31 research outputs found
The role of Alnus glutinosa in the secondary succession on the abandoned meadows in the Piné Highland (Trentino, Italy).
No full textPatrons bryogéographiques dans les petites îles autour de la Péninsule italienne, de Sicile et Sardaigne.
No full textConsiderazioni briogeografiche mediante un’analisi bioclimatica lungo un tratto della Val d’Adige.
No full text
Dynamical tendencies in the vegetation of the Natural Reserve of Torricchio (Central Italy).
No full textRicerche ecologiche nelle riserve della Foresta Umbra (Gargano).
No full textSi descrivono le ricerche ecologiche botaniche condotte nelle riserve della Foresta Umbra (Gargano) nelle Riserve Pavari e Falascon
Estimates of trade-related adjustment costs in Syria
No full textThe scope and complexity of international trading arrangements in the Middle East, as well as their spotty historical record of success, underscores the urgent need for an adequate understanding of the relative costs and benefits of participation in preferential trading arrangements and, more generally, of changes in domestic import regimes. This paper seeks to address this problem by providing estimates of the adjustment costs associated with two broad classes of hypothetical trade policy scenarios for Syria: participation in preferential trading arrangements, and changes in the domestic import regime. The authors find that the revenue consequences of the first scenario may be substantial. Their analysis of the second scenario suggests that the number of tariff bands can be reduced, while ensuring revenue neutrality, via the introduction of a value added tax of sufficient but reasonable size.Trade Policy,Debt Markets,Free Trade,International Trade and Trade Rules,Economic Theory&Research
Evaluation of the italian apennine ecosystems with respect to anatomical and ethological characteristics of the roe deer
No full textPresent work aims to test the degree of suitability for the roe deer of the different Apennine habitats, relating to ecological and structural characteristics of the forest Apennine ecosystems (bioclimate, floristic structure and composition, food availability) with the specific anatomical characteristics of the digestive apparatus and alimentary habits of this ungulate. Although the roe deer is a ruminant, it must be considered a browsing animal that carefully selects what it ingests, choosing plants or plant parts rich in cellular sap of high protein content, and avoiding, as far as possible, plants with high content of raw fibre. Actual data seem to point out a range of suitability for the roe deer of the hilly and low-mountain wooded habitats, among which, nevertheless, remarkable differences in ecological and environmental level of suitability have been recorded. One of the principal limiting factors is the relationship between the availability of trophic resources present at the beginning of the autumn, and the length of the winter period. Also of notable importance are vegetation patches, types of forest management and the different floristic and structural characteristics of the ecotonal belts
Clonal growth modes in plant communities along a stress gradient in the Central Apennines, Italy.
No full textA simplification from species to functional groups using the concept of
clonality is particularly attractive for predictive modelling of vegetation processes and
preparing guidelines for nature conservation. This important functional trait based on a
modular structure including resource-acquiring units (ramets, feeding sites) and spacers,
has been studied in three plant communities (xeric grassland, mesic grassland, and beech
forest) under different levels of environmental stress (related to soil moisture and fertility)
in the Montagna di Torricchio Nature Reserve near Camerino, Central Apennines, Italy.
The study sought to reveal patterns of clonal growth modes (CGMs) in the three plant
community types, and to test a series of hypotheses on the importance of selected CGMs
along the stress gradient. Clonality was shown to have different importance in the
grassland communities, due to differences in the importance of various CGMs
(representing syndromes of clonal traits). Below-ground positioning of CGOs, shorter
spacers, higher multiplication potential, permanent physical connection between ramets,
large bud bank, and increased importance of bud protection were frequently found in
water-stressed xeric grasslands, suggesting the adaptive value of these clonal traits. The
major differences between grassland communities were due to the dominant CGMs: turf
graminoids (with an effective way of protecting growth meristems in dense tussocks)
dominated xeric grasslands, whereas rhizomatous graminoids (typical of competitive
resource-rich habitats) dominated mesic grasslands. The beech forest had fewer clonal
species (67%) and lower CGM diversity. Based on the assumption that different
environments promote different selection pressures, the tests revealed the following
results: (1) Plants with clonal organs below ground have significantly higher cover values
in stressed habitats. (2) Species with short spacers are more frequent in less favourable
environments, and their importance is almost ten times higher in the xeric grassland than in
the forest (71% to 7.6%). (3) The number of species able to produce numerous ramets is
highest in the most stressed habitat. (4) The number of species with a potential for longlasting
connection between ramets increases towards stressed environments. In contrast to
our expectations, the mesic grasslands (occupying the central position along the studied
stress gradient) have the highest number of species with storage organs. (6) In stressed
habitats, species with forms of bud protection were the most frequent
Dynamique des populations et mosaïque forestière en hêtraie-sapinière naturelle préservée. Une comparaison entre Vosges et Carpates
No full textA comparison of population dynamics and forest architecture has been carried in two well preserved beech-fir forests of Europe, in the Carpates and in the Vosges. The two reserves present marked differences in climate, soils and local environment. We show that beech dominates all the strata. In a situation of valley bottom (Carpates), its shady canopy explains growth patterns of understorey. Beech and fir present alternating phases of suppression and re-growth. Seedlings and saplings grow preferentially at the edges of adult canopies and in gaps. In the Vosges, slope induces imbricated crowns, and lateral light inputs are higher than in the Carpates. However regeneration is less dense because of less favourable soils and climate, and located preferentially in the neighbourhood of gaps. Both forests present a fine-grained architecture of eco-units, which increase resistance to disturbances.Une recherche comparative de sylvigénèse en hêtraie-sapinière a été entreprise dans deux réserves forestières intégrales, présentant des différences écologiques marquées dans les Hautes Vosges et les Carpates orientales. Les données recueillies concernent la structure des populations de ligneux (hêtre, sapin, épicéa, érable sycomore) et l’organisation architecturale des mosaiques forestières, par deux profils architecturaux, qui illustrent un aspect des situations sylvigénétiques rencontrées dans ces forêts de montagnes. Les principaux résultats démontrent que le hêtre domine les strates des deux forêts. En situation de fond de vallon (Carpates), l’ombrage qui résulte d’une canopée dense impose aux arbustes dominés (jeunes hêtres, mais surtout sapins) une croissance en palier parfois très longue, qui explique les situations préférentielles des semis en bordure des éco-unités matures ou dans les trouées. En situation de pente (Vosges), l’architecture en pile d’assiette des dominants, qui résulte de l’importance des apports lumineux latéraux, raccourcit cette attente. Mais les conditions plus rudes rencontrées dans cette réserve diminuent les densités à tous les étages. L’architecture des deux réserves montre une mosaïque fine d’ éco-unités à différentes hauteurs, composées de plusieurs espèces ligneuses atteignant parfois des dimensions impressionnantes. L’ensemble est très stable, en dépit des aléas climatiques.Schnitzler A., Closset-Kopp Deborah, Gafta D., Cristea Victoria, Schwoehrer C. Dynamique des populations et mosaïque forestière en hêtraie-sapinière naturelle préservée. Une comparaison entre Vosges et Carpates . In: Revue d'Écologie (La Terre et La Vie), tome 59, n°1-2, 2004. pp. 213-228
