Table 2.

Number of chemical features that increase and decrease in relative abundance by ≥ 75% as a function the dominant stress condition.

Year	Species	Increase by ≥ 75%		Decrease by ≥ 75%
		Stress condition	Number affected	Stress condition	Number affected
2013	Balsam fir	High Temperature	6	High Temperature	21
	Paper birch	High Temperature	28	High Temperature	38
2014	Balsam fir	Drought	43	Temperature + Drought	35
	Paper birch	Drought	98	Temperature + Drought	31
	Red maple	Temperature + Drought	36	Drought	66
	Trembling aspen	Temperature	79	Drought	37
2015	Balsam fir	Temperature + Light	26	Light	111
	Beaked hazel	Temperature + Light	155	Temperature + Light	56
	Paper birch	Temperature + Light	126	Light	278
	Trembling aspen	Temperature + Light	280	Light	162

In most scenarios, the stress condition that led to large-scale increases in relative abundance was different than that which led to large-scale decreases. “Number affected” displays the number of chemical features that either increased or decreased by ≥ 75% for the given species and stress condition.