关键词: 春季气温, 树木年轮, 甘肃榆中

Abstract: Tree-ring increment cores were sampled at Xinglongshan Mountain in Gansu Province. The object of this research is to study the relationship between tree-ring and climate factors, and to analysis the past 200 years climate change. There is positive correlation between tree-ring index and spring temperature. The correlation coefficient is 0.429, which is significant at the 0.01 level. The tree-ring width is limited by spring temperature. According to the tree-ring data, the change of spring temperature for the period A.D.1800 to 1999 shows four cold and three warm periods in the low frequency variations of 11 years moving average since A.D.1800. The result indicated that the Yuzhong area was mainly in a warm state since A.D.1800.After analyzing periodic characteristics, we find that spring temperature since A.D.1800 has 60 years periods and 15 years periods.Seen from the large scale for the last 200 years, there is no obvious warm or cold tendency for spring temperature, but take on an alternative form. Contrasting to the climate change of neighboring area, we find that warm periods correspond well with those of Hengduan Mountains and Xizang.

Key words: spring temperature, tree ring, Yuzhong in Gansu province