Ecological Archives E093-167-A5

Claudio de Sassi, Owen T. Lewis, and Jason M. Tylianakis. 2012. Plant-mediated and nonadditive effects of two global change drivers on an insect herbivore community. Ecology 93:1892–1901. http://dx.doi.org/10.1890/11-1839.1

Appendix E. Changes in herbivore abundance and biomass through time in response to temperature and nitrogen addition.

TABLE E1. Results table from a generalized linear mixed effects model (Poisson errors) with the total abundance of larvae as the response. This minimum adequate model was generated by removing nonsignificant parameters from the maximal model (see main text) to provide the best fit (lowest Akaike Information Criterion, AIC score). Each fixed effect was tested here by removing it from the model and testing for a change in unexplained deviance using a likelihood ratio test. Individual coefficients and tests of their significance are shown below. Asterisks indicate level of significance (.≤ 0.1,  * ≤ 0.05, ** ≤ 0.01, *** ≤ 0.001).

 

df

AIC

ΔAIC

Chisq Chi

P

 

Fullmodel

10

818.21

 

 

 

 

3 way interaction

10

858.90

40.69

60.681

<0.0001

***

Temperature × nitrogen

1

859.1

0.20

2.208

0.118

 

Nitrogen × time

10

896.96

38.06

58.067

<0.0001

***

Temperature × time

10

903.48

44.58

64.586

<0.0001

***

Nitrogen

1

914.76

11.28

21.185

0.001

***

Temperature

1

907.01

10.05

7.573

0.022

*

Time

10

1306.34

411.24

386.15

<0.0001

****

 

TABLE E2. Full coefficient table for model of changes in larval abundance through time with Poisson error distribution.

 

Estimate

Std.Error

z value

Pr(>|z|)   

 

(Intercept)

-0.5866

 1.5375

-0.382

0.702824   

 

Temperature

0.3655

0.2845

1.285

0.198943   

 

Nitrogen

-0.7540

1.3551

-0.556

0.577941   

 

time2

-2.3766

1.3007

-1.827

0.067668

time3

-1.1481

1.4485

-0.793

0.428016   

 

time4

-2.7208

1.6542

-1.645

0.100024   

 

time5

2.4634

2.7745

0.888

0.374618   

 

time6

1.2464

3.4771

0.358

0.719999   

 

time7

-3.0267

1.8895

-1.602

0.109195   

 

time8

-5.7385

1.5938

-3.601

0.000318

***

time9

-1.5014

1.3955

-1.076

0.281969   

 

time10

-3.5032

1.4435

-2.427

0.015229

time11

-2.8313

2.7668

-1.023

0.306154   

 

temp:nitrogen

0.1383

0.2467

0.561

0.575070   

 

temp:time2

0.4699

0.2341

2.007

0.044728

temp:time3

0.1650

0.2632

0.627

0.530655   

 

temp:time4

0.3756

0.2968

1.265

0.205701   

 

temp:time5

-0.8499

0.5396

-1.575

0.115282   

 

temp:time6

-0.7111

0.6714

-1.059

0.289539   

 

temp:time7

0.3625

0.3385

1.071

0.284248   

 

temp:time8

0.9474

0.2786

3.401

0.000672

***

temp:time9

0.2557

0.2527

1.012

0.311667    

 

temp:time10

0.6010

0.2574

2.335

0.019523

temp:time11

0.1546

0.5010

0.309

0.757606   

 

Nitrogen:time2

5.2323

1.8227

2.871

0.004096

**

Nitrogen:time3

3.8904

1.9316

2.014

0.044004

Nitrogen:time4

5.9396

2.4505

2.424

0.015359

Nitrogen:time5

-0.1296

3.4769

-0.037

0.970261   

 

Nitrogen:time6

-1.1942

4.2108

-0.284

0.776715   

 

Nitrogen:time7

1.7651

2.4506

0.720

0.471362   

 

Nitrogen:time8

0.9533

2.1377

0.446

0.655643   

 

Nitrogen:time9

4.6734

1.9048

2.453

0.014150

Nitrogen:time10

3.7820

1.8964

1.994

0.046117

Nitrogen:time11

-0.6891

3.1457

-0.219

0.826613   

 

temp:nitrogen:time2

-0.9482

0.3318

-2.858

0.004265

**

temp:nitrogen:time3

-0.6258

0.3530

-1.773

0.076254

temp:nitrogen:time4

-1.1555

0.4533

-2.549

0.010802

temp:nitrogen:time5

0.1595

0.6698

0.238

0.811807   

 

temp:nitrogen:time6

0.3964

0.8024

0.494

0.621338   

 

temp:nitrogen:time7

-0.2214

0.4396

-0.504

0.614484   

 

temp:nitrogen:time8

-0.1139

0.3736

-0.305

0.760451   

 

temp:nitrogen:time9

-0.8084

0.3482

-2.321

0.020262

temp:nitrogen:time10

-0.5706

0.3402

-1.678

0.093439

temp:nitrogen:time11

0.4251

0.5662

0.751

0.452764

 

 

TABLE E3. Results of a linear mixed effects model with Gaussian errors and total herbivore biomass through time as the response. This minimum adequate model was generated by removing non-significant parameters from the maximal model (see main text) to provide the best fit (lowest Akaike Information Criterion, AIC score). Each fixed effect was tested by removing it from the model and testing for a change in unexplained deviance using a likelihood ratio test. Individual coefficients and tests of their significance are shown in below. Asterisks indicate level of significance (.≤ 0.1,  * ≤ 0.05, ** ≤ 0.01, *** ≤ 0.001).

 

df

AIC

ΔAIC

Chisq Chi

P

 

Best model

3

2233.4

 

 

 

 

Temperature

1

2266.3

32.9

21.485

<0.0001

 ***

Nitrogen 

1

2250.6

17.2

5.8103

0.0547

 .

Time   

3

2243.7

10.3

2.8454

0.584

 

Temperature × time

3

2248.8

15.4

21.423

<0.0001

***

 

TABLE E4. Full coefficients table of model for changes in herbivore biomass through time with Gaussian error distribution.

 

Estimate 

Std.Error

t value

pMCMC

 

(Intercept)

-16068.08

4300.71

-3.736

0.001

**

Temp

3594.87

802.60

4.479

0.002

**

nitrogenN

7794.26

5431.11

1.435

0.188

 

time9

6049.21

5300.90

1.141

0.302

 

time10

494.99

5300.90

0.093

0.935

 

time11

12380.58

5300.90

2.336

0.035

*

temp:nitrogenN

1742.91

1017.14

1.714

0.118

 

temp:time9

-1168.03

992.75

-1.177

0.284

 

temp:time10

79.12

992.75

0.080

0.933

 

temp:time11

-2508.84

992.75

-2.527

0.022

*

nitrogenN:time9

7936.48

7496.61

1.059

0.347

 

nitrogenN:time10

8633.13

7496.61

1.152

0.300

 

nitrogenN:time11

9042.91

7496.61

1.206

0.278

 

temp:nitrogenN:time9

-1568.76

1403.96

-1.117  

0.314

 

temp:nitrogenN:time10

-1856.53

1403.96

-1.322   

0.229

 

temp:nitrogenN:time11

-1650.01

1403.96

-1.175

0.288

 


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