Table A3.1.
Results of the linear mixed-effects models (LMMs) carried out on the effects of fertilization and irrigation on plant species richness, vegetation structure, hay production, arthropod abundance and biomass. Table refers to Fig. 2 in the article. The fixed factors were the experimental treatments (with four levels: C = control plots; F = fertilized; I = irrigated; I + F = irrigation and fertilization combined) and the sampling sessions (two levels: July and August). Random factor were the experimental study sites. P-values and 95% confidence intervals (CI) were computed with 100,000 Markov chain Monte Carlo (MCMC) iterations. MCMC mean parameter estimates (differences between expected mean densities) are given for the paired treatments comparisons, and significant contrasts are highlighted in bold
| Response variable and comparison | MCMC mean | Lower 95% CI | Upper 95% CI | MCMC P-value |
|---|---|---|---|---|
| Plant species richness (log scale) | ||||
| F vs. C | 0.109 | 0.016 | 0.205 | 0.023 |
| I vs. C | 0.240 | 0.145 | 0.333 | <0.001 |
| I + F vs. C | 0.236 | 0.144 | 0.331 | <0.001 |
| I vs. F | 0.130 | 0.035 | 0.223 | 0.007 |
| I + F vs. F | 0.127 | 0.033 | 0.221 | 0.009 |
| I + F vs. I | −0.003 | −0.097 | 0.092 | 0.947 |
| Structure of vegetation (index) | ||||
| F vs. C | 0.136 | −0.001 | 0.272 | 0.051 |
| I vs. C | 0.311 | 0.176 | 0.450 | <0.001 |
| I + F vs. C | 0.392 | 0.255 | 0.529 | <0.001 |
| I vs. F | 0.175 | 0.039 | 0.311 | 0.012 |
| I + F vs. F | 0.256 | 0.121 | 0.395 | 0.001 |
| I + F vs. I | 0.081 | −0.054 | 0.219 | 0.247 |
| Hay production [g·m−2] | ||||
| F vs. C | 226.8 | 101.1 | 352.5 | 0.001 |
| I vs. C | 384.4 | 262.6 | 514.1 | <0.001 |
| I + F vs. C | 503.2 | 379.7 | 630.8 | <0.001 |
| I vs. F | 157.6 | 29.0 | 280.2 | 0.015 |
| I + F vs. F | 276.7 | 150.2 | 400.7 | <0.001 |
| I + F vs. I | 118.8 | −7.2 | 245.6 | 0.065 |
| Arthropod abundance (log scale) | ||||
| F vs. C | 0.403 | −0.039 | 0.845 | 0.072 |
| I vs. C | 0.935 | 0.497 | 1.378 | <0.001 |
| I + F vs. C | 1.014 | 0.579 | 1.452 | <0.001 |
| I vs. F | 0.534 | 0.087 | 0.966 | 0.018 |
| I + F vs. F | 0.612 | 0.164 | 1.044 | 0.006 |
| I + F vs. I | 0.077 | −0.365 | 0.514 | 0.730 |
| Arthropod biomass [g] (log scale) | ||||
| F vs. C | 0.829 | 0.327 | 1.303 | 0.001 |
| I vs. C | 0.824 | 0.325 | 1.306 | 0.001 |
| I + F vs. C | 0.734 | 0.237 | 1.219 | 0.004 |
| I vs. F | −0.005 | −0.501 | 0.477 | 0.983 |
| I + F vs. F | −0.094 | −0.579 | 0.397 | 0.706 |
| I + F vs. I | −0.091 | −0.587 | 0.389 | 0.716 |