Fig 1.
Map of the tree-ring sampling site and meteorological station in this study.
Table 1.
Tree-ring sampling point information.
| Sample site | Longitude | Latitude | Elevation (m) | Species | Aspect | Canopy closure |
|---|---|---|---|---|---|---|
| High | 81°02′2.37″ | 43°24′37.48″ | 2800–2810 | P. schrenkiana | N | 0.1 |
| Middle | 81°02′6.41″ | 43°25′14.50″ | 2500–2565 | P. schrenkiana | N | 0.2 |
| Low | 81°07′12.34″ | 43°27′54.69″ | 2000–2100 | P. schrenkiana | N | 0.7 |
[i] P. schrenkiana, Picea schrenkiana.
Fig 2.
Meteorological data.
Fig 3.
Variation of tree-ring width index at different elevations.
Table 2.
Statistical features of tree-ring width standardised chronology at different elevations.
| Statistical characteristics | High | Middle | Low |
|---|---|---|---|
| Percentage of the first eigenvector | 0.285 | 0.397 | 0.451 |
| Mean within-tree correlation coefficient | 0.158 | 0.313 | 0.409 |
| Signal-to-noise ratio | 6.807 | 13.946 | 28.146 |
| Representative of the sample to the population | 0.872 | 0.933 | 0.966 |
| Standard deviation | 0.226 | 0.183 | 0.279 |
| Mean sensitivity | 0.171 | 0.126 | 0.210 |
| First-order autocorrelation coefficient | 0.589 | 0.653 | 0.596 |
Fig 4.
Correlations between the tree-ring width chronologies and the meteorological data at different elevations.
Fig 5.
Moving correlation between the tree-ring width chronology and meteorological data at different elevations.