Correction

Figures & data

Table 1. Summary of the statistical analyses of the various experimental treatment effects on aboveground biomass among the three point frame years for the six major vascular plant species and lichens and mosses in mesic birch hummock tundra under different experimental manipulations

	GC	G	FC	LN	HN	HP	HNHP	SFC	SF	EC	E
Betula glandulosa
2011 versus 2005
2017 versus 2011	↑*	↑**	↑*		↑**		↑**	↑†		↑*
2017 versus 2005	↑**	↑**	↑*		↑**		↑**	↑†		↑*
Vaccinium uliginosum
2011 versus 2005			↓**		↓**
2017 versus 2011		↑**	↑**		↑**						↑†
2017 versus 2005		↑†				↑†					↑†
Rhododendron subarcticum
2011 versus 2005							↓**	↓**
2017 versus 2011	↑*	↑**	↑**	↑*		↑*		↑**		↑**	↑**
2017 versus 2005	↑*	↑**	↑**				↓**			↑**	↑*
Vaccinium vitis-idaea
2011 versus 2005		↑*			↓**		↓**
2017 versus 2011	↑*	↑**		↑*				↑*		↑*	↑†
2017 versus 2005	↑**	↑**		↑**	↓**		↓**	↑**		↑**	↑**
Andromeda polifolia
2011 versus 2005									↓*
2017 versus 2011	↑**			↑*					↑*
2017 versus 2005	↑*			↑**		↓**					↑†
Eriophorum vaginatum
2011 versus 2005						↑*	↑**		↑*
2017 versus 2011		↑*		↑**
2017 versus 2005	↑**	↑*	↑*	↑**	↑†	↑**	↑**
Lichen
2011 versus 2005		↓**			↓**	↓**	↓**
2017 versus 2011		↓**			↓**		↓**	↑**		↑†	↑†
2017 versus 2005		↓**			↓**	↓**	↓**	↑*	↓†		↑†
Moss
2011 versus 2005		↓**		↓†	↓*		↓*		↑*		↑**
2017 versus 2011	↓**		↓*	↓†	↓*				↓**	↓*	↓**
2017 versus 2005	↓**	↓**	↓**	↓**	↓**		↓*

Notes. GC = control for greenhouse, G = greenhouse, FC = control for fertilization, LN = low-level nitrogen addition, HN = high-level nitrogen addition, HP = high-level phosphorus addition, HNHP = high-level nitrogen + high-level phosphorus addition, SFC = control for snow fence, SF = snow fence, EC = control for exclosure, and E = exclosure. Results are from post hoc tests following repeated measures one-factor (i.e., experimental treatment) ANOVA on the three data years (2005, 2011, and 2017). The upward arrows indicate a positive treatment effect whereas the downward arrows indicate a negative treatment effect and symbols following arrows indicate the significance levels: p .1 (no symbol), †p < .1, *p < .05, **p < .01. See Appendices S4, S7–S9 in the Supporting Information for specific statistical values.