Analysis on the Characteristic of Spring Temperature Fluctuation during Late Spring Frost on Ornamental Trees in Beijing

LAN Xin;LIU Yang;ZHANG Yu;WEI Hong-xu;West Mountains Experimental Tree Farm;The Ming Tombs Tree Farm;Northeast Institute of Geography and Agroecology;

Late-spring frost;;Sub-zero temperature in spring;;Climatic change;;Ornamental plants;;Phenology dynamic;;Alert for natural hazard

[Objective]To study city garden trees suffered frost in spring late spring coldness temperature characteristics in Beijing.[Method]Spring temperature in Beijing was analyzed according to the characteristics of late spring frost( LSF) in temperate area in 2011- 2016. The potential threat of LSF was predicted on ornamental trees based on the component of their species in large parks of constructed areas of Beijing.[Result]LSF usually resulted in significant effect on trees by a sudden decline to temperature to sub-zero following a warm spell for at least five days in temperate forests at around the north latitude of 40 ° before the start of spring phenology. Accordingly,LSF tended to occur frequently in 2011- 2016. Compared to days with sub-zero temperature during possible LSF in 2011- 2013,that in 2014- 2016 tended to decline. Trees from the genera for many ornamental trees in Beijing had been recorded to suffer LSF,which had less impact on evergreen species than on deciduous species in past records. [Conclusion]It is suggested to use more evergreen trees than deciduous trees for the construction of urban greening in Beijing to cope with more possible LSFs in future.