G41: Downy oak forests (Quercus pubescens) with Buxus sempervirens, Genista cinerea, partly Acer opalus from the south Pyrenees to the southwest pre-Alps

Title

Downy oak forests (Quercus pubescens) with Buxus sempervirens, Genista cinerea, partly Acer opalus from the south Pyrenees to the southwest pre-Alps

Geographical distribution

Scientific names of main plant communities and their most common synonyms (with author citation)

Buxo sempervirentis-Quercetum pubescentis Braun-Blanquet 1931, 1932 in Braun-Blanquet et al. 1952.

Structural feature of the main community(ies) (layers, life-forms, etc.)

Quite closed, moderately-high forests in which Quercus pubescens (10-12 m) prevails in the tree layer accompanied by Acer and Sorbus species. The shrub layer is rich in Buxus sempervirens and other woody plants. In the herb layer numerous thermophilous and some mesophilous forest species including geophytes are present.

Dominant and most frequent species in different layers

Diagnostically important species

Quercus pubescens, Acer monspessulanum; Buxus sempervirens, Genista hispanica, Rhamnus saxatilis, Cytisophyllum sessilifolium, Amelanchier ovalis; Lonicera etrusca, Primula veris subsp. columnae, Knautia purpurea

Ecological variants

Lowland form with Spartium junceum, Juniperus phoenica (on rocky substrate), Juniperus oxycedrus, Rhamnus alaternus, Cephalaria leucantha as well as other species of the Quercetea ilicis; high altitude form, that transcends into the Querco-Aceretum opali Br.-Bl. 1952. The stands of the Querco- Aceretum opali colonise southern slopes at higher altitudes and occur at lower altitudes on north-facing slopes. In addition to Quercus pubescens, Quercus petraea and other oaks are found in the tree layer. The mesophilous subassociation transcends into the Ilici-Quercetum pubescentis Barbéro & Quézel 1995 with Ilex aquifolium and up to 30 other species in the shrub layer. The forests are found on northern slopes, slope bases and on relatively deep soils in eastern Provence (St. Baume). In addition to a subassociation with Acer monspessulanum, a subassociation with Taxus baccata at shady sites and a subassociation on high-lying debris slopes with Sorbus aria and Tilia platyphyllos.

Geographical variants (geogr. differential species)

France: various geographic strains (Provencale form with Daphne laureola, Rubia peregrina, Inula spiraeifolia, Lathyrus latifolius). Spain: a) pinetosum pyrenaicae: altimontane form in the area of Jaca and the Sierra Guara with Pinus sylvestris var. pyrenaica; b) quercetosum subpyrenaicae: submontane form in the area of Jaca and the Sierra Guara with Quercus pubescens; c) hylocomietosum splendentis: shaded stands on base-deficient soils of the Sierra del Cadí with Hylocomium splendens; d) Pyrenean form with Tilia platyphyllos, Lavandula angustifolia subsp. pyrenaica.

Natural accompanying vegetation (most important units in complex with the name giving mapping unit, scientific names)

France: Forests of the Cephalanthero-Fagion with Buxus sempervirens; rubble vegetation with Achnatherum calamagrostis, Rumex scutatus and Epilobium dodonaei; rock fissure communities. Spain: at watercourses Salicion elaeagni and Hyperico androsaemi-Alnetum glutinosae with Lonicera xylosteum, Viburnum lantana.

Adjoining climax and permanent vegetation (with numbers of mapping units)

larch-pine forests (C19), acidophilous oak forests (F16, F26), oak-mixed oak forests (F33), sessile oak-hornbeam forests (F52, F53), species-poor (mixed) beech forests (F82, F92, F98, F100), species-rich beech and beech forests (F129, F132, F136, F137, F138, F139, F141), downy oak forests (G38, G42), flowering ash-downy oak orests (G44), Quercus faginea-forests (G72), Quercus ilex subsp. rotundifolia-forests (J4, J8, J12), holm oak forests (J15, J17), cork oak forests (J27), wild olive tree-locust tree forests (J48), pine forests (K4, K5), alluvial forests (U33).

Land use, substitute communities

Site conditions of the mapping unit

Importance for nature protection

Localities of representative stands (loci typici) with state of protection

Most important references (author, year)

Biurrun, García-Mijangos & Loidi Arregui 1994; Braun-Blanquet, Roussine & Nègre 1952; Carreras, Carrillo, Font, Ninot, Soriano & Vigo Bonada 1995; Loidi Arregui, Biurrun Galarraga & Herrera Gallastegui 1997; Loidi Arregui, Díaz González & Herrera Gallastegui 1997; Molinier 1939; Ozenda 1981; Peinado Lorca & Rivas-Martínez (Ed.) 1987; Rameau 1996b; Rameau 1997; Rivas-Martínez 1987; Rivas-Martínez, Bascones, Díaz González, Fernández-González & Loidi Arregui 1991a; Rivas-Martínez, Bascones, Díaz González, Fernández-González & Loidi Arregui 1991b

Compiled by

for France: Z. Neuhäuslová based on documents by J. Braun-Blanquet; C. Hettwer based on documents by J.-C. Rameau; for Spain: J. Loidi; A. Penas Merino and L. Herrero Cembranos; V. Voggenreiter based on documents by S. Rivas-Martínez