祁连山东部地区树木年轮年表的建立

利用采自祁连山东部的祁连圆柏样芯,经常规程序晾干、固定、打磨、定年和读数后,建立了标准化年表,并将标准年表的树轮指数与采样点附近的天祝乌鞘岭气象站的温度和降水进行了相关分析。结果表明,年轮指数与3~4月降水呈显著正相关,相关系数达0.525。由于3~4月份的降水为该地区树木生长季之初的降水,是树木生长的限制因子,因此该相关具有明确的生物学意义。研究还发现,年轮指数与1月气温也呈显著负相关(相关系数为- 0.297),这可能是由于冬季最冷月气温偏高时,影响树木代谢和土壤湿度,从而影响树木的生长。祁连山东部地区树木年轮年表具有明确的气候学意义。

The Establishment of Tree-ring Chronology in East Region of Qilian Mountains

The standardized(STD) chronology was established from tree ring data of Sabina przewalskii in east region of Qilian Mountains. The correlation between the tree ring index and the precipitation and air temperature of Wushaoling station which very near the sample site was analyzed. The results indicated that there is positive correlation between tree ring index and the precipitation of March and April. The correlation coefficient R is 0.525. It can be explained that the precipitation at the early growing season benefits the tree's growth. Because the precipitation of the study region is affected by summer monsoon, the precipitation is sufficient for the plant growing in summer. But it is insufficient in spring, and this season is very important for the plant. With the rising of air temperature the plant begin to grow, so the precipitation is very important for them. There is negative correlation between the tree ring index and the air temperature of January. The correlation coefficient R is -0.297. This perhaps because the high air temperature affects the metabolism of trees and the humidity of soil, therefore the growth of trees was affected at last. In winter the respiration of the trees keep on a low level, but it doesn't stop. When the air temperature is relatively high in winter, it inspires the respiration of the trees and the metabolism rises to a relatively high level. By this way the nutrition stored in the trees are wasted, which affects the growth of trees next year.