Variability in the growing season of selected European and East-Asian woody species in relation to air temperature changes

Abstract

Data series for leaf unfolding and leaf fall phenophases of European and East-Asian trees were
analysed and related to air temperature at the Mlyňany Arboretum SAS. Over a period 1971–2011,
annual mean air temperature (T am ) and mean spring air temperature (T 24 ) increased by 1.41 °C
or 1.06 °C, respectively. The temperature increase affected onset of phenophases and length of
growing season. Beginning of growing season (BGS) advanced by 19 days for European (1990–
2011) and 9 days for Asian taxa (1991–2008). End of growing season (EGS) delayed by 2 or 4
days for European and Asian species, respectively. Length of growing season (LGS) extended
by 10.31 or 7.58 day / decade for European and Asian species, respectively. The earlier onset of
BGS was more prominent for European than Asian taxa and the difference was significant. On the
other hand, a difference in EGS or LGS between European and Asian species was not significant.
Relationships between BGS and T am or T 24 were significant for all species, and the relationships
were closer for European species. Strong and significant correlation was detected between T am and
LGS of European trees, however it was weak and non-significant for Asian species.