Title
Pine forests (Pinus sylvestris var. engadinensis, in the western part also P. uncinata) in valleys of the Inner Alps with Astragalus onobrychis, Arctostaphylos uva-ursi, Onobrychis saxatilis in combination with dry grasslands (Stipa capillata)
Geographical distribution
Country/territory
Inner Alpine (Central Alpine) dry valleys: France (Tarentaise, Maurienne, Brianconnaise); Switzerland (Lower Engadin, Albula and Rhine valley of Chur, Valais); Italy (Aosta and Vintschgau); Austria (Tyrolean Upper Inn valley)
area frequency
18 polygons.
Scientific names of main plant communities and their most common synonyms (with author citation)
a) Ononido-Pinetum Braun-Blanquet 1949 (focal point dry valleys of the west Alps), b) Erico-Pinetum sylvestris Braun-Blanquet in Braun-Blanquet et al. 1939 (focal point dry valleys of the east Alps); Italy: Astragalo-Pinetum, Ononido-Pinetum.
Structural feature of the main community(ies) (layers, life-forms, etc.)
a) Open pine forests with a sparse shrub layer and usually a more closed chamaephyte and tuft-forming plant layer. In the tree layer the wide-canopied pine reaches 8-10 (20) m in height. Mosses are sparse. b) In the tree layer poor-growing, rough-barked common (Scots) pines normally dominate with a marked umbrella-shaped crown that seldom exceeds 10 m in height. At higher altitudes above 1000 m the pine clearly grows better. Spruce and larch are sprinkled about, while at lower altitudes the oak penetrates, and the whitebeam also occurs in tree form. An open shrub layer with numerous thermophilous species. An opulent moss layer. On dry, sun-facing dolomite and hard limestone slopes, and on porous rock sites.Italy: Four-layered, high-growing pine forests with Pinus sylvestris in the tree and shrub layers, Berberis vulgaris, Juniperus communis and with steppe elements in the herb layer.
Dominant and most frequent species in different layers
Tree layer
a-b) Pinus sylvestris, Picea abies, Larix decidua, Sorbus aria, Quercus pubescens
Shrub layer
a-b) Amelanchier ovalis, Juniperus communis, Juniperus sabina, Berberis vulgaris, Cotoneaster tomentosus, Rhamnus saxatilis, Viburnum lantana, Ligustrum vulgare, Prunus mahaleb, Hippocrepis emerus, Colutea arborescens
Lianas
epiphytes: Viscum album subsp. austriacum
Herb layer
a) Carex humilis, Arctostaphylos uva-ursi, Ononis rotundifolia, Astragalus onobrychis, Astragalus monspessulanus, Astragalus vesicarius subsp. pastellianus, Astragalus exscapus, Odontites viscosa, Saponaria ocymoides, Coronilla minima, Carex halleriana, Viola rupestris, Pyrola chlorantha, Oxytropis pilosa, Oxytropis halleri subsp. velutina;
b) Erica carnea, Carex alba, Melampyrum pratense subsp. pratense, Goodyera repens, Buphthalmum salicifolium, Dorycnium pentaphyllum subsp. germanicum, Leontodon incanus, Anthericum ramosum, Prunella grandiflora, Vincetoxicum hirundinaria, Sesleria albicans; in both main units: Polygala chamaebuxus, Gymnadenia odoratissima, Epipactis atrorubens, Euphorbia cyparissias, Peucedanum oreoselinum, Galium lucidum, Teucrium chamaedrys, Thymus praecox
Moss layer (incl. lichens)
a) missing;
b) Rhytidium rugosum, Scleropodium purum, Pleurozium schreberi, Hylocomium splendens, Rhytidiadelphus triquetrus, Dicranum polysetum; additionally Italy: Thuidium abietinum, Hypnum cupressiforme, Dicranum scoparium, Tortella tortuosa
Diagnostically important species
Pinus sylvestris; Erica carnea, Ononis rotundifolia, Odontites viscosa, Onobrychis saxatilis, Astragalus spp.; additionally Italy: Astragalus monspessulanus, Astragalus exscapus, Astragalus vesicarius subsp. pastellianus, Oxytropis halleri subsp. velutina
Ecological variants
In areas where both main units (a, b) occur next to one another (dry valleys of the western Alps e.g. Valais), communities of the Ononido pinion colonise the driest and most immature sites, while the Erico-Pinetum settles less dry and immature sites. In the dry valleys of the eastern Alps (Great Tyrolean valleys) only the Erico-Pinetum dominates most of the time.Onobrycho-Pinetum: Durance region (France); Ononido-Pinetum: Maurienne (France), Valais-Engadin (Switzerland), Upper Inn Valley (Tyrol, Austria); Astragalo-Pinetum: Vintschgau (Italy).Dry grassland (France; Italy: Aosta); Stipo-Poion carniolicae (Switzerland: Valais, Engadin); Stipeto-Poion xerophilae (Austria); Diplachnion (Italy: Susa-Valtellina-Etsch-Eisack).
Geographical variants (geogr. differential species)
In the central Alps with Astragalus vesicarius subsp. pastellianus, Oxytropis halleri subsp. velutina; stands of the Erico-Pinetum in the eastern Alps contain some east Alpine species such as Leontodon incanus and Dorycnium pentaphyllum subsp. germanicum that disappear completely in the western Alps. Erica carnea is also comparably rare in the western Alps and is frequently replaced by Carex alba as the stand-forming species of the ground layer vegetation. In contrast, the west Alpine stands contain a whole range of xerophytes of southwestern distribution, such as Coronilla minima, Onobrychis saxatilis and Lavandula angustifolia.
Natural accompanying vegetation (most important units in complex with the name giving mapping unit, scientific names)
Astragalo-Pinetum at sun-exposed southern slopes with poorly developed shallow siliceous soils. In Switzerland there are larger dry areas (particularly Engadin, Valais), sometimes interdigitating with Quercetalia pubescentis; Stipeto-Poion xerophilae, Stipeto-Poion carniolicae; in Italy dry grassland of the Festucetalia valesiacae and the Stipeto-Poion xerophilae alliance.
Adjoining climax and permanent vegetation (with numbers of mapping units)
alpine grasslands (B43), larch-pine forests (C19), spruce forests (D35), species-poor and species-rich beech and mixed beech forests (F101, F133), downy oak forests (G40, G48).
Land use, substitute communities
forestry (substitute communities, plantations of economic tree-species, scrub)
Pinus nigra plantations (covering large areas in the Val Venosta), Larix decidua and Picea abies plantations, Berberidion scrub (particularly Berberido-Rosetum), on abandoned dry grasslands Juniperus sabina espalier and scrub consisting of Juniperus communis and Hippophae rhamnoides.
grassland (meadows, pastures, herb-rich communities)
short-grass meadows; dry grassland (Xerobromion); Festucetalia valesiacae (Stipeto-Poion xerophilae) and often secondary substitute communities.
arable land (characteristic weed communities)
occasionally stony crop fields; vineyards.
settlements (typical ruderal vegetation)
Italy: Echinopseto-Artemisietum, Artemisio-Agropyretum.
Site conditions of the mapping unit
Landscape type, geomorphology
mountain valleys and slopes; at rock-scattered, south exposed steep slopes, on debris fields, alluvial fans and young landslide masses, at erosion slopes in open sediments, on gravel terraces of alpine rivers, extremely dry ribs and rocky ridge backs.
Altitudinal belt and/or altitudinal range
(sub)montane to altimontane; 500-1400 m
Geology (bedrock)
dolomite and lime (carbonate rocks) as well as their redeposition and disaggregation product (moraines, talus), also on silicate locations covered with calcareous bluff formation or moraines; (Mesozoic, Palaeozoic)
soil type, also the depth of fine textured earth (soil), stone content; (international nomenclature)
shallow humus carbonate soils and para-humus carbonate soils, more rarely ranker, brown soils; strongly distinct tendency to form xero-mull-like mor; mostly very high stone content. Italy: leached and acidic brown soils (Mancini 1966); (stony, dystric and lithic leptosols; lithic dystric cambisols)
soil texture
silty-sandy to stony
soil moisture, water balance
moderately dry to very dry
soil reaction
mineral soil neutral to alkaline; mor (xero-mull-like mor) often acidic to weakly acidic
soil fertility
meso-eutrophic to eutrophic; (lime)oligotrophic to oligo-mesotrophic
Climate incl. local climate
climate type (following Walter & Lieth)
IV(VI)2, IV(X), VI4, VI(X)1, VI(X)2
average annual temperature
8-12 °C
average annual precipitation
450-800 (1000) mm
average temperature of the warmest month
July 16-21 °C
average temperature of the coldest month
January (-4) -1 to 2 °C
local climate or other climatic peculiarities
continental character; sites poor in precipitation, summerly dry seasons; foehn valley, foehn undercut slopes, mostly exposed to the sun.
Importance for nature protection
Present state and development trend of natural vegetation (degree of endangerment)
Varies considerably; e.g. in the Upper Inn valley there are large primary stands in a very semi-natural state, but replaced by secondary dry grasslands and Pinus nigra plantations over large areas in the Val Venosta and Aosta valley. Secondary stands in the area of potential downy oak forests (of large size e.g. in the lower montane belt of the middle Valais) undergo rapid succession after cessation of degrading activities (forest grazing).
endangered communities, species worthy of protection in natural vegetation
All nearly-natural pine communities and arid grassland; relict-species: for instance Astragalus alopecurus, Kochia prostrata, Artemisia vallesiaca, Ephedra distachya; species worthy of protection in Italy: Astragalus exscapus, Astragalus vesicarius subsp. pastellianus, Ononis rotundifolia, Oxytropis halleri subsp. velutina.
causes of endangerment
Erosion at high altitudes, refuse dumping, construction activity (expansion of settlements and traffic routes), agricultural use (e.g. viniculture in the Valais and Val Venosta), forestry, waterway engineering (e.g. Rhone).
required measures for protection and restitution
The best semi-natural stands should be placed under protection.
Localities of representative stands (loci typici) with state of protection
of the natural vegetation
France: Queyras, St. Crèpin (with Juniperus thurifera), Argentiere, surroundings of Briancon, upper Maurienne between St. Nicolas and Aosta; Switzerland: Valais (Burgberg of Sion, Pfynnwald near Sierre, slopes between Leuk and Albinen), Flims' Bergsturz in the Rhine valley of Chur; Austria: Virgental (Hinterbichl-Obermauern), Lungau (Jedl-Schellgaden), Martinswand and Kalvarienberg near Zirl, Tschirgant-Bergsturz at the end of the Ötz valley, dolomite-scree-nests at the southern slope of the Lech valley Alps west of Landeck; Italy: Val d’Aosta, Glurns (Upper Vintschgau).
of characteristic substitute communities worthy of protection
Extensive, arid grassland-vegetation complexes characterizing the landscape for instance in the Vintschgau, Aosta valley and Valais. Within the range of the Upper Inn valley, the Lower Engadin and the Rhine valley of Chur by now only very small-scaled and highly endangered.
Most important references (author, year)
Bartoli 1966; Braun-Blanquet 1917; Braun-Blanquet 1961; Braun-Blanquet, Pallmann & Bach 1954; Braun-Blanquet & Richard 1949; Gams 1930; Hölzel 1996a; Hölzel 1996b; Mayer 1974; Mayer 1984; Ozenda 1966; Pedrotti, Orsomando & Cortini Pedrotti 1974; Plumettaz Clot 1988; Schmid 1936; Wagner 1979; Wagner 1989
Compiled by
J. Niedbala referring to H. Wagner, completed by K. Zukrigl, F. Klötzli; F. Pedrotti and Z. Neuhäuslová; N. Hölzel
