Appendix D. Results of after-only gradient analysis at the Cerro Grande Fire, New Mexico, USA.
TABLE D1. Results of repeated-measures GLM testing the effects of burn severity rank and cover type on bird species densities (log transformed) the first two years post-fire (after-only) at the Cerro Grande Fire, New Mexico. Average densities were estimated by plot (n = 49) and stratified by cover type, and year. Significant effects (P < 0.10) are bolded. Burn severity was retained in the final model; covariates and nonlinear effects of burn severity were dropped from the model when P > 0.10 (indicated by dashed lines).
Burn Severity |
Cover Type‡ |
Year (2001, 2002) |
Burn Severity2 |
|||||||||
Species† |
F |
df |
P |
F |
df |
P |
F |
df |
P |
F |
df |
P |
Mourning Dove |
3.74 |
1, 47 |
0.059 |
-- |
-- |
-- |
33.36 |
1, 48 |
<0.001 |
-- |
-- |
-- |
Broad-tailed Hummingbird |
9.47 |
1, 47 |
0.004 |
-- |
-- |
-- |
20.22 |
1, 48 |
<0.001 |
-- |
-- |
-- |
Hairy Woodpecker |
5.78 |
1, 47 |
0.020 |
-- |
-- |
-- |
27.59 |
1, 48 |
<0.001 |
-- |
-- |
-- |
Northern Flicker§ |
0.05 |
1, 47 |
0.823 |
-- |
-- |
-- |
0.017 |
1, 47 |
0.684 |
-- |
-- |
-- |
Western Wood-pewee |
46.33 |
1, 48 |
<0.001 |
-- |
-- |
-- |
2.29 |
1, 48 |
0.137 |
-- |
-- |
-- |
Cordilleran Flycatcher |
11.88 |
1, 46 |
0.001 |
3.36 |
1,46 |
0.073 |
0.02 |
1, 48 |
0.900 |
-- |
-- |
-- |
Warbling Vireo |
35.64 |
1, 46 |
<0.001 |
5.47 |
1,46 |
0.024 |
10.66 |
1, 48 |
0.002 |
-- |
-- |
-- |
Steller’s Jay |
5.04 |
1, 46 |
0.030 |
-- |
-- |
-- |
0.01 |
1, 46 |
0.910 |
7.94 |
1,46 |
0.007 |
Mountain Chickadee |
43.41 |
1, 47 |
<0.001 |
-- |
-- |
-- |
1.70 |
1, 48 |
0.199 |
-- |
-- |
-- |
White-breasted Nuthatch |
0.15 |
1, 46 |
0.700 |
4.89 |
1,46 |
0.032 |
10.43 |
1, 48 |
0.002 |
-- |
-- |
-- |
House Wren|| |
14.52 |
1, 46 |
<0.001 |
32.25 |
1,46 |
<0.001 |
3.12 |
1, 47 |
0.084 |
-- |
-- |
-- |
Western Bluebird § |
68.04 |
1, 47 |
<0.001 |
-- |
-- |
-- |
0.290 |
1, 47 |
0.591 |
-- |
-- |
-- |
Hermit Thrush |
97.28 |
1, 47 |
<0.001 |
-- |
-- |
-- |
0.47 |
1, 48 |
0.498 |
-- |
-- |
-- |
American Robin |
2.88 |
1, 47 |
0.096 |
-- |
-- |
-- |
4.15 |
1, 48 |
0.047 |
-- |
-- |
-- |
Virginia’s Warbler|| |
5.01 |
1, 47 |
0.030 |
-- |
-- |
-- |
5.85 |
1, 46 |
0.020 |
10.63 |
1,46 |
0.002 |
Yellow-rumped Warbler |
49.80 |
1, 47 |
<0.001 |
-- |
-- |
-- |
2.82 |
1, 48 |
0.100 |
-- |
-- |
-- |
Western Tanager |
1.39 |
1, 46 |
0.244 |
-- |
-- |
-- |
17.78 |
1, 46 |
<0.001 |
-- |
-- |
-- |
Spotted Towhee§,¶ |
2.79 |
1, 46 |
0.100 |
-- |
-- |
-- |
1.29 |
1, 46 |
0.26 |
3.24 |
1,46 |
0.078 |
Chipping Sparrow |
4.81 |
1, 46 |
0.033 |
-- |
-- |
-- |
16.69 |
1, 48 |
<0.001 |
-- |
-- |
-- |
Dark-eyed Junco |
27.28 |
1, 47 |
<0.001 |
-- |
-- |
-- |
1.26 |
1, 48 |
0.267 |
-- |
-- |
-- |
Black-headed Grosbeak |
5.43 |
1, 45 |
0.020 |
9.00 |
1,45 |
0.004 |
1.95 |
1, 45 |
0.169 |
6.08 |
1,45 |
0.020 |
† See Appendix C for scientific names.
‡ Cover types: ponderosa pine, mixed conifer forest. Burn severity × cover type was not significant for any species.
§ Burn severity × year was significant for Northern Flicker (F 1, 47 = 3.09, P = 0.085), Spotted Towhee (F 1, 46 = 6.41, P = 0.015) and Western Bluebird (F 1, 47 = 11.92, P = 0.001).
|| Cover type × year was significant for House Wren (F 1, 47 = 7.95, P = 0.007) and Virginia’s Warbler (F 1, 46 = 3.76, P = 0.06).
¶ Burn severity2 × year was significant for Spotted Towhee ( F 1, 46 = 4.75, P = 0.03).