Table 3.
Results of the principal component analysis of the 19 bioclimatic variables extracted from the regions in South Korea that the red-tongued pit viper (Gloydius ussuriensis) inhabits.
| Variable | PC1 | PC2 | PC3 | |
|---|---|---|---|---|
| % Variance explained | 47.25% | 26.97% | 17.83% | |
| Eigenvalue | 2.996 | 2.264 | 1.841 | |
| bio1 | Annual temperature | 0.291 | 0.080 | 0.241 |
| bio2 | Mean diurnal range | −0.242 | 0.233 | 0.134 |
| bio3 | Isothermality | − 0.144 | 0.333 | 0.110 |
| bio4 | Temperature seasonality | − 0.303 | − 0.092 | 0.128 |
| bio5 | Maximum temperature of the warmest period | 0.094 | 0.118 | 0.485 |
| bio6 | Minimum temperature of the coldest period | 0.329 | 0.004 | 0.041 |
| bio7 | Temperature annual range | − 0.312 | 0.040 | 0.137 |
| bio8 | Mean temperature of the wettest quarter | 0.168 | 0.051 | 0.454 |
| bio9 | Mean temperature of the driest quarter | 0.320 | 0.074 | 0.058 |
| bio10 | Mean temperature of the warmest quarter | 0.176 | 0.037 | 0.449 |
| bio11 | Mean temperature of the coldest quarter | 0.319 | 0.080 | 0.094 |
| bio12 | Annual precipitation | − 0.018 | 0.421 | − 0.032 |
| bio13 | Precipitation of the wettest period | − 0.227 | 0.282 | 0.074 |
| bio14 | Precipitation of the driest period | 0.114 | 0.319 | − 0.228 |
| bio15 | Precipitation seasonality | − 0.282 | − 0.119 | 0.185 |
| bio16 | Precipitation of the wettest quarter | − 0.144 | 0.370 | 0.039 |
| bio17 | Precipitation of the driest quarter | 0.181 | 0.295 | − 0.243 |
| bio18 | Precipitation of the warmest quarter | − 0.187 | 0.334 | 0.076 |
| bio19 | Precipitation of the coldest quarter | 0.186 | 0.286 | − 0.247 |
The first four principal components (PCs) with eigenvalues larger than one are represented here. The percentages indicate the amount of variation explained by each PC, and the components that were loaded most highly for each parameter are in bold font.