黑龙江漠河兴安落叶松与樟子松树轮生长特性及其对气候的响应

 树木年轮(简称树轮)气候学是监测与重建全球气候变化的重要方法之一。针叶树树轮的生长能反馈出气温的变化，在高纬度地带尤为明显。该文分析了生长在我国最北部的兴安落叶松（Larix gmelinii）与樟子松(Pinus sylvestris var. mongolica)的树轮密度和宽度的特性。落叶松最大密度、晚材平均密度、早晚材宽度和轮宽都远高于樟子松。樟子松的所有密度变量的样本方差都明显高于兴安落叶松，宽度变量的样本方差却明显低于兴安落叶松。两树种密度变量的差值年表显著相关，宽度变量之间没有显著相关关系。落叶松与樟子松的晚材密度的形成受7、8月的最高温控制。另外，樟子松的晚材还与生长季节的长短相关。落叶松的年轮宽度对生长季节开始前的温度敏感，而樟子松的轮宽对气候变量没有很好的响应。结果表明，落叶松与樟子松的树轮最大密度都与生长季后期的温度显著相关，两树种的树轮信息对气候变化的重建有很大的潜力。

TREE-RING CHARACTERISTICS OF LARIX GMELINII AND PINUS SYLVESTRIS VAR. MONGOLICA AND THEIR RESPONSE TO CLIMATE IN MOHE, CHINA

Dendroclimatology is one of the most important methods for monitoring and reconstructing global climate change. Variations of tree-ring growth in conifers reflect temperature fluctuations, especially in high latitude regions. Larix gmelinii and Pinus sylvestris var. mongolica are two major conifer species in boreal forests in the northernmost region of China. Densitometry was used to analyze tree-ring width and density in these two species in Mohe, Heilongjiang Province, China. Seven tree-ring variables (maximum density, minimum density, mean earlywood density, mean latewood density, earlywood width, latewood width and annual ring width) were investigated using Dendro2003 and compared with meteorological data from a weather station near the sampling site. The maximum density, mean latewood density, earlywood width, latewood width and annual ring-width in Larix gmelinii were higher than those in Pinus sylvestris var. mongolica. However, the variance among all the densitometric variables in Pinus sylvestris var. mongolica was significantly higher than that in the Larix gmelinii, but the variance of total ring width was different. Both residual chronologies of tree-ring density were significantly correlated but no significant correlations were found between the tree-ring width chronologies of the two species. The maximum temperature controlled the latewood density of both species in July and August. In addition, the latewood density of Pinus sylvestris var. mongolica was closely related to the length of the growing season. Correlation analysis also demonstrated that the annual ring widths of Larix gmelinii were sensitive to the temperature at the beginning of the growing season, but the ring widths of Pinus sylvestris var. mongolica did not have any significant climatic response. In summary, although Larix gmelinii and Pinus sylvestris var. mongolica had different tree-ring growth patterns, the tree-ring maximum density of these two species was highly responsive to temperature in the late growing season. The dendroclimatic growth characteristics of these two species have potential for reconstructing climate in this region.