Effects of Climate Warming on Timing of Native and Non-Native Tree Species Phenology

Abstract

The aim of the study was to investigate impact of climate warming on timing of deciduous tree species spring (leaf unfolding) and autumn (leaf falling) phenology and to compare seasonal development and growing season changes of native (Quercus robur L.) and non-native (Quercus rubra L.) tree species. Long-term dataset of phenological observations from Kaunas Botanical Garden of Vytautas Magnus University (central Lithuania) were used for this study. Increased temperature was detected to be a strong driver of spring phenology for both species. It was detected that red oak had a greater response in leaf unfolding 9.5 days comparing with common oak which displayed advance by 8 days during the investigated period. Leaf fall was delayed for common oak by 13.5 days, for red oak -by 1.9 days. An advance of leaf unfolding and delay of leaf fall extended the growing season of investigated tree species. Native tree species responded more than non-native species in response of changes in temperature and the growing season for Q. robur extended by 21.6 days, while for Q. rubra -11.4 days.

Biological Flora of the British Isles:Quercus rubra

“…In Europe, Q. rubra flowers in May (Klotz, Kühn, & Durka, 2002) and acorns are shed from September through October. More detailed observations from Lithuania revealed that leaves of Q. rubra were unfolding in the middle of May (Julian dates 124–134), with leaf fall near the end of October (Julian date 303), according to observations from the years 1980–2013 (Sujetovienė & Šveikauskaitė, 2014). Older observations from the Netherlands (1940–1959) estimate leaf unfolding at the beginning of May (Julian date 123; Kramer, 1994).…”