Ecological Archives E096-067-A3

Melissa Whitman and James D. Ackerman. 2015. Terrestrial orchids in a tropical forest: best sites for abundance differ from those for reproduction. Ecology 96:693704. http://dx.doi.org/10.1890/14-0104.1

Appendix C. Top Models per Suite (Generalized Additive Models, Generalized Linear Models, Linear Models).

All tables include the four highest ranked models per model suite. Generalized Linear Model (GLM) and Linear Model (LM) results (Appendix C: Table C2 and C3) also include a fifth model, being the 'equivalent' top model from the other suite (also refer to Appendix A: Fig. A1). The 'top model' selected per suite (shown as '*') was based on a combination of the following: low Akaike's Information Criterion (AIC) and Bayesian Information Criterion (BIC) scores, model weights (while checking for over-fitting of data), and constancy of predictor variables included in highly ranked AIC and BIC models. When two models had similar delta values, we favored the one with the fewer parameters.

Table C1. Top Generalized Additive Models (GAM) for P. stachyodes presence and absence

 

AIC rank

AIC

k

Delta

Weights

Model

 

1

502.99

37

0.00

0.34

s(X, Y) + RADI + INDI + TOPO

*

2

504.69

35

1.70

0.15

s(X, Y) + RADI + INDI

 

3

504.80

40

1.81

0.14

s(X, Y) + RADI + INDI + (SLPE x TOPO)

 

4

505.54

36

2.55

0.10

s(X, Y) + RADI + INDI + SOIL

 

BIC rank

BIC

k

Delta

Weights

Model

 

1

667.00

31

0.00

0.36

s(X, Y) + 1

 

2

667.63

32

0.63

0.26

s(X, Y) + RADI

 

3

669.61

34

2.61

0.10

s(X, Y) + INDI

*

4

671.09

35

4.09

0.05

s(X, Y) + RADI + INDI

Table C2. Top Generalized Linear Models (GLM) for P. stachyodes abundance

 

AIC rank

AIC

k

delta

weights

Model

 

1

286.14

15

0.00

0.99

Global Model ǂ

 

2

301.09

6

14.94

< 0.01

SLPE + WULL + SOIL + RADI

*

3

304.13

5

17.98

< 0.01

SLPE + WULL + SOIL

 

4

317.90

4

31.76

< 0.01

SLPE + SOIL

 

11

337.25

3

51.10

< 0.01

ROCK (predictor from Top LM)

 

BIC rank

BIC

k

delta

weights

Model

 

1

313.12

6

0.00

0.57

SLPE + WULL + SOIL + RADI

*

2

313.75

5

0.63

0.41

SLPE + WULL + SOIL

 

3

319.84

15

6.72

0.02

Global Model ǂ

 

4

325.12

4

12.00

< 0.01

SLPE + SOIL

 

10

342.06

3

28.94

< 0.01

ROCK (predictor from Top LM)

Table C3. Top Linear Models (LM) for P. stachyodes leaf size

 

AIC rank

AIC

k

delta

weights

Model

 

1

794.06

4

0.00

0.35

ROCK + SOIL

 

2

794.83

4

0.78

0.24

ROCK + SLPE

 

3

796.38

4

2.32

0.11

ROCK + WULL

*

4

796.43

3

2.38

0.11

ROCK

 

11

802.24

5

8.18

< 0.01

SLPE + WULL + SOIL (predictors from Top GLM)

 

BIC rank

BIC

k

delta

weights

Model

*

1

803.65

3

0.00

0.27

ROCK

 

2

803.68

4

0.03

0.27

ROCK + SOIL

 

3

804.46

4

0.81

0.18

ROCK + SLPE

 

4

805.62

3

1.96

0.10

CNPY

 

16

814.27

5

10.62

< 0.01

SLPE + WULL + SOIL (predictors from Top GLM)

Model codes: CNPY = canopy class; INDI = Indicator Species category; RADI = residuals from solar radiation α slope ; ROCK = rockiness category; s = smoothing function; SLPE = degree slope; SOIL = soil type; TOPO = topographic position; X = x coordinate, Y = y coordinate, WULL = Wullschlaegelia calcarata presence,

* = Top Model per Suite., ǂ = Global Model for GLM/LM suites :  SLPE + RADI + CNPY + SOIL + ROCK + TOPO + INDI + WULL + X + Y


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