Cultural and degradation stages of poor oak-fir stands on pseudogley soils

abies analisis analyse analyse chimique analysis arbre arbre forestier arbre pour bois de construction chemical analysis conifere conifers crops cultivos cultural soil types dicotiledoneas dicotyledons ecologia ecological soil types ecologie ecology economic plants environment environnement fagaceae fagales forest ecology forest soils forest trees gimnospermas gymnosperme gymnosperms medio ambiente methode methods pinaceae plantas plante plante de culture plante pour construction plants quercus site factors soil types structural crops suelo forestal timber trees trees type de sol type de sol de culture