Search results for "VEGETATION"
showing 10 items of 1069 documents
Phytolith analyses from Khil and Kaf Taht el-Ghar (Western Maghreb): Plant use trajectories in a long-term perspective
2021
In this paper we present the results of phytolith investigations at two archaeological sites in northwestern Morocco: Khil (Tangier) and Kaf Taht el-Ghar (Tétouan). The two sites located in Western Maghreb, one on the Atlantic and one on the Mediterranean coast, were investigated in the framework of the AGRIWESTMED project. Phytolith analysis complemented archaeobotanical, geoarchaeological and archaeological investigations to better identify plant use during the entire occupation sequence. At Khil 16 samples have been studied, coming from two profiles excavated in two different caves of the same system – grotte B and grotte C – that span a chronology comprised between the early Neolithic a…
Late Holocene Aleppo pine (Pinus halepensis Miller) woodlands in Mallorca (Balearic Islands, Western Mediterranean): Investigation of their distribut…
2021
The pioneering nature of Mediterranean pines and their phytosociological role have been largely discussed in relation to different agents (e.g., edaphic, climatic or anthropogenic). In this context, Aleppo pine is one of the most widespread pine species in the Mediterranean basin, as it is especially adapted to climatic constraints, such as drought and high seasonality, and has a high tolerance for salinity and strong coastal winds. It is also well adapted to regeneration after anthropogenic landscape disturbances, highlighting its important after-fire regeneration rates. In this sense, phytosociological studies conducted in Mediterranean landscapes have found that this species' wide distri…
Holocene environmental and climatic changes at Gorgo Basso, a coastal lake in southern Sicily, Italy
2009
Abstract We used a new sedimentary record to reconstruct the Holocene vegetation and fire history of Gorgo Basso, a coastal lake in south-western Sicily (Italy). Pollen and charcoal data suggest a fire-prone open grassland near the site until ca 10,000 cal yr BP (8050 cal BC), when Pistacia shrubland expanded and fire activity declined, probably in response to increased moisture availability. Evergreen Olea europaea woods expanded ca 8400 to decline abruptly at 8200 cal yr BP, when climatic conditions became drier at other sites in the Mediterranean region. Around 7000 cal yr BP evergreen broadleaved forests ( Quercus ilex , Quercus suber and O. europaea ) expanded at the cost of open commu…
Start of the dry season as a main determinant of inter-annual Mediterranean forest production variations
2014
Abstract Recent investigations have highlighted the dependence of Mediterranean forest production on spring rainfall. The current work introduces the concept of the start of the dry season (SDS) and performs a three-step analysis to determine the effect of SDS on Mediterranean forest production. Seven forest zones of Tuscany (Central Italy), which present differently pronounced Mediterranean features, are considered. First, a statistical analysis investigates the influence of spring water budget on forest Normalized Difference Vegetation Index (NDVI) inter-annual variations during July–August. The analysis is then extended to assess the impact of inter-annual SDS variability on forest gross…
Is seed availability enough to ensure colonization success?
2006
Abstract We tested the hypothesis that seed availability is a limiting factor for plant colonization of road embankments under Mediterranean climate conditions. Experimental sowing on 10 road embankments was carried out to compare the colonization success of plants that successfully colonize the road embankment and species that appear only occasionally in the road embankments. After sowing, we measured plant establishment, biomass production, and reproductive capacity of the species. The species that appear only occasionally in the road embankments had lower emergence rates (l.l ± 0.3%) than species that were successful colonizers (18.8 ± 2.9%). None of the species of the former group survi…
Trying to link vegetation units with biomass data: the case study of Italian shrublands
2014
Although their carbon stock is relevant in assessing the baseline for the negotiation of future agreements with respect to carbon balance, there still are few available studies concerning the biomass and the net ecosystem exchange capacity of Mediterranean shrublands. In this chapter a preliminary overview on the biomass values concerning Italian shrubland communities and/or their dominant/ characteristic woody species is provided. Many useful data on above- and belowground biomass issued from investigations carried out in other Mediterranean countries and concerning plant communities, which share the same ecological, floristic and structural traits of Italian shrublands. A preliminary find…
One Chara does not make Charetea in the Mediterranean aquatic vegetation
2019
The results of preliminary phytosociological investigations on freshwater communities of Sicily biotopes with a significant presence of Characeae are presented. In spite of the relatively frequent occurrence of Characeae, a typical Charetea intermediae vegetation is rather rare in the investigated biotopes. Indeed, the Characeae are mainly part of communities attributable to the classes Potamogetonetea, Phragmito-Magnocaricetea, Juncetea maritimi and Isoeto-Nanojuncetea. Some ecological and functional implications are discussed, along with some consequences on conservation measures and policies, caused by the lack of knowledge on the Characeae of Sicily.
L-Band radiative properties of vine vegetation at the MELBEX III SMOS Cal/Val Site
2012
Radiative properties at 1.4 GHz of vine vegetation are investigated by measuring brightness temperatures with the ETH L-band Radiometer II (ELBARA II) operated on a tower at the Mediterranean Ecosystem L-band Characterisation Experiment III (MELBEX III) field site in Spain. To this aim, experiments with and without a reflecting foil placed under the vines were performed for the vegetation winter and summer states, respectively, to provide prevailingly information on vegetation transmissivities. The resulting parameters, which can be considered as "ground truth" for the MELBEX III vineyard, were retrieved from brightness temperature at horizontal and vertical polarization measured at observa…
Emerging contaminants related to the occurrence of forest fires in the Spanish Mediterranean
2017
Forest fires can be a source of contamination because, among others, of the use of chemicals to their extinction (flame retardants, FRs), or by the production of Polycyclic Aromatic Hydrocarbons (PAHs) derived from high temperature alteration of organic matter. Up to our knowledge, this study is the first to assess the direct (PAHs 16 on the USA EPA's priority list), and indirect [tri- to hepta- brominated diphenyl ethers (PBDEs), organophosphorus flame retardants (PFRs) and perfluoroalkyl substances (PFASs)] contamination related to forest fires. The abundance and distribution of these contaminants were monitored on two Mediterranean hillslopes, one burned and one unburned, near Azuébar (S…
The impact of Pinus halepensis mill. afforestation on mediterranean spontaneous vegetation: do soil treatment and canopy cover matter?
2012
We investigated central Mediterranean Pinus halepensis plantations under semi-arid climate in order to evaluate the combined effect of soil treatment and afforestation practices on spontaneous plant species composition, richness and evenness, and on the trend and speed of vegetation dynamics. Phytosociological releves of three different plot typologies, i.e. (1) soil-treatment and plantation, (2) only soil-treatment, (3) no soil-treatment and no plantation, were compared by (a) multivariate analysis and (b) with reference to species richness and evenness. Moreover, in order to compare vegetation dynamics within the plantations with those ones ongoing in semi-natural garrigue communities, we…