Ecological Archives E087-078-A4

Jarrod M. Thaxton and William J. Platt. 2006. Small-scale fuel variation alters fire intensity and shrub abundance in a pine savanna. Ecology 87:1331–1337.

Appendix D. One figure and four ANOVA tables for damage to shrub leaves and stems during fires.

 

   FIG. D1. Effects of fuel treatments on probability of damage to shrub leaves during fires in 1999 and 2001. Overall bar height indicates mean probability of visible damage (>10% of leaves consumed); shaded or patterned area indicates probability that observed damage was complete (>90% consumed). Values are least-square means + SE of probabilities, back-transformed from logits.

 

TABLE D1. Results of generalized linear mixed-model analysis of probability of visible damage to shrub leaves.

Source of variation
df†
F
P
Fixed Effects:
 
 
 
Elevation
1, 10.1
7.36
0.02
Fuel
3, 594
30.69
<0.001
Elevation × Fuel
3, 596
1.63
0.182
Year
1, 684
0.24
0.645
Elevation × Year
1, 684
3.09
0.079
Fuel × Year
3, 686
12.46
<0.001
Elevation × Fuel × Year
3, 686
1.35
0.259
 
 
 
 
Linear Contrasts (Fuel):
 
 
 
(Controls + Fuel Removal) vs. (Pine Needle Addition + Wood Addition)
1, 625
22.76
<0.001
Controls vs. Fuel Removal
1, 520
51.35
<0.001
Pine Needle Addition vs. Wood Addition
1, 674
0.84
0.36
 
 
 
 
Linear Contrasts (Fuel by Year):
 
 
 
[(Controls + Fuel Removal) vs.
(Pine Needle Addition + Wood Addition)] × (Post-fire 1 vs. Post-fire 2)
1, 684
7.11
0.008
[(Controls vs. Fuel Removal) × (Post-fire 1 vs. Post-fire 2)
1, 691
22.02
<0.001
(Pine Needle Addition vs. Wood Addition) × (Post-fire 1 vs. Post-fire2)
1, 681
0.32
0.57

   Notes: Error term for Elevation = Elevation × Transect (Ravine). Error term for Fuel and interactions = Quadrat (Fuel × Elevation × Transect (Ravine)). Error term for Year and interactions = residual.

† Denominator degrees of freedom based on Satterthwaite approximation. Significance level is P < 0.025.

 

TABLE D2. Results of generalized linear mixed-model analysis of probability of complete damage to shrub leaves.

Source of variation
df†
F
P
Fixed Effects:
 
 
 
Elevation
1, 9.25
5.98
0.037
Fuel
3, 516
33.42
<0.001
Elevation × Fuel
3, 512
1.17
0.32
Year
1, 483
14.93
0.001
Elevation × Year
1, 484
2.92
0.088
Fuel × Year
3, 496
3.09
0.027
Elevation × Fuel × Year
3, 496
6.54
0.002
 
 
 
 
Linear Contrasts (Fuel):
 
 
 
(Controls + Fuel Removal) vs. (Pine Needle Addition + Wood Addition)
1, 555
62.25
<0.001
Controls vs. Fuel Removal
1, 397
29.22
<0.001
Pine Needle Addition vs. Wood Addition
1, 626
1.46
<0.001
 
 
 
 
Linear Contrasts (Fuel by Year):
 
 
 
[(Controls + Fuel Removal) vs.
(Pine Needle Addition + Wood Addition)] × (Post-fire 1 vs. Post-fire 2)
1, 484
0.47
0.44
[(Controls vs. Fuel Removal) × (Post-fire 1 vs. Post-fire 2)
1, 550
8.94
0.99
(Pine Needle Addition vs. Wood Addition) × (Post-fire 1 vs. Post-fire2)
1, 461
0.05
0.02

   Notes: Error term for Elevation = Elevation × Transect (Ravine). Error term for Fuel and interactions = Quadrat (Fuel × Elevation × Transect (Ravine)). Error term for Year and interactions = residual.

† Denominator degrees of freedom based on Satterthwaite approximation. Significance level is P < 0.025.

 

TABLE D3. Results of generalized linear mixed-model analysis of probability of visible damage to shrub stems.

Source of variation
df†
F
P
Fixed Effects:
 
 
 
Elevation
1, 13
9.16
0.01
Fuel
3, 526
106.7
<0.001
Elevation × Fuel
3, 524
0.85
0.469
Year
1, 625
13.38
<0.001
Elevation × Year
1, 625
1.33
0.25
Fuel × Year
3, 625
0.39
0.76
Elevation × Fuel × Year
3, 626
0.26
0.86
 
 
 
 
Linear Contrasts (Fuel):
 
 
 
(Controls + Fuel Removal) vs. (Pine Needle Addition + Wood Addition)
1, 496
192.37
<0.001
Controls vs. Fuel Removal
1, 496
124.73
<0.001
Pine Needle Addition vs. Wood Addition
1, 496
18.28
<0.001
 
 
 
 
Linear Contrasts (Fuel by Year):
 
 
 
[(Controls + Fuel Removal) vs.
(Pine Needle Addition + Wood Addition)] × (Post-fire 1 vs. Post-fire 2)
1, 516
0.6
0.44
[(Controls vs. Fuel Removal) × (Post-fire 1 vs. Post-fire 2)
1, 516
0.001
0.99
(Pine Needle Addition vs. Wood Addition) × (Post-fire 1 vs. Post-fire2)
1, 516
5.11
0.02

   Notes: Error term for Elevation = Elevation × Transect (Ravine). Error term for Fuel and interactions = Quadrat (Fuel × Elevation × Transect (Ravine)). Error term for Year and interactions = residual.

† Denominator degrees of freedom based on Satterthwaite approximation. Significance level is P < 0.025.

 

TABLE D4. Results of generalized linear mixed-model analysis of probability of complete damage to shrub stems.

Source of variation
df†
F
P
Fixed Effects:
 
 
 
Elevation
1, 12.5
4.71
0.06
Fuel
3, 412
19.9
<0.001
Elevation × Fuel
3, 408
0.55
0.65
Year
1, 490
0.17
0.68
Elevation × Year
1, 487
0.03
0.86
Fuel × Year
3, 392
4.36
0.01
Elevation × Fuel × Year
3, 391
0.18
0.91
 
 
 
 
Linear Contrasts (Fuel):
 
 
 
(Controls + Fuel Removal) vs. (Pine Needle Addition + Wood Addition)
1, 362
50.61
<0.001
Controls vs. Fuel Removal
1, 362
1.98
0.16
Pine Needle Addition vs. Wood Addition
1, 362
0.45
0.5
 
 
 
 
Linear Contrasts (Fuel × Year):
 
 
 
[(Controls + Fuel Removal) vs.
(Pine Needle Addition + Wood Addition)] × (Post-fire 1 vs. Post-fire 2)
1, 232
7.84
0.01
[(Controls vs. Fuel Removal) × (Post-fire 1 vs. Post-fire 2)
1, 232
0.1
0.75
(Pine Needle Addition vs. Wood Addition) × (Post-fire 1 vs. Post-fire2)
1, 232
8.21
0.005

   Notes: Error term for Elevation = Elevation × Transect (Ravine). Error term for Fuel and interactions = Quadrat (Fuel × Elevation × Transect (Ravine)). Error term for Year and interactions = residual.

† Denominator degrees of freedom based on Satterthwaite approximation. Significance level is P < 0.025.


[Back to E087-078]