Table 1.

Long-term flowering phenology records indicate that the timing of first flowering advanced significantly from 1975 to 2011, and flowering phenology is tightly associated with the timing of snowmelt and temperature. The significance of the random effect (plot) was determined via likelihood ratio tests of models with and without this effect (1 d.f.). Plot was non-significant for the reduced models (p-values were 0.25, 0.12, 0.058, respectively, for separate models of year, snowmelt date and temperature).

	full model				each predictor independently
	β	F1,119	p-value	partial r2	β	F1,121	p-value	r2
year	−0.22 ± 0.05	16.5	<0.0001	0.19	−0.34 ± 0.08	16.6	<0.0001	0.098
snowmelt day	0.32 ± 0.07	19.5	<0.0001	0.23	0.56 ± 0.04	154.6	<0.0001	0.53
temperaturea	−2.95 ± 0.7	18.2	<0.0001	0.22	−5.7 ± 0.45	162.5	<0.0001	0.54
plot		χ2 = 7.5	0.006

^aAverage April and May temperature.