Effects of climate warming on timing of lime (Tilia cordata L.) phenology

Abstract

This study is aimed to investigate impact of climate warming on timing of lime phenological spring (bud burst and leaf unfolding) and phenological autumn (leaf colouring and fall). An essential shift in timing of all investigated phenological phases is detected. The most significant advancing was detected in the case of earliest phenological phase. Shift of bud burst dates during investigated period (1956-2010) consisted 13.5 days. Shift in timing of leaf unfolding was detected to be not so essential and consisted 9.7 days during the same period. The leaf colouring of lime has been delayed by 10 days and leaf fall approximately by 12 days during the study period. As a consequence of observed changes in spring and autumn phenology, growing season of lime has been extended by 22.6 days during 1956 -2010 period. Occurrence of lime leaf unfolding is best correlated with late winter (January, February) and early spring (March) temperature, i.e. with temperature of most warmed during last decade’s months. Relationship of leaf colouring and fall timing with temperature is much weaker and in most cases statistically insignificant, indicating that timing of phenological autumn is more complex process and can‘t be explained only by changes in temperature.