Ecological Archives E095-166-A4

Guadalupe Peralta, Carol M. Frost, Tatyana A. Rand, Raphael K. Didham, and Jason M. Tylianakis. 2014. Complementarity and redundancy of interactions enhance attack rates and spatial stability in host–parasitoid food webs. Ecology 95:1888–1896. http://dx.doi.org/10.1890/13-1569.1

Appendix D. Coefficients for best-fitting model without covariate removal.

Table D1. Coefficients for best-fitting generalized linear mixed-effects models testing the effect of community and food-web metrics on (A) cumulative parasitism rates (with binomial error, Z test); (B) temporal variability of parasitism rates, measured as the coefficient of variation of parasitism rates through time (with Gaussian error, t value, P values estimated by Markov Chain Monte Carlo procedure); (C) spatial variability of parasitism rates, measured as the coefficient of variation of parasitism rates through space (with Gaussian error, t test). Host and parasitoid species richness, and connectance (the weighted number of realized links) were entered as covariates, and their removal was not allowed during model selection procedure. Bold values indicate significant results (α = 0.05).

Response variable

Fixed effects

Estimate ± SE

Z/t value

P value/PMCMC

A) Parasitism rates

Intercept

-4.354 ± 0.925

-4.704

> 0.001

 

Host richness

0.014 ± 0.027

0.527

0.598

 

Parasitoid richness

0.069 ± 0.021

3.305

> 0.001

 

Connectance

3.039 ± 2.610

1.164

0.244

 

Parasitoid standardized functional complementarity

1.109 ± 0.474

2.339

0.019

B) Temporal variability of parasitism rates

Intercept

-0.082 ± 0.651

     -0.13

0.631

 

Host richness

-0.011 ± 0.030

-0.37

0.806

 

Parasitoid richness

-0.040 ± 0.024

-1.67

0.597

 

Connectance

1.611 ± 1.755

0.92

0.352

C) Spatial variability of parasitism rates

Intercept

-0.239 ± 0.487

-0.49

0.657

 

Host richness

0.007 ± 0.008

0.84

0.461

 

Parasitoid richness

0.007 ± 0.008

0.98

0.399

 

Connectance

3.566 ± 2.767

1.29

0.288

 

Parasitoid functional redundancy

-0.065 ± 0.029

-2.27

0.108


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