%0 Research article
%T Regularities and patterns in the spring phenology of some boreal trees
%A Linkosalo, Tapio
%D 1999
%J Silva Fennica
%V 33
%N 4
%R doi:10.14214/sf.647
%U https://silvafennica.fi/article/647
%X Phenological time series of flowering and bud burst of Populus tremula  (L.) and Betula sp., and the flowering of Pinus sylvestris (L.), Alnus  glutinosa (L.) and Alnus incana (L.) were constructed from data  collected in Finland during the period 1896–1955. The resulting combined  time series were examined with two aims in mind: first, to determine  the phenological regularities between different species and, second, to  detect patterns of spring advancement over a geographically large area.  The results indicate that the geographical pattern of spring advancement  is rather uniform from year to year, and between different species.  Furthermore, the mechanisms regulating the timing of phenological events  in different species seem to function in a similar way, suggesting an  unanimous optimal response to climatic conditions.