Date of budburst of fifteen tree species in Britain following climatic warming

摘要: (1) The thermal times (T) (day 'C > 5 since 1 January) to vegetative budburst were measured on fifteen woody perennials in Britain after different durations of chilling (C) (number days < November). (2) Late-flushing species, like Fagus sylvatica, had high values T, even 145 chill days, and T increased greatly with decreased chilling. Early-flushing Crataegus monogyna, small which did not increase much until there fewer than 80-100 days. (3) Relationships the form T= a + b exp (r C) fitted for each then classified into five groups. Past meteorological records used estimate mean dates group species at Edinburgh (26 m altitude) Braemar (339 m) 0-3 uniform climatic warming. (4) Climatic warming markedly shift date any Edinburgh, so they flushed warmer conditions failed exploit earlier springs. However, Braemar, time requirements, C. following