中文摘要：

树木年轮（树轮）密度即木材密度,是历史气候和环境演变研究中使用的重要代用资料之一,在揭示北半球长时间尺度夏季温度变化和火山喷发的研究中发挥了不可替代的作用.近十年来,我国的树轮密度研究迅速发展,取得了长足进展.本文将对树轮密度测量技术和方法的发展历程进行概述,对国际和国内树轮密度研究取得的重要成果进行总结.通过对一些热点和争论性问题的论述,进一步明晰树轮密度的研究潜力,旨在为今后的研究提供背景参考.

英文摘要：

Tree-ring density （i.e., wood density） is one of the most important proxies for climate reconstruction and environment change study. Generally, seven parameters of tree-ring data （i.e., earlywood and latewood widths, mean earlywood and latewood densities, maximum and minimum densities, and total tree-ring widths） can be obtained by tree-ring density measurement. Tree-ring density, especially maximum latewood density （MXD） has been widely used on summer temperature reconstruction and volcanic eruption study in the North Hemisphere. Climate warming in the 20th century and the anomalous temperature increase in the recent period have been suggested by many temperature reconstructions based on tree-ring density data. Over the past decade, tree-ring density research experienced a fast development in China and great advances have been achieved. Some studies indicated that tree-ring density, including mean earlywood density, minimum earlywood density and MXD in several tree species in the Northwestern China were correlated with precipitation in spring or annual precipitation. But, MXD in the Northeastern China and the Tibetan Plateau significantly correlated to summer temperature variability. Thus, precipitation reconstructions based on tree-ring density data have been performed in the Northwestern China and summer temperature variability has been reconstructed both in the Tibetan Plateau and the Northeastern China. The variance explained by the model in the instrumental period is relatively higher in the Tibetan Plateau than in Northwestern and Northeastern China. Additionally, tree-ring density data also were casually used in the other areas. For example, glacier mass balance reconstruction, air pollution and so on. In this paper, the methods used for measurement of tree-ring density （e.g., X-ray measurement, high-frequency densitometry, blue reflectance and so on） are summarized, and the important results obtained based on tree-ring density in the North Hemisphere and China are reviewed. After a stat