中文摘要：

基于1982-2006年内蒙古地区17个小白杨物候观测站的气温以及小白杨春季和秋季物候资料，对该区小白杨春季和秋季物候的变化趋势进行了研究，分析了物候期变化与气候变暖的关系，并利用逐步回归方法建立了小白杨始花期和落叶期变化的预估模型．结果表明：1982-2006年间，研究区气温呈增加趋势，该区小白杨春季物候呈提前趋势，秋季物候呈延后趋势；小白杨始花期与冬、春季气温呈负相关，主要影响因子为3—14月的平均气温；落叶期与秋季气温呈正相关，主要影响因子为8—10月的平均气温；根据气候变化国家评估报告，未来内蒙古地区春、秋季平均气温分别升高1．5℃～5．4℃和1．2℃～4．4℃，小白杨始花期将提前3．9～17．8d，落叶期将延后3．0～12．4d．

英文摘要：

Based on the 1982-2006 data of air temperature and of the phenophase of Populus tomentosa in spring and autumn from 17 phenological observation stations in Inner Mongolia, the change trend of the phenophase of P. tomentosa in spring and autumn was studied, and its relations to climate warming were analyzed. The models for predicting the date change of P. tomentosa first flowering and defoliating were constructed by stepwise regression method. It was shown that from 1982 to 2006, the air temperature in study area was increased, and the date of first flowering and defoliating of P. tomentosa was advanced and postponed, respectively. The first flowering of P. tomentosa was negatively related to the air temperature in spring and winter, and the main affecting factor was the air temperature from March to April; while the first defoliating of P. tomentosa was positively related to the air temperature in autumn, and the main affecting factor was the air temperature from August to October. According to the national assessment report on climate change, the air temperature in Inner Mongolia in spring and autumn would be raised by 1.5℃-5.4℃ and 1.2℃-4.4℃, and the first flowering and defoliating of P. tomentosa would advance 3.9-17.8 days and postpone 3.0-12. 4 days, respectively.