Table 1. Comparisons between study sites. Several measures characterizing forest structure, branch abundance, epiphyte abundance and epiphyte richness.
| Brazilian core transects (n = 30) | Brazilian edge transects (n = 30) | Panamanian transects (n = 36) | |||
|---|---|---|---|---|---|
| Variable | No ferns and aroids | All species | |||
| Trees | Mean number per transect | 5.1 ± 2.1 ab | 6.4 ± 3.2 a | ‒ | 4.8 ± 2.1 b |
| Mean DBH (m) | 0.2 ± 0.1 a | 0.18 ± 0.06 b | ‒ | 0.16 ± 0.06 b† | |
| Mean height at first branching (m) | 8.2 ± 2.0 a | 4.7 ± 2.0 b | ‒ | 8.0 ± 2.0 a† | |
| Mean height (m) | 15.4 ± 3.4 a | 10.9 ± 2.7 b | ‒ | 13.2 ± 2.6 c† | |
| Branch abundance | Total | 9759 | 6721 | ‒ | 7939 |
| Mean per transect | 325 ± 284 a | 224 ± 102 a | ‒ | 220 ± 169 a | |
| Mean per transect (< 0.5 cm diameter) | 215 ± 237 a | 142 ± 85 a | ‒ | 135 ± 151 a | |
| Mean per transect (< 2 cm diameter) | 316 ± 283 a | 219 ± 101 a | ‒ | 214 ± 168 a | |
| Epiphyte abundance | Total | 546 | 349 | 164 | 232 |
| Total adults | 211 (39%) | 153 (44%) | 86 (52%) | 101 (44%) | |
| Total attached to branches | 367 (67%) | 260 (74%) | 112 (68%) | 164 (71%) | |
| Mean per transect | 18.2 ± 20.5 a | 11.6 ± 17.8 ab | 4.6 ± 7.1 b | 6.4 ± 9.8 | |
| Mean attached to branches per transect | 12.2 ± 17.0 a | 8.7 ± 16.8 ab | 3.1 ± 5.1 b | 4.6 ± 6.4 | |
| Mean attached to branches per transect per branch | 2.8 10–3 ± 3.5 10–3 a | 2.3 10–3 ± 4.5 10–3 a | 1.1 10–3 ± 2.0 10–3 a | 1.8 10–3 ± 3.1 10–3 | |
| Epiphyte richness | Total | 23 | 16 | 27 | 39 |
| Total adults | 21 (91%) | 14 (88%) | 17 (63%) | 24 (62%) | |
| Total attached to branches | 17 (74%) | 13 (81%) | 18 (67%) | 29 (74%) | |
| Mean per transect | 5.1 ± 3.2 a | 2.3 ± 1.9 b | 1.9 ± 2.3 b | 2.8 ± 3.6 | |
| Mean attached to branches per transect | 3.3 ± 2.5 a | 1.8 ± 1.8 b | 1.4 ± 1.6 b | 2.2 ± 2.3 | |
| Mean attached to branches per transect per branch | 7.7 10–4 ± 7.1 10–4 a | 5.2 10–4 ± 5.5 10–4 a | 5.3 10–4 ± 7.5 10–4 a | 7.3 10–4 ± 7.9 10–4 | |
† indicates n = 35 (excluding one transect without trees)
Total numbers and means ± SD per study site are provided. Percentages of adults and epiphytes attached to branches to the study site totals are given in parentheses. Means were compared with simultaneous max-t tests using Tukey contrasts that are robust under non-normality, heteroscedasticity and variable sample size [34]. Significantly different means are indicated by different letters representing pairwise differences. Note that for epiphytes, only mean values for Panamanian transects without ferns and aroids were used in the comparisons with Brazilian study sites.