Branch initiation and mortality
Over the period studied (1929-2013) branch initiation frequency was
negatively correlated with mean summer temperatures in the year prior to
branch initiation (r=-0.23, p<0.05; Fig. 3c), i.e. warm
summers were linked with a lower amount of new branches formed in the
year after. Over the period 1987-2013, branch mortality frequency was
positively correlated with mean early winter temperatures following the
growing season in the year of death (r=0.59, p<0.002; Fig. 3d)
and with mean temperatures in spring prior to the growing season (0.50,
p<0.01). Higher temperatures before and after the growing
season were thus related with higher branch mortality.