Relationship Between Climate Changes And Tree Ring Width Of Pinus Massoniana And Cryptomeria Fortunei In Longquan Area

This study is focused on Pinus massoniana and Cryptomeria fortunei in Longquan area. We used the growth core to collecting samples from three sample sites. Using ring analyzer to measure the width of the samples, crossing-dating and testing the ring sequence by program COFECHA, finally, using the program ASTAN to remove the trends of all samples and established the tree ring width chronology.Choosing standard chronology as the research object in four chronologies, The statistical characteristics of the data showed that the chronology contains more available environmental information for further study. In two different sampling points, the data of standard chronology statistics characteristics of Pinus massoniana in low altitude was slightly better than the high altitude ones. In similar altitudes, the data of statistical characteristics of Cryptomeria fortunei standard chronology was slightly higher than the standard chronology of Pinus massoniana. It suggests that for the same species, the tree ring of Pinus massoniana contains more environmental information in low altitude areas, the sensitivity of Pinus massoniana in high altitude area to environmental changes was lower. For different species, the sensitivity of Cryptomeria fortunei to the environment was slightly higher than of Pinus massoniana. Through the study on Pinus massoniana and Cryptomeria fortunei, we know that in the low altitude area, temperature mainly play a catalytic role for the growth of Pinus massoniana, The precipitation has distinct restriction effects on the growth of Pinus massoniana radial. In last September, the restrictive effect of precipitation on the growth of Pinus massoniana were particularly obvious. In high altitudes areas, the relationship between Pinus massoniana growth and climatic factors is more complex than the low altitudes areas, and the growth of Pinus massoniana response to temperature are more pronounced. Temperature which plays a role in promoting the growth of Pinus massoniana is mainly reflected in the end of the growing season and the last growing season of medium-term. In September, the ring width has a significant positive response to mean average temperature. Different from Pinus massoniana in low altitude area, in May and last September, precipitation is promotes the growth of the tree. The results of the study showed that the changes of altitude have significant different effects on the growth of Pinus massoniana.Compared with similar altitude area Pinus massoniana, temperature has no significant effect on tree ring growth of Cryptomeria fortunei, Only in last June, the radial growth of Cryptomeria fortunei has a positive response to mean average temperature. Cryptomeria fortunei and Pinus massoniana have different response to temperature. Comparing the responses to precipitation, Pinus massoniana and Cryptomeria fortunei were similar. Similar with the Pinus massoniana, In may and last September, the radial growth of Cryptomeria fortunei has a positive response to monthly precipitation, the radial growth of Cryptomeria fortunei has negative responses to monthly precipitation in march, the difference is that the correlation was not so obvious as Pinus massoniana. Through the study on the Ring width of Pinus massoniana and Cryptomeria fortunei responsing to climate change, it reveals the influence of temperature and precipitation to the radial growth of Pinus massoniana and Cryptomeria fortunei, it’s very important to rebuild the history climate for the study in this area.