Table 2.
Models assessing the influence of biotic and abiotic variables on the natural abundance of leaf δ15N (‰) and leaf nitrogen concentration (N, %) for the nine bromeliad morphospecies (n = 5 for all species)
| Fixed effects | Estimate ± s.e. | t-value | d.f. | P | AIC (full model) |
|---|---|---|---|---|---|
| Leaf δ15N | 114·59 (121·24) | ||||
| Intercept | –1·268 ± 0·37 | –3·419 | 41 | 0·0014 | |
| Slope | |||||
| FPOM | 0·563 ± 0·14 | 4·151 | 0·0002 | ||
| PPR | –0·239 ± 0·15 | –1·621 | 0·113 | ||
| Ants | 0·962 ± 0·26 | 3·635 | 0·0008 | ||
| Leaf N | 113·78 (118·7) | ||||
| Intercept | –5·067 ± 1·14 | –4·429 | 40 | <0·0001 | |
| Slope | |||||
| WV | 0·473 ± 0·24 | 1·928 | 0·0614 | ||
| Algae | –0·51 ± 0·18 | –2·826 | 0·0073 | ||
| Ants | 2·371 ± 0·53 | 4·513 | <0·0001 | ||
| Metabolism | 2·024 ± 0·54 | 3·766 | 0·0005 |
Algae, algal abundance; Ant, presence of associated ants; FPOM, fine particulate organic matter (mL); metabolism, C3 vs. CAM photosynthetic pathway; PPR, number of predatory taxa/number of prey taxa; WV, water volume (mL).