241 research outputs found

    Bioclimatology, structure, and conservation perspectives of Quercus pyrenaica, Acer opalus subsp. Granatensis, and Corylus avellana deciduous forests on Mediterranean bioclimate in the South-Central part of the Iberian Peninsula

    Get PDF
    The plant variability in the southern Iberian Peninsula consists of around 3500 different taxa due to its high bioclimatic, geographic, and geological diversity. The deciduous forests in the southern Iberian Peninsula are located in regions with topographies and specific bioclimatic conditions that allow for the survival of taxa that are typical of cooler and wetter bioclimatic regions and therefore represent the relict evidence of colder and more humid paleoclimatic conditions. The floristic composition of 421 samples of deciduous forests in the south-central part of the Iberian Peninsula were analyzed. The ecological importance index (IVI) was calculated, where the most important tree species were Quercuspyrenaica, Aceropalus subsp. Granatensis, and Corylusavellana. These species are uncommon in the south-central part of the Iberian Peninsula, forming forests of little extension. An analysis of the vertical distribution of the species (stratum) shows that the majority of the species of stratum 3 (hemicriptophics, camephytes, geophites, and nanophanerophytes) are characteristic of deciduous forests, and their presence is positively correlated with high values of bioclimatic variables related to humidity and presence of water in the soil (nemoral environments), while they are negatively correlated with high values of bioclimatic variables related to high temperatures, evapotranspiration, and aridity. This work demonstrates that several characteristic deciduous forest taxa are more vulnerable to disappearance due to the loss of their nemoral conditions caused by gaps in the tree or shrub canopy. These gaps lead to an increase in evapotranspiration, excess insolation, and a consequent loss of water and humidity in the microclimatic conditions.info:eu-repo/semantics/publishedVersio

    Expansion of the Juniperus Genus due to Anthropic Activity

    Get PDF
    This work contains a study of Juniperus forests in the southern Iberian Peninsula and aims to determine their floristic composition and their biogeographical, ecological and bioclimatological distribution. The analysis of Juniperus formations revealed a series of different plant communities. The presence of endemic companions in these plant communities justifies the study of these islands: Echinospartum ibericum Rivas Mart., Sánchez Mata & Sancho, Adenocarpus argyrophyllus (Rivas Goday) Caball., Digitalis purpurea L. subsp. mariana (Boiss.) Rivas Goday, Sideritis lacaitae Font Quer, Coincya longirostra (Boiss) Greuter & Burdet, Cytisus scoparius (L.) Link subsp. bourgaei (Boiss.) Riv.-Mart., Cytisus striatus (Hill) Rothm. subsp. eriocarpus (autor), Genista polyanthos R. Roem. Ex Willk., Dianthus crassipes R. de Roemer, Dianthus lusitanus Brot. Digitalis thapsi L., Digitalis purpurea L. subsp. Heywoodii P. Silva & M. Silva, subsp. mariana (Boiss) Rivas Goday, Securinega tinctoria (L.) Rothm., Lavandula stoechas L. subsp. luisieri (Rozeira) Rozeira, lavandula stoechas subsp. sampaiana Rozeira, Genista hirsuta Vahl, Thymus mastichina (L.) L., Thymus grantensis Boiss. subps. micranthus (Willk.) O. Boòs & Vigo, Thymus zygis Loefl ex L. subsp. gracillis (Boiss.) Boiss., Antirrhinum graniticum Roth. subsp. onubensis (Fernández Casas) Valdés. The territories in the study are of community interest (SCI) due to the presence of habitats such as Habitat 8220, which includes the plant associations Digitali thapsi-Dianthetum lusitani Rivas-Martínez ex Fuente 1986, Jasiono marianae-Dianthetum lusitani Rivas Goday (1955) 1964, Coincyo longirostraae-Dianthetum lusitani Melendo in Cano, Melendo & F. Valle 1997, and is the motive for the need to conserve these areas. However the dominant species in these environments is Juniperus oxycedrus L. subsp. lagunae (Pau ex C. Vicioso) Rivas Mart., and all the other –mainly endemic– species are located within its vicinity. These zones can thus be classified as hotspots with particular interest for conservation. Areas dominated by Juniperus are currently becoming more widespread due to the greater prevalence of rock beds, which increase every year in response to deforestation and forest fires. This phenomenon leads to the extension of edaphoxerophilous zones and a decrease in climatophilous zones, and creates more potential areas that can potentially act as a refuge for endemic species

    Current Concepts in the Treatment of Retinitis Pigmentosa

    Get PDF
    Inherited retinal degenerations, including retinitis pigmentosa (RP) and Leber congenital amaurosis (LCA), affect 1 in 4000 individuals in the general population. A majority of the genes which are mutated in these conditions are expressed in either photoreceptors or the retinal pigment epithelium (RPE). There is considerable variation in the clinical severity of these conditions; the most severe being autosomal recessive LCA, a heterogeneous retinal degenerative disease and the commonest cause of congenital blindness in children. Here, we discuss all the potential treatments that are now available for retinal degeneration. A number of therapeutic avenues are being explored based on our knowledge of the pathophysiology of retinal degeneration derived from research on animal models, including: gene therapy, antiapoptosis agents, neurotrophic factors, and dietary supplementation. Technological advances in retinal implant devices continue to provide the promise of vision for patients with end-stage disease

    Competition between alien and native species in xerothermic steno-Mediterranean grasslands: Cenchrus setaceus and Hyparrhenia hirta in Sicily and southern Italy

    Get PDF
    Perennial dry grassland communities, vital for plant biodiversity conservation in the Mediterranean, often harbor rare and endangered species. However, these habitats face threats, including the invasion of alien species. Cenchrus setaceus, a highly invasive grass, is spreading in the Mediterranean region. Historical records and observations document its establishment and invasiveness across various Italian regions. This study investigates the impact of C. setaceus on native grasslands dominated by Hyparrhenia hirta. We assessed the impact of C. setaceus invasion on plant biodiversity in Sicily and southern Italy, and we identified and characterized plant species’ composition using Ellenberg indicator values. The intention to analyze species richness, diversity, and ecological indicators is also emphasized. Starting from the use of the phytosociological method, multivariate analysis and Ellenberg indicator values to assess the impact of C. setaceus on grasslands composition were considered. There are several similarities and differences in diversity, floristic composition, and ecological traits between the two grassland types. A deep comparison with central European studies and evaluation of the impact of C. setaceus on species richness and community dynamics in Mediterranean habitats were concluded. Although C. setaceus is invading native grasslands, it does not drastically reduce species richness. The ecological implications of the invasion are explored, urging ongoing monitoring and collaborative efforts for effective conservation. The importance of interdisciplinary cooperation is highlighted to address the threat of invasive species and sustain the biodiversity of Mediterranean grasslands

    The assessment and the within-plant variation of the morpho-physiological traits and VOCs profile in endemic and rare Salvia ceratophylloides Ard. (Lamiaceae)

    Get PDF
    Salvia ceratophylloides (Ard.) is an endemic and rare plant species recently rediscovered as very few individuals at two different Southern Italy sites. The study of within-plant variation is fundamental to understand the plant adaptation to the local conditions, especially in rare species, and consequently to preserve plant biodiversity. Here, we reported the variation of the morpho-ecophysiological and metabolic traits between the sessile and petiolate leaf of S. ceratophylloides plants at two different sites for understanding the adaptation strategies for surviving in these habitats. The S. ceratophylloides individuals exhibited different net photosynthetic rate, maximum quantum yield, light intensity for the saturation of the photosynthetic machinery, stomatal conductance, transpiration rate, leaf area, fractal dimension, and some volatile organic compounds (VOCs) between the different leaf types. This within-plant morpho-physiological and metabolic variation was dependent on the site. These results provide empirical evidence of sharply within-plant variation of the morpho-physiological traits and VOCs profiles in S. ceratophylloides, explaining the adaptation to the local conditions

    Impact of grass cover management with herbicides on biodiversity, soil cover and humidity in olive groves in the Southern Iberian

    Get PDF
    In the present work, we studied the effect of herbicide use on extensive olive grove cultivation. To carry out this study, we analysed the effect that herbicide use had on biodiversity, vegetation cover and soil water content. For this purpose, 96 vegetation and soil sampling points were first taken, then georeferenced, and for each sampling point, several bioclimatic variables were interpolated. We concluded that the management of cover crops with herbicides over a long period of time resulted in a decrease in biodiversity, and the dominance of some species that were more resistant to herbicides was increased. Another finding was that the vegetation cover was reduced in the resampling in cases with herbicide management and that the location within the cropland (under the tree canopy, road, boundary or pasture) also has an influence. Finally, the study of soil moisture shows that soil water content was lower in the case of management with herbicides than in the case of management without herbicides. This loss of soil moisture was more accentuated and faster in areas with less vegetation cover. This work highlights the need to change the management models for tree crops in order to preserve biodiversity, soil quality and optimise water resources in a context of accelerated climate change in one of the regions most severely affected by global warming, the Mediterranean belt.info:eu-repo/semantics/publishedVersio

    Indicative value of the dominant plant species for a rapid evaluation of the nutritional value of soils

    Get PDF
    A study was conducted on 14 grassland communities located in the south of the Iberian Peninsula and their edaphology, which is identified as specific plant associations. The edaphic study of each association allows a rapid evaluation of the nutrient content in the soil without the need for laboratory edaphic analysis. For each phytosociological relevé and soil, samplings were carried out. The field data were subjected to various statistical analysis—canonical correspondence analysis (CCA), Bayesian networks, and decision trees—to establish nutrient content. When the abundance value of the species is 9 in the Van der Maarel scale, there is an increase in the values of several soil parameters. In the case of Hordeum leporinum, when the Van der Maarel index is 9, the Kc (exchangeable potassium in cmol/kg) undergoes the greatest variation, to a value of up to 0.729 cmol/kg. The application of the decision tree to this species reveals that the soil attributes with the greatest influence in the classification are conductivity, %_si (silt texture), pH, and pF 15 atm (pressure at 15 atmospheres (water retention capacity) in %). Indeed, this interlaced edaphic and phytosociological study provides us with a high-value tool to obtain quick information on the content of nutrients in the soil.info:eu-repo/semantics/publishedVersio

    Global and Regional IUCN Red List Assessments: 9

    Get PDF
    In this contribution, the conservation status assessment of three vascular plants according to IUCN categories and criteria are presented. It includes the assessment of Soldanella calabrella Kress at global level, and the regional assessment of Luzula pindica (Hausskn.) Chrtek & Křísa and Romulea variicolor Mifsud (Italy)
    corecore