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A Dendroclimatic Study of Relic Picea meyeri in Inner Mongolian Steppe


Dendroclimatic methods were used to investigate the fundamental relationships between the temperature variables and the growth of climatically relic Picea meyeri Rehd. et Wils. on sandy land of Inner Mongolian grasslands in the Xilin River Basin. The annual mean temperature and accumulated temperature (above 5 ℃, 10 ℃) respectively showed no significant correlation with the spruce growth relative to summer mean temperature, which displayed strong coherence with tree growth ( P <0.01). The mean temperature in May showed significantly negative correlation with spruce growth ( P <0.05). Furthermore, it was revealed that the negative influence of May temperature was due to monthly mean maximum temperature ( T max) ( P <0.01) other than monthly mean minimum temperature ( Tmin) values ( P <0.1), which indicated that the use of Tmin and T max separately can allow much more insights on the temperate influence. In addition, extreme maximum temperature in May and June might impose the most detrimental influence on tree growth in semi-arid Inner Mongolian grassland. The analysis of the recorded meteorological data demonstrated that the increases in temperature were synchronous with slight decreases in precipitation in the growing season, which suggested that P. meyeri may reduce growth due to temperature-induced drought. On the other hand, the analysis for decadal periods explored that trees appeared to reduce the sensitivity to the warming, and consequently increased sensitivity to rainfall. This may serve as a baseline for more accurate predictions of the potential impacts of altered climate regimes on tree growth.

内蒙古草原残遗白木千的树木年轮气候学研究
梁尔源1 邵雪梅2 胡玉熹1 林金星1*

(1. 中国科学院植物研究所,北京100093;2. 中国科学院地理研究所,北京100101)

摘要:运用树木年轮气候学的方法研究了内蒙古锡林河流域典型草原上残遗白木 千(Picea meyeri Rehd.etWils.)的生长与气温要素间的关系。每年5月份的平均温度(P<0.05)和平均最高温度(P<0.01)与白的生长关系密切,而近40年来的年平均气温以及高于5℃、10℃的积温与白木 千的生长间无显著的相关关系。另外,5、6月份的极端最高温度对树木的生长也具明显的负效应(P<0.05)。从1954年至1994年来,锡林河流域典型草原增温明显,其中以10年段资料的相关分析则表明,随气温的升高,白的生长对温度的敏感度有下降的趋势,揭示的这一现象,对于更准确地预测未来环境变化对森林分布和生产力的影响,以及环境模式参数的优化等均具一定的指导意义。

关键词: 白木千;树轮气候学;气温变量


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