New and firm evidence for mid-Holocene appearance of Picea abies in the Scandes Mountains, Sweden

age structure anillo de crecimiento arbre forestier cerne clima climat climate crecimiento croissance dendrochronologie dendrochronology dendrocronologia ecologia ecologie ecology estructura por edades forest trees growth growth rings highlands histoire historia history mountains palaeontology paleontologia paleontologie picea abies plant habit port de la plante stand characteristics suecia sweden vegetation