Table 2.
Selection gradients (β) from multiple linear regressions for selection exerted on black pine by crossbills at two sites, Samarina and Aetia (n = 78 and 96 trees, respectively)
| Samarina | Aetia | |||
|---|---|---|---|---|
| Trait | β ± SE | 95% CI | β ± SE | 95% CI |
| Number of cones | −0.0089 ± 0.0299 | −0.0760, 0.0437 | −0.0032 ± 0.0019 | −0.0076, −0.0005 |
| DBH | −0.0162 ± 0.0355 | −0.0856, 0.0533 | 0.0039 ± 0.0017 | 0.0014, 0.0079 |
| Cone width/length | −0.0098 ± 0.0216 | −0.0537, 0.0312 | −0.0016 ± 0.0008 | −0.0033, 0.0001 |
| Scale thickness | 0.0599 ± 0.0186 | 0.0247, 0.0985 | 0.0003 ± 0.0011 | −0.0019, 0.0025 |
| Number of full seeds | −0.0149 ± 0.0177 | −0.0486, 0.0205 | 0.0018 ± 0.0010 | −0.0001, 0.0039 |
| Number of empty seeds | 0.0339 ± 0.0166 | 0.0026, 0.0705 | 0.0023 ± 0.0011 | 0.0006, 0.0048 |
| Individual seed mass | 0.0599 ± 0.0233 | 0.0146, 0.1075 | 0.0020 ± 0.0013 | −0.0002, 0.0049 |
The overall models for Samarina and Aetia were significant (P < 0.0001 and P = 0.001, respectively). Selection gradients that do not overlap with the 95% confidence intervals (P < 0.05) are in bold. VIF < 2 for all traits in both models, |r| < 0.38 for all trait correlations.