Votre recherche

This study presents the results of a floristic vegetational study on Robinia pseudoacacia neoformation forests in the peri-Adriatic sector of central Italy. This has allowed the characterization of these coenoses at the ecological, biogeographic, syntaxonomic and landscape levels. These currently represent the southernmost syntaxa of the Robinietea class described for the Italian peninsula, and the first syntaxonomic contribution of this class in Europe for the Mediterranean biogeographical region. We propose here the new alliance Lauro nobilis–Robinion pseudoacaciae of the order Chelidonio–Robinietalia pseudoacaciae and class Robinietea, with two new associations: Melisso altissimae–Robinietum pseudoacaciae and Rubio peregrinae–Robinietum pseudoacaciae. The new alliance Lauro nobilis–Robinion pseudoacaciae (typus: Melisso altissimae–Robinietum pseudoacaciae) brings together neoformation forests and pre-forest dominated by R. pseudoacacia in those territories with a Mediterranean macroclimate of the peri-Adriatic sector of central Italy. The optimum is found for the alluvial plain and low-slope morphologies, on soils that are moist and rich in organic matter and in areas with anthropic disturbance. On the basis of comparisons with the European context, the alliance Bryonio–Robinion described for the temperate territories of northern Italy is here validated.

Cette monographie est consacrée à l’étude phytosociologique des versants des coteaux marneux du Pays de Serres situés dans le département du Lot-et-Garonne. Seul le système xérophile est étudié et a permis d’individualiser deux végétations de pelouses (une association des versants thermophiles et une autre de pelouse-ourlet des versants sous-exposés), une parvochaméphytaie, un fourré d’arbrisseaux, un fourré et une communauté arborée. Elle a permis de décrire trois nouvelles associations : le Platanthero bifoliae - Molinietum arundinaceae , l’Helichryso stoechadis - Dorycnietum pentaphylli et le Junipero communis - Prunetum mahaleb Julve & Marchal, ainsi que la sous-association dorycnietosum pentaphylli du Staehelino dubiae - Teucrietum chamaedryos. Des discussions sont également engagées sur la possibilité de distinguer les parvochaméphytaies des Rosmarinetea officinalis sous climat thermo-atlantique et sur la position syntaxinomique des fourrés d’arbrisseaux basophiles.

Cet article est une contribution à l’amélioration des connaissances des végétations du sud-ouest de la France (Nouvelle-Aquitaine). Nous proposons ici une nouvelle association d’ourlet acidiphile thermo-atlantique, l’Arenario montanae–Pseudarrhenatheretum longifolii ass. nov. que nous positionnons dans le contexte de la succession végétale des Landes de Gascogne. Nous présentons également les différentes végétations qui s’insèrent dans cette succession en contexte naturel, c’est-à-dire évoluant vers une forêt de feuillus et en contexte de sylviculture intensive de Pinus pinaster. Mots-clés : Aquitaine, phytosociologie, Landes de Gascogne, Arenario montanae–Pseudarrhenatheretum longifolii, Pino pinastri–Quercetum roboris

Here is proposed the declination of the Carpino betu- li-Fagetea sylvaticae Jakucs 1967 class, for the second version of the French vegetation prodrome (PVF2). Divided in 2 sub-classes, it contains 177 associations (165 are fully described in separated sheets), 16 sub-alliances, 17 alliances, 8 sub-orders and 5 orders. This class comes from the splitting of the Querco robo- ris-Fagetea sylvaticae Braun-Blanq. & Vlieger in Vlieger 1937 « superclass », chosen in the first French vegeta- tion prodrome (PVF1, Bardat et al., 2004), as two other ones (Quercetea pubescentis Doing-Kraft ex Scamoni & H. Passarge 1959 and Quercetea robori-petraeae Braun-Blanq. & Tüxen ex Braun-Blanq., Roussine & Nègre 1952).Some other changes has been made compared to the PVF1, also based on an analysis of 16,455 relevés and a critical analysis of choices made in the main vegetation prodromes across western and central Europe. Ecological determinism of each vegetation units has not been forgotten, neither than structural matters and a special importance granted to the trees dominating the canopy in mature stands. Carpino betuli-Fagetea sylvaticae class is split in 2 sub- classes. The first is the Geranio robertiani-Fraxinenea excelsioris and correspond to wet, ravine or scree broadleaf hardwood forests, sharing many nitrogen rich tall herbs with the Galio aparine-Urticetea dioicae H. Passarge ex Kopecky 1969, because of the natural disturbances (flooding, rock avalanches…). The se- cond is the Fagenea sylvaticae, dominated by shade tolerant climax species (mostly beech and white fir). Compare to the PVF1, the main changes deriving from this structure concerns ravine or scree forests and non-alluvial wet oak forests. 2 new orders are proposed in the Geranio robertiani-Fraxinenea excel- sioris, in addition to the former and unchanged order Populetalia albae Braun-Blanq. ex Tchou 1949: the Ulmo-Fraxinetalia excelsioris H. Passarge 1968 corres- pond to non-alluvial wet oak forests, the Aceretalia pseudoplatani Moor 1976 to scree forests. Concerning the Fagenea sylvaticae, the acidophilous order Luzulo luzuloidis-Fagetalia sylvaticae Scamo- ni & H. Passarge 1959 is proposed in addition to the Fagetalia sylvaticae Tüxen in Barner 1931. The last im- portant change is the distinction of the beech-oak- hornbeam alliance Carpino betuli-Fagion sylvaticae R. Boeuf, Renaux & J.-M. Royer in R. Boeuf 2011 from the Carpinion betuli Issler 1931, dry oak-hornbeam vege- tation described in the Quercetea pubescentis Doing- Kraft ex Scamoni & H. Passarge 1959 class. A new sub-order, the Corylo avellanae-Fraxinenalia ex- celsioris Rameau, Mansion & Dumé 1989 subord. nov., is proposed, including secondary pionneer stands, growing on former agricultural or industrial lands, or resulting of heavy overexploitation. Keywords: Querco roboris-Fagetea sylvaticae, Geranio robertiani- Fraxinenea excelsioris, Fagenea sylvaticae, broadleaf, foothill zone, mountain zone, beech, white fi r, linden, marple, oak, hornbeam, ash

Here is proposed the declination of the Quer- cetea pubescentis Doing-Kraft ex Scamoni & H. Passarge 1959 class, for the second ver- sion of the French vegetation prodrome (PVF2). It contains 35 associations, 9 sub-al- liances, 7 alliances and 3 orders. This class comes from the spliting of the Querco robo- ris-Fagetea sylvaticae Braun-Blanq. & Vlieger in Vlieger 1937 “ superclass », chosen in the first French vegetation prodrome (PVF1, Bar- dat et al. 2004). Three orders compose this class. The Quer- cetalia pubescenti-petraeae Klika 1933 corr. Moravec in Béguin & Theurillat 1984 is the central one, and contains a new alliance for acidophilous white oak forests: the Avev- ello flexuosae-Quercion pubescentis. The Cot- ino coggygriae-Fraxinetalia orni Jakucs 1960 nom. invers propos. gathers mainland ligu- rian and thyrenean forests but also corsican ones. The choice of a third order, the Querco petraeae-Carpinetalia betuli Moor ex R. Boeuf 2014, is the main change between PVF1 and this PVF2. It is based on the Carpinion bet- uli Issler 1931 alliance, reestablished in its original diagnoses as oak-hornbeam forests, without beech because of a too dry climate. In the PVF1, both beech-oak-hornbeam and dry oak-hornbeam forests were put in the Carpinion betuli. For nomenclatural, floris- tical, structural and ecological reasons, dry oak-hornbeam forests are now separated not only from beech-oak-hornbeam for- ests but aslo from oak-hornbeam copices in witch beech has been eliminated by agri- cultural and forestry practices. The Carpin- ion betuli must only be used for “ true » dry oak-hornbeam forests. Beech-oak-horn- beam (including copices) are now con- cerned by the new Carpino betuli-Fagion sylvaticae R. Boeuf, Renaux & J.-M. Royer in R. Boeuf 2011 alliance, witch belongs to another class (see Renaux et al. 2019d). Keywords : Querco roboris-Fagetea sylvati- cae Braun-Blanq. & Vlieger in Vlieger 1937, Carpinion betuli Issler 1931, white-oak for- ests, Quercus pubescens, oak-hornbeam for- ests, supramediterranean, hophornbeam forests.

The declination of the Quercetea robori-petraeae Braun-Blanq. & Tüxen ex Braun-Blanq., Roussine & Nègre 1952 class is proposed for the new French vegetation prodrome (PVF2). It contains 23 associations, 4 sub-alliances, 8 alliances and 3 orders. This class comes from the spliting of the Querco roboris-Fagetea sylvaticae Braun-Blanq. & Vlieger in Vlieger 1937 “ superclass », which appeared in the first French vegetation prodrome (PVF1, BARDAT et al., 2004). Besides the creation of a separate class, there are very few changes from the first French vegetation prodrome (PVF1, Bardat et al., 2004). This new class corresponds to the PVF1 Quercetalia roboris Tüxen 1931, except that we recognise the order of the Molinio caeruleae- Quercetalia roboris H. Passarge 1968 for the alliance Molinio caeruleae-Quercion roboris Scamoni et H. Passarge 1959 (this alliance was in the Quercetalia roboris in the PVF1). The Quercetalia roboris is increased by two new alliances, a continental one (Agrostio capillaris- Quercion petraeae Scamoni & H.Passarge 1959) and a very oceanic one, the Hymenopyllo tunbrigensis-Quercion roboris Je. Pall. 2000. The PVF1 Hyperico montani-Quercenion robori- petraeae Rameau 1996 nom. inval. is validated here, but as an alliance (Hyperico montani- Quercion petraeae Rameau ex all. nov.). Finally, the Lonicero periclymeni-Betuletalia pubescentis Willner & Mucina in Willner et al. 2016 is added, even if we lack data to propose any association. Key-words Querco roboris-Fagetea sylvaticae Braun-Blanq. & Vlieger in Vlieger 1937, Quercetalia roboris Tüxen 1931, Molinio caeruleae-Quercetalia roboris H. Passarge 1968, beech-oak forest, oak forest, acidophilous deciduous forests.