帽儿山地区兴安落叶松人工林树木年轮气候学研究

Tree-ring Climatology of Larix gmelinii in Maoershan Region,Northeastern China

通过帽儿山兴安落叶松(Larix gmelinii)人工林树木年轮样本和气象资料,对该地区兴安落叶松进行了树木年轮气候学研究,结果表明:过去50年年均温度上升达到了显著水平(p<0.05),平均温度每10年约上升0.4℃,年平均最高气温每10年约上升0.3℃,年平均最低气温每10年约上升0.5℃,但是年降水量随着年份变化不显著(p>0.05)。从月均温度来看,所有月份均出现明显上升趋势,其中冬季2月份温度上升最为明显,达到0.9～1℃/10年,而夏季(6～8月)上升的较小,达到0.2～0.7℃/10年;多数月份降雨量随年龄变化不显著(p>0.05)。在这一气候变暖过程中,早材及总年轮宽度生长随着夏季(6～7月)温度上升而下降,春季(5月)温度的升高而升高,晚材随着秋季(9月)温度上升而增加,导致在年水平上,年轮生长随着年均温的变化不显著(p>0.05)。降雨量在未来气候变化过程中,没有稳定的变化趋势,但是对年轮影响明显,在年水平上,早材与年轮的生长均受降水量的影响较大(p<0.05)。如果未来东北地区气候变暖趋势明显,而降水量变化不明显,春季和秋季温度升高导致的年轮生长增加会被夏季过高温度抑制年轮生长所抵消,因此,落叶松林径向生长受到的影响可能不大。

Through collecting the meteorological data, sampling and standardizing the data of tree rings of larch （Larix gmelinii）, the climatic changes in Maoershan region were analyzed and their influences on tree ring fea- tures were studied in this paper. In the past 50 years, significant increases in temperature were found （p 〈 0. 05 ） , i.e. about 0.4℃per decade in average annual temperature, 0.3℃ per decade in average annual maxi- mum temperature as well as 0.5℃ per decade in annual average minimum temperature were observed. However, no significant change in annual precipitation was found （p 〉 0.05 ）. Average monthly temperature （average tem- perature, average maximum temperature, average minimum temperature） also showed increasing tendencies and the most significant month was in February of the winter, about 0.9 - 1 ~C per decade. Much smaller temperature increases, ca. 0.2 -0.7~C per decade was found in June to August of the summer）. No significant change in monthly precipitation was found in most months （p 〉 0.05）. During the coming climate warming, widths of early and whole tree rings （p 〈0.05） might be decreased with the temperature increment in summer （June to July） , while widths of early and the growth of tree rings would increase with the temperature increases in spring （May）. The width of late might be increased with the temperature increases in autumn （September）. These might cause the non-obvious chane in ring width with nnn..fo t h （P〉0.05）Alhtough non-significant;changes in precipitations, the significant correlations between annual precipitation and variable tree rings indices indicated the growths of early wood and whole tree rings might be positivity affected by the amount of annual pre- cipitations. Considering the warming trend of the climate change is significant in northeast China in future but the rainfall does not. The growth of tree rings caused by spring and autumn temperatures could be offseted by too high temperatures in summer which inhibited the tree ring growth. Therefore, the influence on the radial growth of the Larix might be httle.