1,721,012 research outputs found
A novel insight into the remnants of hygrophilous forests and scrubs of the Po Plain biogeographical transition area (Northern Italy)
Full text linkHygrophilous forests and scrubs are ecotonal habitats providing essential ecosystem services, especially in human-modified landscapes; nevertheless, they are among the most threatened habitats worldwide. A sound knowledge of waterside woody vegetation provides a valuable basis for interventions of renaturation of waterbodies. This paper focuses on peculiar communities that occur in riparian and swamp areas of the Po Plain, a broad ecotonal area between the Mediterranean and Temperate regions. The study allowed the description of six new associations. Moreover, it provides a detailed picture of Dioscoreo communis-Populetum nigrae (Populetalia albae) and Amorpho fruticosae-Salicetum albae (Salicetalia purpureae), an overview of Salicetum triandrae (Salicetalia purpureae) at the national and European level, and an update of the alliance Dioscoreo-Ulmion minoris, which is better characterized, classified in Populetalia albae and enlarged to include five associations of elm-oak-rich forests of the Po Plain lowlands and the Karst. Dioscoreo-Ulmion includes, besides Lamio orvalae-Ulmetum minoris, also Polygonato-Quercetum roboris and three new associations: Vinco minoris-Ulmetum minoris and Salvio glutinosae-Quercetum roboris from Po Plain rivers and the karstic lakeshore Rhamno catharticae-Ulmetum minoris. The new arrangement of Dioscoreo-Ulmion results from an analysis of Po Plain elm-rich forests including stands so far attributed to the critical alliance Alnion incanae; the presence of Querco-Ulmetum minoris in Italy is discussed. Two new associations are attributed to Prunetalia spinosae: Salici eleagni-Juniperetum communis and Ulmo minoris-Paliuretum spinae-christi. Stands from the Rivers Isonzo and Tagliamento referred to Veratro nigri-Fraxinetum excelsioris and to the new association Carici albae-Fraxinetum excelsioris represent the outermost expressions of the Ostryo-Tilion ravine forests extending towards the High Plain. A Salix alba swamp forest, Galio palustris-Salicetum albae, is reported for the first time in Italy and attributed to Alnetea glutinosae
The aquatic and wetland vegetation of Lake Doberdò: an analysis for conservation value assessment of a disappearing lake of the Classical Karst (North East Italy)
Full text linkLake Doberdò (Classical Karst) is a well-known example of karst lakes, temporary lakes that seasonally fill and empty through springs and swallow holes connected to the underground waters. It is an area of exceptional interest for geological-geomorphological and biodiversity conservation, and is part of the Natura 2000 network. Its peculiar hydro-ecological nature allows an impressive variety of species and habitats. A phytosociological survey was carried out to provide a comprehensive analysis of the vegetation. On the basis of 177 phytosociological relevés and multivariate analysis 43 communities were found, belonging to Platyhypnidio-Fontinalietea antipyreticae, Lemnetea minoris, Potametea pectinati, Bidentetea tripartitae, Isoëto-Nanojuncetea, Phragmito-Magnocaricetea, Agrostietea stoloniferae, Molinio-Arrhenatheretea, Filipendulo ulmariae-Convolvuletea sepium, Alnetea glutinosae, Rhamno catharticae-Prunetea spinosae, Alno glutinosae-Populetea albae. The Leucojo aestivi-Poetum pratensis association including waterside periodically flooded meadows is validated. Compared to the past, various communities show a change in their distribution while some valuable coenoses were not found. 21 communities are attributed to 8 Annex I Habitats of the 92/43/EEC Directive. The study confirms the high value of Lake Doberdò for biodiversity conservation but highlights an ongoing process of environmental change due to both natural and human-related causes including modifications of the hydrological regime and abandonment of traditional agricultural practices. An overview of the features of Lake Doberdò is provided to compare this disappearing lake with the karst groundwater-dependent wetlands found in Ireland called “turloughs”, corresponding to Annex I Habitat 3180*. Also on the basis of the current interpretation and distribution of this habitat type at the EU level, a proposal is presented to recognize and protect this outstanding area of the Natura 2000 network in Italy as the habitat 3180*, modelled on Irish turloughs
Approccio scientifico a una nuova cultura del paesaggio
No full textAllo scopo di tutelare l’ecomosaico paesaggistico l’Unione Europea ha messo a punto la nuova tipologia delle aree agricole ad Alto Valore Naturale (AVN). Nell’affrontare il problema dell’analisi del paesaggio vegetale ci siamo proposti di mettere a punto una “misurabilità scientifica” degli interventi sul territorio. A tal fine ci siamo avvalsi della fitosociologia dinamico-catenale (geosinfitosociologia), un approccio scientifico non percettivo-vedutistico, che mette in evidenza i rapporti temporali e spaziali delle unità di vegetazione (cenosi, associazioni) e che ha il merito di individuare in maniera oggettiva le unità ambientali e paesaggistiche.
L’area di studio comprende il bacino lacustre del Preval (Conca del Preval) e i colli che lo racchiudono, facenti parte del Collio goriziano, per una superficie di 17 chilometri quadrati. Nell’area sono stati eseguiti 90 rilievi con il metodo fitosociologico, è stato inoltre utilizzato materiale della banca dati della vegetazione del Friuli Venezia Giulia. Il tutto è stato integrato con le metodiche GIS. Al fine di valutare l’evoluzione storica dell’area di studio sono state realizzate le seguenti mappe tematiche: vegetazione potenziale, uso del suolo d’inizio ottocento, uso del suolo attuale, vegetazione reale attuale, maturità dell’ecosistema. Per valutare il grado di parcellizzazione del territorio è stato inoltre calcolato un indice di frammentazione. I risultati dimostrano che il territorio di studio rientrerebbe nelle aree agricole ad Alto Valore Naturale (AVN)
La vegetazione acquatica e palustre dell’Italia nord-orientale. 2 – La Classe Potametea Klika in Klika et V. Novák 1941
No full textViene descritta la vegetazione acquatica rizofitica riferibile alla classe Potametea nell'Italia nord-orientale. Complessivamente vengono riconosciute diciotto associazioni e dieci aggruppamenti, afferenti a quattro alleanze (Ranunculion fluitantis, Potamion, Ranunculion aquatilis, Nymphaeion albae) nell'ambito di un unico ordine (Potametalia). Due associazioni sono descritte come nuove: Potametum prolixi e Sparganio-Vallisnerietum spiralis. Per ciascuna comunità vengono riportate informazioni su composizione floristica, sintassonomia, sinfisionomia, sinecologia e sincorologia. L'analisi ha anche evidenziato la progressiva contrazione o scomparsa in molti dei tipi di maggior pregio a seguito dei porcessi di modificazione ambientale e di eutrofizzazione delle acque
Conservation of plant diversity of karst dry grasslands by the reintroduction of grazing. The case study of Basovizza/Bazovica in the Italian Karst
No full textFloristic and vegetation studies were conducted in an experimental area of the Italian Karst at Basovizza/Bazovica included in the Natura 2000 site “Carso Triestino e Goriziano” to assess the effects of the reintroduction of grazing on plant species and communities. In the area, partially deforested in 2006, cattle, sheep and goats were introduced in the summer of 2007. A monitoring programme for plant populations was performed focusing on four target species typical of the karst dry grasslands: Rock Knapweed Centaurea rupestris, Green-winged Orchid Orchis morio, Toothed Orchid Orchis tridentata and Mountain Pasqueflower Pulsatilla montana. Three exotic invasive species, detrimental to grazing, were also included: Tree of Heaven Ailanthus altissima, Narrow-leaved Ragwort Senecio inaequidens and Common Ragweed Ambrosia artemisiifolia. For each species, the GPS position was taken both for individuals and large groups of plants; a count of the individuals present at each measured point was performed too. In order to verify the process of re-colonization by species of calcareous dry grasslands, phytosociological relevés were carried out in areas previously occupied by Black Pine (Pinus nigra) plantations, woods with Downy Oak (Quercus pubescens) and Hop Hornbeam (Ostrya carpinifolia) and thermophilous scrub of Common Juniper (Juniperus communis), documented from vegetation maps made in 2005. For each vegetation type 6 permanent plots were selected, in which phytosociological relevés were carried out to. The study shows that in the areas of the original karst dry grassland more widely distributed species typical of the habitat remain. In overgrazed areas the grassy turf is discontinuous, segetal terophytic species of the class Stellarietea mediae entering into the gaps. Cover of the Musk Thistle (Carduus nutans) has increased significantly, as spiny species are not palatable to animals. The occasional presence of neophytes such as Daisy Fleabane (Erigeron annuus) and Canadian Horseweed (Conyza canadensis) was also found. In undergrazed areas, however, the natural processes of succession and scrubbing over are taking place. In the areas formerly occupied by pine plantations and woods with Quercus pubescens and Ostrya carpinifolia, Autumn Moor Grass (Sesleria autumnalis) and Rock Tor-grass (Brachypodium rupestre) are still able to become covered by a compact herbaceous sward. An abundant presence of Carduus nutans and the entry of Senecio inaequidens, the latter especially abundant on wood chips derived from tree clearing, were encountered as well as the spread of Ailanthus altissima favoured by the opening up of the scrubland
The technical and scientific management of the steppe grasslands of Italian and Slovenian Karst for the conservation of biodiversity and habitats
No full textThe aim of the research is to produce a syntaxonomical framework of Karst dry grasslands (habitat of Natura 2000 network) and provide cognitive tools that can be used for their restoration through good management practices. The methodological approach is based both on a definition of the optimum state of reference of flora and of vegetation (using phytosociological models) and on the association between phytosociological and agronomic information. The research was conducted in two steps: a. Update of taxonomic nomenclature and definition of a theoretical syntaxonomical reference framework; b. study of the relationships between the agronomic aspects and aspects of the flora and vegetation for meadows and pastures for specific sampling sites in the Italian and Slovenian Karst.
a. The unpublished (Poldini; Zanatta e schedis) and published relevés of the dry grasslands (class Festuco-Brometea, ordo Scorzonero-Chrysopogonetalia) of the Karst were classified along with similar but more thermophilic (alliance Chrysopogono grylli- Koelerion splendentis) and more mesophilic coenoses (class Molinio-Arrhenatheretea). The indicator species indices calculated for
associations have permitted the objective identification of groups of character and differential species for association. The distribution of dry grasslands in the Karst landscape is outlined and the taxonomic framework is updated via a nomenclatural and phytogeographical revision. The standard parameters (chorotype and life form spectrum) were calculated. The conservation value is defined by the calculation of standard indices of diversity.
b. This floristic-vegetation information represents the baseline for the assessment of changes in the vegetation and the status of the habitat. For each site phytosociological mrelevés were repeated in the years 2012- 13. In order to define their syntaxonomic affiliation, the collected data was compared with the phytosociological models. Almost all the sites fall within the Danthonio- Scorzoneretum. For each site the standard parameters are calculated, in order to assess the degree of deviation from the theoretical models and analyze the relationships between the community, management and productivity. The study highlights the trend towards a significant change in structure and function of the karst lands and the ,negative correlation between floristic richness and productivity. This raises the need to implement new strategies to bring the system moor towards the desired state
A diachronic approach to assess alien plant invasion: The case study of Friuli Venezia Giulia (NE Italy)
No full textDirect experimental methods for measuring plant invasiveness based on generative vs. vegetative reproductive mechanisms
have already been proposed in the literature. In the present work, an indirect method to measure plant species invasion using
historical and current data from various sources is described. This method involves a diachronic approach whereby the speed
of plant invasion can be measured as the rate of new site colonisation by species over time. The study was conducted in Friuli
Venezia Giulia (NE Italy). Field data, herbarium collections and data from the literature since the late 19th century were
used to gather information on the presence or absence of some alien species through time, and a simple index to measure the
invasion rate in the territory was developed. Results show that the diachronic approach allowed the identification of species
that are generally recognised as more invasive already in other studies
Flora e vegetazione terrestri
No full textCamminando con la scienza in tasca: Duino-Aurisina in un computer palmare. Botanic
Progetto di riqualificazione della Riserva naturale regionale dei Laghi di Doberdò e Pietrarossa
No full textLa Riserva dei Laghi di Doberdò e Pietrarossa, collocata nel Carso isontino e inclusa nella rete Natura 2000, comprende uno dei più importanti esempi di idrologia carsica presenti in Italia ed Europa. Gli elementi ambientali principali sono il Lago di Doberdò e la landa carsica, una prateria illirico-balcanica. In questo lavoro sono stati realizzati la carta della vegetazione del lago ottenuta mediante elaborazione di immagini SAPR (Sistemi Aeromobili a Pilotaggio Remoto), uno studio delle specie esotiche e l’analisi del grado di incespugliamento della landa. Questi ambienti sono gravemente minacciati dalla mancata gestione da parte dell'uomo: il lago è soggetto ad un naturale impaludamento soprattutto a causa del mancato controllo del canneto, mentre si evidenzia un elevato grado di incespugliamento nella landa come conseguenza dell'abbandono del pascolo. Ad aggravare la situazione è la diffusione di specie vegetali alloctone invasive. Per contrastare le tendenze in atto sono state individuate alcune linee di intervento
L' Asaro-Carpinetum betuli Lausi 64 del Carso nordadriatico
Full text linkThis paper describes in a more detailed way the Carpinus betulus wood - previously typified by its Author by means of a synthetic table - which grows on the North-oriented slopes of dolinas (sinkholes) and gives its subdivision in subassociations
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