Table 3. Estimates of treatment effects on melt-out dates.

	Melt-out dates			TDD
	Effect ± sd	t-value	p-value	Effect ± sd	t-value	p-value
Intercept (Normal)	155±1.0			272.7±6.7
Removed	−34±0.9	−39.9	<0.001	45.7±11.6	3.95	0.003
Shallow	−5±0.7	−6.9	<0.001	10.7±9.3	1.16	0.253
Medium	8±0.6	14.1	<0.001	−26.4±9.6	−2.74	0.009
Deep	12±0.5	26.2	<0.001	−38.9±9.0	−4.35	<0.001
df	182			6180

Melt-out dates in days of year (doy) and on TDD (thawing degree days, i.e. positive air temperature sums in °C). Effect values other than the intercept (here: Normal treatment) are deviations from the latter. Normal = unmanipulated snow cover; Removed = snow removal on 1. May; Shallow = naturally early snowmelt; Medium = intermediately increased snow; Deep = maximally increased snow. Given are standard deviation (sd), t- and p-values and degrees of freedom (df) of the model.