气候变化对大兴安岭西麓林牧交错带木本植物物候期的影响

为了揭示气候变化背景下林牧交错带木本植物物候期的变化趋势及对气候变化的响应,为林草交错带固沙防风等生态恢复工程提供科学气象参考依据,利用内蒙古呼伦贝尔市鄂温克牧业气象试验站1994—2019年观测的榆树、小叶杨和紫丁香3种木本植物物候观测资料及同期气象数据,采用线性倾向估计、Pearson 相关系数、散点图等方法,分析了近26 年气候变化对大兴安岭西麓林牧交错带木本植物物候期的影响。结果表明：近26 年,大兴安岭西麓植物生长季气温显著升高,降水变化趋势不明显。榆树、小叶杨和紫丁香3种木本植物花芽开放期提前,落叶末期推后,且落叶末期推迟天数较多,平均每10 年分别推迟9.6、7.5 和8.5天。生长季显著延长,平均生长季分别为160~164天。气温是影响榆树、小叶杨和紫丁香春季花芽开放期和秋季落叶末期的关键气象因子。3种木本植物春季花芽开放期的提前对温度上升的响应是显著负相关关系,落叶末期推后对温度上升的响应显著正正相关关系。说明气候变暖背景下,3种木本植物花芽开放期提前,落叶末期推迟,生长期长度增加;且推迟天数较花芽开放期提前天数更大,说明气候变化对木本植物落叶末期影响更明显,落叶末期对生长季长度增加的贡献更大;大兴安岭西麓林牧交错带木本植物物候期的变化主要是受气温的影响,与降水量关系不大。

Effects of Climate Change on Phenophase of Woody Plants in the Forest-Pasture Ecotone at the Western Foot of the Great Khingan Mountains

The purpose of the study is to reveal the change trend of woody plants’ phenophase and its response to climate change in the forest-pasture ecotone, and provide meteorological reference for guiding the ecological restoration projects of sand fixation and wind prevention. The phenophase observation data of three kinds of woody plants, Ulmus pumila, Populus simonii Carr and Syringa oblate, and simultaneous meteorological data from Ewenki meteorological experimental station in Inner Mongolia from 1994 to 2019 were used to analyze the influence of climate change on the phenophase of woody plants in the forest-pasture ecotone at the western foot of the Great Khingan Mountains by linear tendency estimation, Pearson correlation coefficient, scatter diagram and other methods. The results showed that in the 26 years, the temperature increased significantly in the plant growing season in this region, and the change trend of precipitation was not obvious. The flowering period of Ulmus pumila, Populus simonii Carr and Syringa oblate was earlier, and the late abscission period was postponed by 9.6, 7.5, and 8.5 d every 10 years, respectively. The growing season was prolonged significantly, and the average growing season was 160-164 d. The air temperature was the key meteorological factor affecting the flowering period in spring and the late abscission period in autumn. The advanced flowering period of the three woody plants had a significantly negative correlation with the rise of temperature in spring, and the postponing of the late abscission period was significantly and positively correlated with the rise of temperature. In conclusion, under the background of climate warming, the earlier flowering period and the delayed late abscission period of the three woody plants have been observed, and the growth period is extended. The postponing days of the late abscission period are more than the earlier days of the flowering period, indicating that climate change has a more obvious impact on the late abscission period of woody plants, and the late abscission period has a greater contribution to the extension of the growing season. The phenophase change of woody plants is mainly influenced by temperature and has little correlation with precipitation in the forest-pasture ecotone at the western foot of the Great Khingan Mountains.