Peter B. Adler, Daniel G. Milchunus, Osvaldo E. Sala, Ingrid C. Burke, and William K. Lauenroth. 2005. Plant traits and ecosystem grazing effects: comparison of U.S. sagebrush steppe and Patagonian steppe. Ecological Applications 15:774–792.

Appendix B. Statistical tables for single-year mixed-effects models. See Notes at end of tables for details.

Dependent variable	Independent variables	Num df	Den df	F	P
A) Forage consumption
	region	1	34	11.31	0.002
	ppt	2	34	0.93	0.40
	region × ppt	2	34	1.28	0.29
	distance	2	34	5.63	0.008
	region × distance	2	34	6.39	0.004
	ppt × distance	4	34	2.96	0.036
	region × ppt × distance	4	34	6.47	0.0006
B) Forage utilization
	region	1	47	6.07	0.017
	ppt	2	47	1.78	0.18
	distance	1	47	7.94	0.007
C) Perennial grass basal cover
	region	1	16.5	7.76	0.013
	ppt	2	12.5	0.80	0.47
	region × ppt	2	12.1	5.86	0.017
	distance	3	74.4	18.29	<0.0001
	region × distance	3	74.2	0.24	0.87
	ppt × distance	5	73	3.28	0.010
	region × ppt × distance	4	72.6	2.37	0.061
D) Perennial grass above-ground production (log transformed)
	region	1	13	2.45	0.14
	ppt	2	12.1	4.74	0.030
	region × ppt	2	12.2	15.87	<0.001
	distance	3	34.7	10.55	<0.0001
	region × distance	3	34.6	1.91	0.15
	ppt × distance	5	33.3	1.01	0.42
	region × ppt × distance	4	33.1	2.64	0.051
E) Shrub canopy cover (square root transformed)
	region	1	11.4	7.14	0.021
	ppt	2	11.3	3.93	0.051
	region × ppt	2	11.3	9.51	0.004
	distance	3	85.4	4.86	0.004
F) Shrub aboveground production (log transformed)
	region	1	52	33.08	<0.0001
	ppt	2	52	1.95	0.15
	region × ppt	2	52	12.27	<0.0001
	distance	3	52	1.33	0.27
G) Forb aboveground production (log transformed)
	region	1	16.1	1.73	0.21
	ppt	2	12.2	8.19	0.006
	region × ppt	2	11.9	11.86	0.002
	distance	3	31.4	2.40	0.087
	region × distance	3	30.5	8.28	<0.001
	ppt × distance	5	30.2	2.16	0.085
	region × ppt × distance	4	30.9	2.95	0.036
	radiation	1	34.1	6.37	0.016
H) Total aboveground production
	region	1	18.3	0.99	0.33
	ppt	2	12.4	12.58	0.001
	region × ppt	2	12.4	3.55	0.060
	distance	3	42.6	3.17	0.034
	region × distance	3	42.1	2.84	0.049
	radiation	1	36.8	3.92	0.055
I) Mean species richness per 1-m2 quadrat
	region	1	13.9	0.00	0.97
	ppt	2	13.8	36.17	<0.0001
	distance	3	82.7	2.24	0.089
J) Species richness per site (sum across 24 1-m2 quadrats)
	region	1	12.5	15.70	0.002
	ppt	2	12.4	70.80	<0.0001
	region × ppt	2	12.4	5.97	0.015
	distance	3	85.8	0.67	0.58
K) Non-native species richness per site  (sum across 24 1-m2 quadrats)
	region	1	11.5	10.01	0.009
	ppt	2	11.5	25.83	<0.0001
	region × ppt	2	11.4	7.20	<0.001
	distance	3	83.8	6.83	<0.001
L) Soil C (log transformed)
	region	1	49.9	4.52	0.038
	ppt	2	12.2	45.12	<0.0001
	region × ppt	2	11.9	4.77	0.030
	sand	1	52.3	9.90	<0.003
M) Soil N (log transformed)
	region	1	49.9	2.88	0.100
	ppt	2	12.8	41.11	<0.0001
	region × ppt	2	12.4	5.10	0.024
	sand	1	53.9	13.28	<0.001

   Notes: “Region” refers to sagebrush vs. Patagonian steppe, “ppt” refers to arid, intermediate, and semiarid study areas within each region, “distance” is the distance-from-water class, and “radiation” is potential radiation based on slope and aspect. Nonsignificant higher order interactions and covariates (radiation, sand content) were removed when not significant at = 0.10. Nonsignificant main effects (region, ppt, distance) were not removed, except in analyses of soil C and N.