Table 2 Environmental indicators used as predictors of stand BAI. Temporal average indicators were extracted from GIS data. Historical indicators were either extracted from climatic series or estimated from the NFI field plot data contemporary to growth measurements (section 3 of Materials). P and PET (in italics) were used as intermediate variables in the calculation of bioclimatic indicators and were not retained as candidate predictors. Cited references are reported in the reference list.
| Â | Temporal average indicators (GIS data) | Historical indicators | |||||||
|---|---|---|---|---|---|---|---|---|---|
Variable | Abrev. | Unit | Source/Method | Spatial resolution | Temporal resolution | Abrev. | Unit | References | Temporal resolution |
Monthly radiation | Rad | MJ.m−2 | Piedallu and Gégout 2007 (HELIOS model) | 1 km | 30-year normal (1971–2000) | Radh | MJ.m−2 | Piedallu and Gégout 2007 (HELIOS model) | 30 years average (1971–2000) |
Monthly minimal temperature | Tn | °C | Bénichou and Le Breton 1987 (AURELHY model) | 1 km | 30-year normal (1961–1990) | Tnh | °C | Météo-France historical data | Monthly |
Monthly maximal temperature | Tx | °C | Bénichou and Le Breton 1987 (AURELHY model) | 1 km | 30-year normal (1961–1990) | Txh | °C | Météo-France historical data | Monthly |
Monthly precipitation | P | mm | Bénichou and Le Breton 1987 | 1 km | 30-year normal (1961–1990) | Ph | mm | Météo-France historical data | Monthly |
Monthly potential evapotranspiration | PET | mm | Turc 1961 | 1 km | 30-year normal (1961–1990) | PETh | mm | Turc 1961 | Monthly |
Monthly water balance | CWB | mm | P-PET | 1 km | 30-year normal (1961–1990) | CWBh | mm | Ph-PETh | Monthly |
Soil water holding capacity | SWC | mm | Piedallu et al. 2011 | 500 m | Permanent | SWCh | mm | NFI soil data + Piedallu et al. 2011 | Permanent |
Soil water budget | SWB | mm | calculated from SWC, P and PET | 1 km | 30-year normal (1961–1990) | SWBh | mm | Calculated from SWCh, Ph and PETh | Monthly |
Soil water deficit | SWD | mm | calculated from SWC, P and PET | 1 km | 30-year normal (1961–1990) | SWDh | mm | calculated from SWCh, Ph and PETh | Monthly |
pH | pH | – | Gégout 2008 | 1 km | 15-year average (1989–2004) | pHh |  | NFI floristic data + bio-indication (Gégout et al. 2003) | Punctual |
S/T ratio | S/T | % | Piedallu, comm. pers. | 1 km | 15-year average (1989–2004) | S/Th | % | NFI floristic data + bio-indication (Gégout et al. 2003) | Punctual |
C/N ratio | C/N | kg.kg−1 | Piedallu, comm. pers. | 1 km | 15-year average (1989–2004) | C/Nh |  | NFI floristic data + bio-indication (Gégout et al. 2003) | Punctual |