Global and Regional IUCN Red List Assessments: 5

In this contribution, the conservation status of four vascular plants according to IUCN categories and criteria are presented. It includes the assessment of Arceuthobium oxycedri (DC.) M.Bieb., Ionopsidium albiflorum Durieu, Trifolium latinum Sebast., and Vicia incisa M.Bieb. at a Regional level (Italy)

Coenological shift following fertilization in a Mediterranean grassland.

In Rome both meadows of CentraI-European affinity and Mediterranean dry grasslands are presento We studied a site (Parco Regionale Urbano de] Pineto in Rome) with very diverse vegetation, where species belonging to both coenologica] groups oceur. Wc fertilized a grassland with a combination of phosphorus (P) and nitrogen (N). After fertilization diagDostie species of Helianthemetea guttati (Thcrophytes) dccrease while species of MolinioArrhenatheretea (Hemicriptophytes) increase. In a climate as that of Rome, transition between Mediterranean (with summer drought) and Central European (without summer drought), nutrients availability modulates the distribution of vegetation Classes with respectively Mediterranean or Central-Europe affinities

COENOLOGICAL SHIFT FOLLOWING FERTILIZATION IN MEDITERRANEAN GRASSLAND

In Rome both meadows of CentraI-European affinity and Mediterranean dry grasslands are presento We studied a site (Parco Regionale Urbano de] Pineto in Rome) with very diverse vegetation, where species belonging to both coenologica] groups oceur. Wc fertilized a grassland with a combination of phosphorus (P) and nitrogen (N). After fertilization diagDostie species of Helianthemetea guttati (Thcrophytes) dccrease while species of MolinioArrhenatheretea (Hemicriptophytes) increase. In a climate as that of Rome, transition between Mediterranean (with summer drought) and Central European (without summer drought), nutrients availability modulates the distribution of vegetation Classes with respectively Mediterranean or Central-Europe affinities

THE ALLIANCE TRACHYNION DISTACHYAE RIVAS-MARTINEZ 1978 IN CENTRAL ITALYIN CENTRAL ITALY

The therophytic basiphilous vegetation of Central Italy has been generally framed in a single association Trifolio scabri- Hypochoeridetum achyrophori Biondi et al. 1997. We show that a considerable floristic variation exists inside Trifolio-Hypochoeridetum in Central Italy, and that it should be treated as a complex of no less than five different associations: Medicagini rigidulae-Trifolietum scabri Fanelli et al. hoc loco, Trifolio scabri-Hypochoeridetum achyrophori Biondi, Izco. Ballelli & Formica 1997 s.s, Hippocrepido siliquosae- Brachypodietum distachyi Fanelli et al. ad interim, Trigonello gladiatae-Brachypodietum distachyi Fanelli et al. hoc loc, Crucianello latifoliae-Hypochoeridetum achyrophori Filesi, Blasi, Di Marzio 1996. These associations are floristically and ecologically distinct, and show different geographical ranges in Central Italy. The great diversity of Trachynion distachyae in Central Italy is related to the widespread occurrence of limestone and calcareous alluvial rocks and to a climate with abundant winter and autumn rains very favourable to the development of winter annuals

Vegetation ecology of Castelporziano woodlands

In the present work the results of a three-year ecological study carried out in 11 forest sites of the CP Estate, are discussed. Three different data set, ecological-floristic, edaphic and microclimatic, have been collected through phytosiological relèves, soil profiles and microclimatic measurements. The Ellenberg model (1974) has been applied to the floristic matrix to obtain for each community indicator values for light, temperature, continentality, soil moisture, soil reaction and soil nutrients. A statistical treatment of data showed several significant correlations between ecological indicators of species and communities and variables of soil and microclimate measured in the field. In particular, a strong relationship between soil moisture indicator value and Available Water Capacity measured in the soils (AWC) has been found. Microclimatic data focus on a remarkable heterogeneity of the Castelporziano woodlands, showing different seasonal trends as well as different critical periods during the year. In particular, different associations can be ordered according to a gradient of a few correlated parameters: temperature, yearly thermic excursion, air moisture. The seasonal trend of different microclimatic parameters varies along this gradient, and it seems that not average values but seasonal variaton is the key factor in structuring vegetation. Microclimatic parameters are also correlated with chemical soil parameters: for instance, high soil temperature correlated with high soil water capacity increases microbial activity and consequently influences the cycles of nitrogen, carbon and phosphorus. The whole of the correlations suggests the strenght of the interactions existing between plant communities and environmental measured variables, indicating a rather coherence of the ecological processes in the forest habitat of the CP Estate

AVAILABLE SOIL WATER CAPACITY AS A DISCRIMINANT FACTOR IN MIXED OAK FOREST OF CENTRAL ITALY

Soil water content is a critical factor in Mediterranean forest vegetation, especially in areas subjected to prolonged summer drought where winter and autumn rainfall are the main sources of water. Available soil water capacity (AWC) is the maximum amount of water available for plants that a soil could possibly contain. Each soil has a specific available water capacity, however, most of the published literature on AWC refers 10 agricultural settings, although the interaction between the soil and the vegetation dynamics has long been recognized. The aim of this study was to investigate whether this edaphic factor could be discriminant in species assemblage of communities belonging to the thermophylous oak forest (order Quercetalia pubescentis). Thirty-two vegetation relevés and soil profiles were carried out in five different sites, with a similar pluvio-thermic regime, located in the sub-coastal belt of Latium, Central Italy. From the physical-chemical analyses of soil profiles, the AWC values, of the related relevés, were calculated. Multivariate statistical analysis was applied to the vegetation surveys, using Cluster Analysis from which a classification in three different clusters was obtained; subsequently the AWC values were grouped according to the c1assification obtained. Analysis of variance was used to test similarity and the output pointed out a significant difference among the three clusters (F=6.35;

AVAILABLE SOIL WATER CAPACITY AS A DISCRIMINANT FACTOR IN MIXED OAK FOREST OF CENTRAL ITALY

Soil water content is a critical factor in Mediterranean forest vegetation, especially in areas subjected to prolonged summer drought where winter and autumn rainfall are the main sources of water. Available soil water capacity (AWC) is the maximum amount of water available for plants that a soil could possibly contain. Each soil has a specific available water capacity, however, most of the published literature on AWC refers 10 agricultural settings, although the interaction between the soil and the vegetation dynamics has long been recognized. The aim of this study was to investigate whether this edaphic factor could be discriminant in species assemblage of communities belonging to the thermophylous oak forest (order Quercetalia pubescentis). Thirty-two vegetation relevés and soil profiles were carried out in five different sites, with a similar pluvio-thermic regime, located in the sub-coastal belt of Latium, Central Italy. From the physical\-chemical analyses of soil profiles, the AWC values, of the related relevés, were calculated. Multivariate statistical analysis was applied to the vegetation surveys, using Cluster Analysis from which a classification in three different clusters was obtained; subsequently the AWC values were grouped according to the c1assification obtained. Analysis of variance was used to test similarity and the output pointed out a significant difference among the three clusters (F=6.35;