Authors: Reeves, Laura; Garratt, Michael;Fountain, Michelle;Senapathi, Deepa;

Climatic warming has shifted flowering times in multiple plant species. Changes in flowering phenology could have significant implications for ecosystems; impacting pollination services, pest populations and community interactions. Furthermore, there is lack of information on how crop flowering times will react to future climate scenarios. Using 60 years of data from pear (Pyrus communis L.) orchards in Kent, UK we explored temporal changes in flowering phenology, identified weather variables driving this change, and predicted how flowering times may be altered with respect to future emissions scenarios. We show pear flowering (1990-2020) in the last 30 years has advanced 11.44 days compared to historical data (1960-1989). Moreover, this shift is apparent in all twelve pear cultivars and four phenological stages analysed. Our results indicate this advancement began after 1982; that air temperature and frost days significantly impact flowering; and this change in phenology is likely to continue under future climate scenarios. Four Representative Concentration Pathways from the UK Climate Projections 2018 report were used to model future climate impacts, under all scenarios a phenological advancement in flowering time was predicted by 2080. Methods used could be easily applied to other plant species, making broader predictions about the impact of climate change.