Search results for "NEA"
showing 10 items of 16082 documents
New national and regional bryophyte records, 61
2019
New record of phytogeographical interest, at national or regional scale, for 47 bryophytes taxa are reported. New sites are located in 23 different geographical areas of . In particular, for each taxon, data on taxonomy, ecological as well as phytogeographical features are specified
Chlorophyll fluorescence as a tool for management of plant resources
1994
Abstract Light-induced chlorophyll fluorescence has become a tool which has ever-increasing potential application to experimental plant physiology. The effects of frost, heat, and drought have been analyzed using the kinetics of individual leaves of two representative types of life form: an evergreen tree (holm oak) dominant in the Mediterranean Basin and an annual cultivated legume (soybean). Various indices were used to quantify their response to environmental stress. Canopy fluorescence for the two types of plants was simulated. For two levels of measurement, leaf or canopy, light-induced fluorescence appears to be helpful for forest or crop management in the Mediterranean area.
Seagrass ecosystem response to long-term high CO2 in a Mediterranean volcanic vent
2014
We examined the long-term effect of naturally acidified water on a Cymodocea nodosa meadow growing at a shallow volcanic CO2 vent in Vulcano Island (Italy). Seagrass and adjacent unvegetated habitats growing at a low pH station (pH = 7.65 ± 0.02) were compared with corresponding habitats at a control station (pH = 8.01 ± 0.01). Density and biomass showed a clear decreasing trend at the low pH station and the below- to above-ground biomass ratio was more than 10 times lower compared to the control. C content and δ13C of leaves and epiphytes were significantly lower at the low pH station. Photosynthetic activity of C. nodosa was stimulated by low pH as seen by the significant increase in Chla…
Standardization proposal for the mapping of Caulerpa taxifolia expansion in the Mediterranean sea
1999
Fourteen years after the first observation of Caulerpa taxifolia (Valh) C. Agardh in the northwestern Mediterranean Sea, this green alga of tropical origin is now present in five countries (Spain, France, Monaco, Italy and Croatia). By the end of 1997, more than 46 km(2), at depths of between 0 and 50 m, were found to be affected by this expansion. A standardization of the cartographic procedure is proposed here. Such a standardization is necessary to compare maps produced by various organizations from different countries. For a given independent station, it is based on the definition of three levels of colonization:Level I refers to a station where one or several colonies less than 100 m a…
Different responses of coexisting Chara species to foreseeable Mediterranean temperature and salinity increases
2017
Abstract An increase in temperature of approximately 4 °C is expected to occur in the Mediterranean by the end of the century. Concomitant to this warming, a foreseeable rise in salinity will affect aquatic species. We addressed the effects of warming and salinity, and their interaction on three coexisting characean species (Chara aspera, C. hispida and C. vulgaris) from a Spanish Mediterranean interdunal pond (spring water temperature 20–23 °C, when charophytes re-grew; salinity 1.3–1.8 PSU). A laboratory experiment was designed with two levels of water temperature treatment (23 and 27 °C), plus two levels of salinity treatment (0.4 and 4.0 PSU). The variables considered were total length,…
Taxonomic remarks on Scilla anthericoides Poir. (Asparagaceae, Scilloideae), a neglected species from Algeria
2016
Scilla anthericoides is a neglected name traditionally considered as Urginea maritima var. anthericoides. Based on recent field observations of living plants completed by karyological analyses, we promote again this taxon at species rank, under the genus Charybdis. It differs from other species of Charybdis maritima aggregate by many characters of flowers, fruits, bulbs, leaves and by ploidy level. It is endemic to the regional hotspot Kabylias-Numidia-Kroumiria in north-eastern Algeria. It is a threatened species that has been assessed as vulnerable.
Tamarix arborea var. arborea and Tamarix parviflora: Two species valued for their adaptability to stress conditions.
2016
The choice of stress resistant and highly adaptable species is a fundamental step for landscaping and ornamental purposes in arid and coastal environments such as those in the Mediterranean basin. The genus Tamarix L. includes about 90 species with a high endurance of adversity. We investigated the water relations and photosynthetic response of Tamarix arborea (Sieb. ex Ehrenb.) Bge. var. arborea and T. parviflora DC. growing in an urban environment. Both species showed no evidence of drought or salt stress in summer, and appeared to follow two strategies with T. arborea var. arborea investing in high carbon gain at the beginning of the summer, and then reducing photosynthetic activity at t…
Establishing the occurrence and profile of polycyclic aromatic hydrocarbons in marine sediments: The eastern Mediterranean coast of Spain as a case s…
2019
Sampling, cost-effective analysis, diagnosis of sources of pollution and assessment of potential toxicological effects were included in the case study. Marine sediments collected from 24 points along the eastern Mediterranean coast of Spain (Comunitat Valenciana region) in 2010, 2011, 2012 and 2015 have been analysed for polycyclic aromatic hydrocarbons. Fluoranthene, pyrene, chrysene, benzo[b]fluoranthene and benzo[a]pyrene were the most found. An analysis of the relative abundance of selected PAHs revealed that petrogenic and mixed petrogenic/pyrogenic sources are predominant in the area. The total concentrations of the target compounds ranged from 14.7 to 615.3 ng/g dry weight. The effec…
Effects of global warming on reproduction and potential dispersal of Mediterranean Cnidarians
2019
Water temperature directly affects life cycles, reproductive periods, and metabolism of organisms living the oceans, especially in the surface zones. Due to the ocean warming, changes in water stratification and primary productivity are affecting trophic chains in sensitive world areas, such as the Mediterranean Sea. Benthic and pelagic cnidarians exhibit complex responses to climatic conditions. For example, the structure and phenology of the Mediterranean hydrozoan community displayed marked changes in species composition, bathymetric distribution, and reproductive timing over the last decades. The regional species pool remained stable in terms of species numbers but not in terms of speci…
Types of names of taxa belonging to theCentaurea cinerariagroup (Compositae) described from Sicily
2016
The group of Centaurea (sect. Acrolophus) cineraria (Compositae) in Sicily includes four currently accepted species plus four taxa that have been considered, with some doubt, as subspecies of one of them (C. panormitana). In total, discounting recombinations and replacement names, 11 names (seven specific, three varietal, one of a forma), all based on Sicilian material, were published by past authors for these eight taxa. Two of the names had their holotype indicated upon publication; two have been lectotypified previously; six (C. busambarensis var. obtusiloba, C. cineraria var. soluntina, C. cineraria var. umbrosa, C. todaroi, C. todaroi f. seguenzae and C. ucriae) are lectotypified here;…