THE BEECH (Fagus sylvatica)
The beech grows at mountain level, between about 800 and 1,800 m in humid conditions with condensation forming thick fog, drizzle or rain. Though not fussy about the soil, beech trees can be badly affected by late frosts, which destroy tender young leaves and blooms. Where trees are tightly packed, few other species grow in the humus.
Size: up to 30 or 40 metres tall with a trunk often over one metre in diameter.
Lifetime: between 300 and 500 years
Bark: smooth and grey with horizontal ridges and patches of lichen
Foliage: deciduous; light green in spring, dark in summer turning to golden yellow or brown in autumn. The leaves and vein angles are edged with small hairs.
Fruit: ripe by late September, the almond-shaped beechnuts are grouped by twos or threes in a husk covered in soft spikes.
Use: fuel, woodwork and paper.
Habitat: beech trees grow as well on the plain as in mountainous areas. They like shade and moisture. in the Pyrenees they are found at the mountain level of northern slopes throughout the range.
THE SILVER FIR (Abies pectinata)
The silver fir is often found among beech trees where it can be spotted by its tall, dark silhouette. It is also found growing in 100% fir forests, especially in shady spots near the top of the mountain level (around 1,800 m). Another tree that will grow in different types of soil, silver firs form a shady, silent cover for undergrowth.
Size: Giant of the Pyrenees, the silver fir can grow to 50 m
Bark: the silver-grey bark cracks and becomes scaly over time.
Foliage: evergreen. The needles spread out horizontally on either side of the branch. Shiny green on the upper side, two silver-white bands on the underside. The top tends to flatten out with age.
Fruit: the cones remain upright on the top branches. In the autumn the cones break up, leaving the central spike still standing upright like a candle.
Use: good timber. Its resin has medical virtues.
Habitat: the silver fir forms magnificent forests at altitudes of between 500 and 1,600 metres. In the Pyrenees they are found mixed with beech or in 100% fir populations.
By Matias Dorr Mansilla, Forest correspondent