Table 1.

F-values from a Three-Way ANOVA comparing the abundance of different bacterial phyla in response to nitrogen(N) addition, soil depth, and microhabitat.

	N	N response	Soil depth	Depth response	Microhabitat	Micro- response
Acidobacteria§	13.7***	↑	6.0 **	L	65.5***	I
Actinobacteria	10.1***	↓	57.2***	L	0.90
Armatimonadetes±	1.14		0.11		46.0***	I
Bacteroidetes±	2.91		73.9***	U	92.3***	C
Chloroflexi	4.59*	↓	55.6***	L	45.8***	I
Firmicutes§	19.0***	↑	0.01		23.2***	I
Planctomycetes	1.52		58.2***	L	15.4***	C
Proteobacteria§	9.62***	↓	18.7***	U	29.4***	C
Verrucomicrobia§	12.1***	↑	6.80*	U	10.2 **	I

Significance levels are represented as

^*p < 0.05,

^**p < 0.01,

^***p < 0.001. Nitrogen response indicates the overall trend of N response (positive or negative). Depth and microhabitat response indicates the factor where the highest abundance was observed, where U indicates upper biocrust soil layer, L indicates lower bulk soil layer, I indicates interspace soils, C indicates shrub canopy soils.

^§Indicates a significant interaction between N and soil depth.

^±Indicates a significant interaction between soil depth and microhabitat.

The arrows correspond to positive or negative responses to nitrogen.