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Table 10 Statistical comparison of AUCs (area under the receiver operating characteristic [ROC] curve) between samples burned in one fire and those burned by a second fire. We tested for statistical differences in AUCs between first and second fires using the method of DeLong et al. (1988) as modified for the pROC package in the statistical program R to test unpaired ROC curves (Robin et al. 2011). U = generalized U-statistic; R-A = Ryan and Amman model, which can be applied to many species; Pre-fire models predict morality after fire based on predictors available before fire. Data used to evaluate post-fire tree mortality models are from the USA, from fires occurring from 1981 to 2016

From: A large database supports the use of simple models of post-fire tree mortality for thick-barked conifers, with less support for other species

Model

Burned once

Burned twice

U

df

P

n

AUC

n

AUC

Abies concolor – R-A

11 343

0.894

850

0.862

2.41

937

0.016

Abies concolor – Pre-fire

3 889

0.901

439

0.630

9.62

467

<0.001

Calocedrus decurrens – R-A

2 910

0.972

213

0.861

4.16

217

<0.001

Calocedrus decurrens – Pre-fire

1 405

0.961

170

0.650

6.91

176

<0.001

Pinus lambertiana – R-A

2 286

0.904

99

0.742

2.51

100

0.014

Pinus lambertiana – Pre-fire

857

0.921

72

0.650

3.89

74

<0.001

Pinus ponderosa – R-A

42 133

0.888

1007

0.840

3.18

1036

0.002

Pinus ponderosa – Pre-fire

37 072

0.869

1007

0.783

4.67

1034

<0.001

Pseudotsuga menziesii – R-A

15 101

0.892

75

0.627

4.06

74

<0.001

Pseudotsuga menziesii – Pre-fire

13 528

0.924

75

0.545

5.95

2000

<0.001