| Table 1. Seed zone/region with coordinates in degrees latitude and longitude, approximate elevation and harvest year of provenances. | ||||
| Seedlot | Seed zone / Region | Approx. location | Approx. elevation | Harvest yr. |
| Finland | B. pendula – Region 1 (Lahti, Southern Finland) | 60° N; 25° E | 90 m | 2002 |
| Scotland | UK201 (Scottish Highlands, Grantown on Spey) | 57° N; 03° W | 275 m | 2001 |
| England | UK301 (England Keswick, Cumberland) | 55° N; 03° W | 100 m | 2009 |
| England | UK403 (Central England, Nesscliffe, Shropshire) | 53° N; 03° W | 75 m | 2010 |
| France | BPE 901-montagne (East France – Rhône-Alpes) | 47° N; 05° E | 230 m | 2010 |
| Table 2. Total number of seeds tested in each provenance, pure seed moisture content and average and standard deviation of number of filled and empty seeds in a 0.1 g sample. | ||||
| Provenance | Total number of seeds | Moisture content (%) | Filled seeds (Average ± SD) | Empty seeds (Average ± SD) |
| Finland | 8440 | 9.7 | 108 ± 11 | 43 ± 16 |
| UK201 | 10454 | 9.6 | 56 ± 13 | 130 ± 23 |
| UK301 | 9001 | 6.5 | 48 ± 11 | 112 ± 20 |
| UK403 | 10144 | 10 | 88 ± 14 | 94 ± 17 |
| France | 12966 | 7.2 | 79 ± 15 | 156 ± 24 |
Fig. 1. Maximum germination capacity (at day 21) for five provenances of Betula pendula expressed as a percentage of filled seed. Closed symbols: germination following pre-chilling (PC). Open symbols: germination of control seeds (NPC). Error-bars: Standard error.
| Table 3. Thermal time parameters (with standard errors) of Betula pendula: estimated base temperature (Tb) in °C; thermal time to 50% germination (θ50) in degree-weeks for both treatments (NPC and PC); relative change in parameters after pre-chilling (PC – NPC). | ||||||||||
| Provenance | Control seeds (NPC) | Pre-chilled seeds (PC) | PC – NPC | |||||||
| Tb | S.E. | θ50 | S.E. | Tb | S.E. | θ50 | S.E. | Tb | θ50 | |
| Finland | 15.8 | 0.8 | 21.2 | 1.4 | 10.3 | 0.9 | 13.4 | 1.2 | 5.6 | 7.8 |
| UK201 | 13.1 | 2.2 | 37.9 | 5.0 | 6.8 | 1.1 | 23.6 | 2.0 | 6.3 | 14.3 |
| UK301 | 9.4 | 1.8 | 37.4 | 3.7 | 7.5 | 0.9 | 16.8 | 1.3 | 1.9 | 20.6 |
| UK403 | 12.6 | 1.0 | 28.1 | 2.0 | 10.2 | 1.0 | 14.8 | 1.4 | 2.4 | 13.2 |
| France | 12.3 | 1.9 | 42.5 | 4.8 | 9.9 | 1.1 | 19.6 | 2.0 | 2.5 | 23.0 |
Fig. 2. Predicted germination of seeds from Finland (FIN), Scotland (UK201), north England (UK301), central England (UK403) and Eastern France (FRA) provenances under conditions that simulate a mild (NPC) and slightly colder winter (PC) in southern England.