The analysis of the vegetation and the landscape of the Simbruini mountains is presented. The Simbruini mountains are located on the Tyrrhenian side of the Central Apennines, on the border between the Lazio and Abruzzi regions; the mountain chain has a NW-SE orientation and is characterised by several peaks: Autore (1853 m), Cotento (2014 m), Tarino (1959), Viglio (2176 m) and Crepacuore (1997 m). The paper is composed of three sections. In the first one, the phytosociological and synphytosociological analysis of the vegetation is presented. In the second one, the results of an ecological classification of the landscape, aimed at identifying the main land units of the Simbruini mountains, are discussed and in the last one the landscape changes occurred between 1950 and 2000 are analysed.
From a phytosociological point of view, beech woods are the most important and wider forest type of the area. Their floristic composition is typical of the calcicolous Central-Southern Apennine mountain beech woods (Cardamino kitaibelii-Fagetum sylvaticae). At lower altitudes, deciduous woods dominated by Ostrya carpinifolia with Fraxinus ornus and Acer opalus ssp. obtusatum (Melittio melissophyllae-Ostryetum carpinifoliae), or by Quercus pubescens (Cytiso sessilifolii-Quercetum pubescentis) occur, whereas at the same altitudes, on the rocky or steep slopes, Quercus ilex woods can be found. Mesophilous woods with Carpinus betulus and Corylus avellana (Carpino betuli-Coryletum avellanae) were found along deeply embanked valleys, sometimes surrounded by Quercus cerris woods with Acer opalus ssp. obtusatum (Aceri obtusati-Quercetum cerridis) on deep soils. Along the Simbrivio river banks, small patches of broadleaf ravine woods, classified in the alliance Tilio-Acerion (Aceretum obtusati-pseudoplatani), can be found. The shrub vegetation is characterised by different communities dynamically linked to the woody types. In fact, shrubs characterised by Spartium junceum and Rubus ulmifolius (Spartio juncei–Cytisetum sessilifolii and Roso sempervirenti-Rubetum ulmifolii) were identified in the hilly-sub-mountain belt, whereas at higher latitudes, the pre-forest stage, characterised by Ribes uva-crispa and several species of Rosa (Ribeso uvae-crispae-Rosetum dumalis) can be found. Two kinds of juniper shrubs were identified: the first one in the sub-alpine belt with Daphne oleoides and Arctostaphylos uva-ursi (Daphno oleoidis-Juniperetum alpinae), and the second one with Juniperus communis ssp. communis in the lower mountain belt (Viburno lantanae-Juniperetum communis). The following grassland types were identified: three associations of the mountain and sub-mountain belts belonging to the endemic Apennine syntaxonomical alliance Phleo ambigui-Bromion erecti (Saturejo montanae-Brometum erecti, Anthoxantho odorati-Brachypodietum genuensis and Koelerio splendentis-Brometum erecti), therophytic grasslands (Trifolio scabri-Hypochoeridetum achyrophori), mesophilous meadows of the Molinio-Arrhenatheretea class (Colchico lusitanici-Cynosuretum cristati community with Arrhenatherium elatius), sub-alpine xerophytic grasslands with Sesleria juncifolia ssp. juncifolia and Carex kitaibeliana (Pediculari elegantis- Seslerietum tenuifoliae), sub-acid communities of the same belt belonging to the Nardetea strictae (Luzulo italicae-Nardetum strictae and Trifolio thalii-Festucetum microphyllae) and scree vegetation characterised by Galium magellense and Festuca dimorpha (Galio magellensis-Festucetum dimorphae). Moreover, two associations of the chasmophytic vegetation and calcareous rocky crevices were found (Saxifrago australis-Trisetetum bertolonii and Arenario bertolonii-Cystopteridetum alpinae). The vegetation of the woody edges was also analysed (community with Salvia glutinosa and Aegopodium podagraria), although further investigations are needed.
The synphytosociological analysis of the plant communities allowed the identification of the main vegetation series: Cytiso-Querceto pubescentis sigmetum, Ciclamino Hederifolii-Querceto ilicis sigmetum, Melittio melissophyllae-Ostryeto carpinifoliae sigmetum, Cardamino kitaibelii-Fageto sylvaticae sigmetum, Carpino betuli-Coryleto avellanae sigmetum and Daphno-Junipereto alpinae sigmetum.
In the second section of the paper, an ecological classification of the landscape aimed at identifying the main land units of Simbruini mountains was applied, based on a new methodology. In particular, a maximum likelihoods classifier, applied to topographical, climatic and land use variables, allowed the identification of 8 Land Units characterised by environmental, vegetational and land use variables.
Finally, the landscape change of the Simbruini mountains between 1950 and 2000 was analysed. This change was analysed and quantified through the photointepretation of digital, georeferenced aero photographs of the years 1954 and 2000 and application of several landscape indexes. A significant expansion of forests common to all the Apennine chain was highlighted. This process, linked to the abandonment of the traditional selvicoltural practices, in turn, determined by the emigration of the population, in search of economic opportunities, towards the coastal areas,. The current reforestation processes can determine the homogeneity of the landscape and the disappearance of semi-natural and cultural habitats, thus threatening the survival of many species.
The integrated methodological approach we presented, being based on the phytosociological and synphytosociological analysis, the ecological classification of the landscape and the analysis of its historical transformations, provides a comprehensive analysis useful for guiding environmental planning activities and for implementing conservation strategies and actions.