Search results for " POSIDONIA OCEANICA"
showing 10 items of 49 documents
Tecnica di reimpianto mediante griglie metalliche
2014
Selezione di aree per il reimpianto di Posidonia oceanica mediante modello multicriteriale ed impianti pilota
2014
Analisi dei pattern di distribuzione di Posidonia oceanica lungo gradienti batimetrici
2011
Assessing Seagrass Restoration Actions through a Micro-Bathymetry Survey Approach (Italy, Mediterranean Sea)
2022
Underwater photogrammetry provides a means of generating high-resolution products such as dense point clouds, 3D models, and orthomosaics with centimetric scale resolutions. Underwater photogrammetric models can be used to monitor the growth and expansion of benthic communities, including the assessment of the conservation status of seagrass beds and their change over time (time lapse micro-bathymetry) with OBIA classifications (Object-Based Image Analysis). However, one of the most complex aspects of underwater photogrammetry is the accuracy of the 3D models for both the horizontal and vertical components used to estimate the surfaces and volumes of biomass. In this study, a photogrammetry…
Adhesive root hairs facilitate Posidonia oceanica seedling settlement on rocky substrates
2015
Posidonia oceanica, the dominant Mediterranean seagrass, has been historically described as a species typically growing on mobile substrates whose development requires precursor communities. During more than 10 years of direct observations, we noticed that P. oceanica seedlings were often firmly anchored to rocky reefs, even at exposed sites. Thus, we analysed the ultrastructural features of seedling root systems to identify specific traits that may represent adaptations for early seedling anchorage on rocky bottoms. Subapical sections of adventitious roots were obtained from 2-3 months old specimens collected in the field and were observed at SEM revealing an extensive coverage of adhesive…
REUTILIZACIÓN DE RESIDUOS DE PODA DE VID Y DE POSIDONIA OCEANICA EN LAS OBRAS DE BIOINGENIERÍA DEL PAISAJE
La popolazione mondiale è in continua espansione e la crescita demografica ed economica inducono allo sfruttamento progressivo dell’ambiente ed al depauperamento delle risorse naturali (acqua ed energia in particolare), con conseguenti impatti potenzialmente importanti sul cambiamento globale. Si rende, pertanto, necessaria ed urgente una più efficiente gestione delle risorse basata sulla rielaborazione di obiettivi sostenibili di politiche e strategie ambientali e sulla riduzione del consumo delle risorse, promuovendo la transizione da un modello di economia lineare ad uno circolare, costituito da un ciclo continuo di sviluppo positivo che preserva e migliora il capitale naturale, ottimizz…
Climate change and Mediterranean seagrass meadows: a synopsis for environmental managers
2014
12 páginas, 3 figuras
Evidences of adaptive traits to rocky substrates undermine paradigm of habitat preference of the Mediterranean seagrass Posidonia oceanica
2015
AbstractPosidonia oceanica meadows are acknowledged as one of the most valuable ecosystems of the Mediterranean Sea. P. oceanica has been historically described as a species typically growing on mobile substrates whose development requires precursor communities. Here we document for the first time the extensive presence of sticky hairs covering P. oceanica seedling roots. Adhesive root hairs allow the seedlings to firmly anchor to rocky substrates with anchorage strength values up to 5.23 N, regardless of the presence of algal cover and to colonise bare rock without the need for precursor assemblages to facilitate settlement. Adhesive root hairs are a morphological trait common on plants li…
Shoot age as a confounding factor on detecting the effect of human-induced disturbance on Posidonia oceanica growth performance
2007
Abstract The response of orthotropic rhizome elongation and primary production of Posidonia oceanica to anthropogenic perturbations and potential confounding effects of shoot age were assessed using a Linear Multilevel Model (LMM). This model examined the confounding effect of age by comparing the estimates of impact and variance components obtained by excluding and including Age as an explanatory variable. Age had a negative effect on rhizome elongation and primary production with an annual decrease of 0.6 mm y − 1 and 7 mg dw y − 1 respectively. According to the LMM when age effect was omitted, the differences between disturbed and control locations in rhizome elongation and primary produ…
Analisi della prateria a Posidonia oceanica (L.) Delile (Najadales, Potamogetonaceae)dell’Area Marina Protetta “Isola di Ustica” (Sicilia nord-occide…
2009
Vengono presentati i risultati di uno studio sul posidonieto dell’Area Marina protetta “Isola di Ustica” (Sicilia nord-occidentale), comprendente l’analisi lepidocronologica, fenologica e il censimento della flora epifita delle foglie e dei rizomi di Posidonia oceanica (L.) Delile (Najadales,Potamogetonaceae). Le osservazioni e i campionamenti sono stati effettuati in nove stazioni distribuite lungo tre transetti. I risultati ottenuti mostrano che attualmente la prateria è complessivamente in una situazione di equilibrio. Ciò indica buone condizioni ambientali anche se non ottimali per la fioritura della pianta dato che come risulta dall’analisi lepidocronologica e dalle osservazioni dirett…