sentences:  The forests seek watercourses and shade, and so their reforestation is very difficult and they are being displaced by the Pyrenean Oak ("Quercus pyrenaica").The Irati "rainforest", of some 170 square kilometres in the Navarran Pyrenees, is one of the most important beech and fir forests in Europe.Oak forests, above all of pedunculate oak ("Quercus robur"), are the most common in the Atlantic zone.