Plant phenology and climate change : possible effect on the onset of various wild plant species first flowering day in the UK

The IPCC states that the planet is significantly warming due to effects of climate change. This warming effect has consequences for phenological events. Many species cannot track rapid climate change, resulting in phenological mismatches. This study looks at an extreme weather event and the longer-term effects of climate change. According to the IPCC, extreme weather is linked to climate change. The study utilises geographical information science (GIS) tools to present the results of the possible relationship between climate change and the first flowering day (FFD) of the 5 species of wild plants. The results show that the UK has significantly warmed by up to 1°C during the period 1984 – 2017 compared to 1950 – 1983, confirming various IPCC reports in the literature that the GMST is warming. Various studies report that the winter of 2007 reflects an extreme weather event, where the winter was significantly warm. Regarding the short-term extreme weather events and their effects on FFD, the UK winter temperatures of 2006 were compared against the winter of 2007. The results showed that the winter mean daily temperatures in 2007 were significantly greater by about 2°C compared to 2006 (p<0.05), where the 2006 winter temperatures were similar to the 1961 – 1990 baseline average, confirming studies in the literature that 2007 experienced an extremely warm winter. The FFD of each species was compared between 2006 and 2007. The results showed that the mean FFD of all species significantly advanced between 13 and 18 days (p<0.05) during the extreme warmer winter of 2007 compared to the cooler (average) 2006 winter, confirming that FFD is affected by temperature. Regarding the longer-term climate change effects on FFD, this study looked at the spatial distribution of FFD based on simple linear regression using temporal data of time series with at least 15-years of FFD records at the same location. This provided a measure of the FFD response to temperature, with the notion that the strongest negative responses are linked to the warmest regions. The results from a total of 351 simple linear regressions showed that 74.6% were significant negative response rates (p<0.05) (FFD advancement - ranging from -3.5 to -6.7 days °C-1), 1.7% were non-significant positive response rates (p≥0.05), the rest were non-significant negative response rates (p≥0.05). Spearman rank correlations were conducted on the 74.6% of significant negative response rates in relation to latitude, longitude and elevation to determine if there was a spatial element that influenced the FFD temperature response rates. There was only one positive significant correlation and this was in respect of coltsfoot (p