华北区域杨柳科树木春季物候期模拟

Simulation of spring phenology of Salicaceae trees in North China

杨柳科树木是我国华北区域植树造林的主要树种,但春季的杨柳飞絮问题既影响区域大气环境质量,也对人体健康造成一定的危害,因此准确预报杨柳科树木的春季物候期具有重要现实意义。基于中国气象局农业气象观测网和中国科学院地理科学与资源研究所中国物候观测网提供的华北区域1963—2018年59个站点的4种杨柳科树木(垂柳、旱柳、加拿大杨、毛白杨)的4个春季物候期(开花始期、盛期、末期和果实或种子成熟期)观测数据,对3种基于逐日气温序列构建的春季物候过程模型(简单积温模型、温度三基点模型和冷激-三基点模型)进行了参数率定和优选,分别对这16个基于物种-物候期的最优春季物候模型进行了外部检验。内部模拟结果表明,各模型对同一物种-物候期模拟效果相差不大,均方根误差(RMSE)介于5.5—11.6d,各模型对同一物种发生较早的物候期模拟效果相对更好。通过赤池信息准则(AIC)判定,上述16个基于物种-物候期的最优春季物候模型中,有11个选择简单积温模型,有5个选择冷激-三基点模型,其中,垂柳和旱柳的最优春季物候模型都选择了简单积温模型,加拿大杨的各春季物候期对2种物候模型均有选择,毛白杨的各春季物候期则全部选择了冷激-三基点模型,表明对于大多数柳属树木的春季物候期的模拟只考虑春季气温即可,而对于杨属树木的春季物候期则需考虑冷激过程的影响。研究可为华北区域乃至我国北方温带地区的杨柳飞絮预报业务化奠定基础。

Salicaceae trees are the main tree species for afforestation in North China region,but the spring poplar flocculation problem has an effect on the regional atmospheric quality and causes certain harm to human health.So it is of great practical importance to accurately forecast the spring phenological stages of Salicaceae trees.In this study,we used the observations of four spring phenological stages(beginning of flowering,full flowering,end of flowering,and fruiting)of four Salicaceae trees(Salix babylonica Linn.,Salix matsudana Koidz.,Populus×canadensis Moench,and Populus tomentosa Carrière)at 59 stations in North China in 1963—2018.The phenological data was provided by the Agricultural Meteorological Observation Network from China Meteorological Administration and Chinese Phenological Observation Network from Institute of Geographic Sciences and Natural Resources Research.Using the phenological data,three models of spring phenological processes based on daily temperature series(TT,PT,PTc)were parameterized and selected.Finally,16 optimal spring phenological models based on species-phenology were conducted for the external validation.The internal validation results showed that the three models based on temperature did not differ significantly in simulating the same species-phenology,with RMSE ranging from 5.5 to 11.6 days.Each model was relatively better in simulating the earlier phenological stages of the same species.According to Akaike information criterion(AIC),among the above 16 models,11 were TT models,and 5 were PTcmodels.What's more,Salix babylonica Linn.and Salix matsudana Koidz.all selected TT model as the optimal for all the four phenological stages,Populus×canadensis Moench selected both TT and PTc models,and Populus tomentosa Carrière selected PTcmodel for all the four spring phenological stages.It is suggested that many spring phenological simulations of Salix trees could only consider spring temperature,while for Poplar trees,the influence of chilling should be considered.This study could lay the foundation for the operationalization of Salicaceae tree flutter forecasting in North China region and even in the northern temperate area of China.