Table 2.
Summary of predictor variables used for machine learning modeling
| No. | Product and its description | Predictor’s | Data | Data |
|---|---|---|---|---|
| type | source | resolution | ||
| 1 | Altitude as derived from digital elevation model (DEM) | Spatial | SRTM-3 | ca. 1 km |
| 2–3 | Geographical coordinates (in the projected coordinate system) | Spatial | – | |
| 4 | Distance to the Baltic Sea coast | Spatial | – | |
| 5–16 | Monthly mean air temperatures (Jan–Dec) | Meteo | E-OBS | ca. 27 km |
| 17 | Monthly mean air temperatures of previous’ year December | Meteo | E-OBS | ca. 27 km |
| 18–21 | Seasonal mean air temperatures of previous’ year | Meteo | E-OBS | ca. 27 km |
| 22–23 | Mean air temperatures of winter and spring seasons | Meteo | E-OBS | ca. 27 km |
| 24–35 | Total monthly precipitations (Jan–Dec) | Meteo | E-OBS | ca. 27 km |
| 36 | Total monthly precipitations of previous’ year December | Meteo | E-OBS | ca. 27 km |
| 37–45 | Cumulative growing degree days (GDD) | Meteo | E-OBS | ca. 27 km |
| from 0 to 8 ∘C with an interval of 1 ∘C | ||||
| 46 | Cumulative growing precipitation days (GPD) | Meteo | E-OBS | ca. 27 km |
| 47 | Presence of snow cover (0–1) | MODIS | IMS | 4 km |
| 48–49 | Consecutive number of days with and without snow cover | MODIS | IMS | 4 km |
| 50 | Number of days with snow cover in a month | MODIS | IMS | 4 km |
| 51 | Day of year with the last snow cover | MODIS | IMS | 4 km |
| NDVI, EVI, LAI, and fPAR means aggregated in AtPol 10 × 10-km grid: | MODIS | MYD13Q1 / | 0.25–1 km | |
| MOD13Q1 | ||||
| 52–55 | - For all available values | MODIS | – || – | 0.25–1 km |
| 56–59 | - Based only on the highest pixel reliability (i.e., flagged as “0”) | MODIS | – || – | 0.25–1 km |
| 60–63 | - Based only on the highest and average pixel reliability (“0–1”) | MODIS | – || – | 0.25–1 km |
| 64–67 | - Based on all available except the lowest pixel reliability (“0–2”) | MODIS | – || – | 0.25–1 km |
| 68–79 | - 1-week rolling mean group by pixel reliability (“0,” “0–1,” “0–2”) | MODIS | – || – | 0.25–1 km |
| - The rate of change grouped by pixel reliability (“0,” “0–1,” “0–2”) between: | ||||
| 80–91 | – Monthly and 10-day average | MODIS | – || – | 0.25–1 km |
| 92–103 | – 10-day average and one-week rolling mean | MODIS | – || – | 0.25–1 km |
| 104–115 | - Normalized for particular pixel’s location and | MODIS | – || – | 0.25–1 km |
| grouped by pixel reliability (“0,” “0–1,” “0–2”) |