analyze density based on Archimedes principle and chemical method was used to analyze total nitrogen in the Lab of Institute for Agricultural Environment (IAE) by using the standard of Chonnam National University (CNU) Lab. Tree growth (TRD and TRTN) depends on temperature or rainfall in an linear equation. The results in 12 months of a year showed that August was the most sensitive month relating to environment change and tree growth. The correlation between monthly average temperature and TRD (R square = 0.75**) and TRTN (R square = 0.84**) was positive. The correlation equation between mean temperature and TRD and TRTN was Y = 0.49X1 + 11.97X2 + 26.4. There was no significant correlation between rainfall and TRD and TRTN. In conclusions, the result was meaningful for interpolating the environment change (mean temperature) from tree ring disk (TRD and TRTN) in a linear equation. Y = 0.49X1 + 11.97X2 - 212337