Search results for " VEGETATION"
showing 10 items of 435 documents
Experimental investigation on the role of vegetation on sediment transport mechanism: review of recent results
2012
Germination Pattern of Chamaerops humilis Seed after Short-Time Storage
2015
Dwarf fan palm (Chamaerops humilis) plays an important ecological role in the thermo Mediterranean vegetation stage, both in woodlands, xerophitic shrub communities and degraded ecosystems. Dwarf fan palm is typically propagated from seeds. Whereas other palm species show reduced germination after few months of seed storage, no information is available on the effects of storage time on seed germinability . We examined the germination pattern of dwarf palm seeds aged after a storage of four, six or eight months in comparison to fresh seed (control). A covariance analysis was performed to test the effect of time within seed-storage treatment. The germination patterns were significantly fitted…
Verità e menzogna dei simboli
2008
Cosa sono e come funzionano i simboli? Quali sono i meccanismi di trasmissione dell’immaginario, i suoi spazi e la sua rilevanza sociale? Quali il ruolo e il perimetro del sacro, del mito, del rito, della magia e della religione in certi ambiti, erroneamente percepiti come marginali, della società contemporanea? Quali le strategie di trasmissione della memoria culturale e i processi di produzione e riproduzione dell’identità comunitaria? I saggi riuniti in questo volume cercano di fornire alcune risposte a questi interrogativi confrontandosi con la pervasiva, sebbene non di rado occulta, dialettica culturale tra immanenza e trascendenza e indagando sulle dinamiche psicologiche e sociali del…
The ecology of the cork-oark (Quercus suber L.) stands in NW Sicily
2017
The uneven presence of the cork oak (Quercus suber L.) within its distribution range seems to be affected not only by its climatic requirements but also by rather specific edaphic needs. In fact, most of the known populations throughout the Mediterranean area thrive on acidic soils deriving from metamorphic or volcanic rock outcrops. However, some Italian populations of this species behave as if they were independent on the chemical and physical characteristics of the substrate, e.g. growing on calcareous soils, which are considered less suitable. This is the case of some populations in central Italy (Latium) and NW Sicily (Trapani Mts. and Palermo Mts.). A multidisciplinary investigation c…
Mapping soil water content under sparse vegetation and changeable sky conditions: comparison of two thermal inertia approaches
2013
A critical analysis of a thermal inertia approach to map surface soil water content on bare and sparsely vegetated soils by means of remotely sensed data is reported. The study area is an experimental field located in Barrax, Spain. In situ data were acquired within the Barrax 2011 research project. An advanced hyperspectral scanner airborne imager provides images in the visible/near-infrared and thermal infrared bands. Images were acquired both in day and night times by the Instituto Nacional de Técnica Aeroespacial between 12th and 13th of June 2011. The scene covers a corn irrigation pivot surrounded by bare soil, where a set of in situ data have been collected both previously and simult…
Probabilistic and preferential sampling approaches offer integrated perspectives of Italian forest diversity
2023
Aim: Assessing the performances of different sampling approaches for documenting community diversity may help to identify optimal sampling efforts and strategies, and to enhance conservation and monitoring planning. Here, we used two data sets based on probabilistic and preferential sampling schemes of Italian forest vegetation to analyze the multifaceted performances of the two approaches across three major forest types at a large scale. Location: Italy. Methods: We pooled 804 probabilistic and 16,259 preferential forest plots as samples of vascular plant diversity across the country. We balanced the two data sets in terms of sizes, plot size, geographical position, and vegetation types. F…
Impact of Structural, Photochemical and Instrumental Effects on Leaf and Canopy Reflectance Variability in the 500–600 nm Range
2021
Current rapid technological improvement in optical radiometric instrumentation provides an opportunity to develop innovative measurements protocols where the remote quantification of the plant physiological status can be determined with higher accuracy. In this study, the leaf and canopy reflectance variability in the PRI spectral region (i.e., 500–600 nm) is quantified using different laboratory protocols that consider both instrumental and experimental set-up aspects, as well as canopy structural effects and vegetation photoprotection dynamics. First, we studied how an incorrect characterization of the at-target incoming radiance translated into an erroneous vegetation reflectance spectru…
Particle tracking in a gap of aquatic vegetation meadow
2009
Aquatic vegetation considerably affects the flow field in water bodies, with influence increasing as the depth decreases. As a consequence, vegetation also affects suspended particle transport. In inshore sandy beds less than 40 m deep of the Mediterranean Sea, meadows of Posidonia oceanica are widespread. This plant is constituted by a tuft of very thin and flexible ribbon-like leaves about 1 cm wide and up to 1.5 m long; the meadow areal density can reach 1000-1200 plant/m2. Frequently, such meadows are not continuous but vegetated areas alternate with sand strips (“gaps”). The presence of such discontinuities noticeably affects the flow field and gaps can actually act as particle traps. …
Implementation of IUCN criteria for the definition of the Red List of Ecosystems in Italy, Plant Biosystems.
2020
The present work is aimed at presenting the data, methods and criteria that are being used for the assessment of ecosystem collapse risk in Italy.