Table 1.

Summary statistics and model comparisons using Δ AIC (difference in Akaike Information Criterion from best model). Models within 2 units of the best are underlined

Speciesa	Number of years	Mean day of event [ordinal date]	Standard deviation	Δ AIC
				Null	UniForc	UniChill 1 Sept	UniChill 1 Nov	Time window	Double time window	PSR
hawthorn – Crataegus monogyna	143	9 March [67.6]	19.1	119.4	23.7	0.0	25.4	32.5	17.9	15.9
wood anemone – Anemone nemorosa	140	25 March [83.8]	13.0	100.3	11.4	2.1	0.1	9.4	6.2	0.0
sycamore – Acer pseudoplantanus	134	1 April [91.0]	13.3	66.2	7.4	1.9	12.3	8.6	0.0	8.2
horse chestnut – Aesculus hippocastanum	142	4 April [93.8]	10.4	94.7	6.6	0.0	6.5	7.4	0.3	12.7
elm – Ulmus (procera?)	118	5 April [95.3]	14.9	41.8	0.0	0.4	0.3	4.0	4.3	8.4
birch – Betula (pendula?)	140	6 April [95.6]	12.9	88.3	18.1	0.0	19.4	22.4	3.8	8.5
rowan – Sorbus acuparia	138	6 April [96.0]	11.4	153.2	25.0	0.0	15.1	42.3	17.4	17.3
hornbeam – Carpinus betulus	137	7 April [97.5]	15.2	48.5	7.3	0.0	3.9	9.2	8.6	7.5
lime – Tilia spp.	140	13 April [102.7]	11.6	125.2	10.7	0.0	3.5	24.6	10.5	13.6
maple – Acer (campestre?)	96	19 April [108.5]	13.4	38.6	13.8	7.1	14.3	11.4	0.0	7.8
sweet chestnut – Castanea sativa	134	19 April [108.6]	11.3	111.1	1.1	0.0	5.1	19.4	12.6	16.1
beech – Fagus sylvatica	143	20 April [110.0]	7.8	92.5	0.0	1.0	4.5	10.9	12.0	15.8
oak – Quercus spp.	141	23 April [113.1]	10.7	197.9	19.4	2.6	0.0	58.8	42.5	31.8
ash – Fraxinus excelsior	129	29 April [118.7]	11.1	53.4	0.0	4.4	0.9	9.1	9.4	15.2

^aSpecies identities follow Sparks & Carey (1995). Latin binomials in parentheses indicate records for which the species is uncertain.