Ammonia-oxidizing archaea and bacteria are structured by geography in biological soil crusts across North American arid lands

Ecological Processes

Table 3 Results from correlation and multiple linear regression analyses for microbial communities in biological soil crusts

	Bivariate correlation (Pearson r coefficients)				Regression (p values)
Independent variable	Archaeal *amoA (* n = 39)	Bacterial *amoA* ( n = 38)	Archaeal to bacterial *amoA* ( n = 33)	Archaeal *amoA* to 16S ( n = 28)	Archaeal *amoA* vs. bacterial *amoA*
Latitude	−0.53^**	0.40^*	−0.70^**	−0.55^**	<0.001
Elevation	−0.22	0.78^**	−0.61^**	−0.25	<0.001
MAP	−0.13	0.67^**	−0.48^**	−0.12	0.004
MAT	0.39^*	−0.65^**	0.69^**	0.40^*	<0.001

**Correlation is significant at the 0.01 level. *Correlation is significant at the 0.05 level. MAP, mean annual precipitation; MAP, mean annual temperature.