Search results for " VEGETATION"

A syntaxonomical survey of the Sicilian dwarf shrub vegetation belonging to the class Rumici-Astragaletea siculi

2005

Basing on literature data and unpublished relevés from Sicily, a survey of the syntaxa belonging to the class Rumici-Astragaletea siculi Pignatti & Nimis 1980 em. Mucina 1997 (= Cerastio-Carlinetea nebrodensis Brullo 1984) is presented. The class groups orophilous plant communities dominated by dwarf- shrubs, often with a pulvinate and thorny growth form. The class is represented in Sicily by two orders: Rumici-Astragaletalia siculi Pignatti & Nimis 1980, including the sole alliance Rumici-Astragalion siculi Poli 1965, restricted to Mount Aetna, and Erysimo-Jurinetalia bocconei Brullo 1984, including two alliances: the acidophilous Armerion nebrodensis Brullo 1984 and the basiphilous Cerast…

Floristic survey of the former royal hunting reserve of Renda, near Palermo (Sicily, Italy)

2021

A mountainous area in western Sicily, where relic wood vegetation is still preserved notwithstanding past and present human pressure, is here analysed in order to prepare a checklist of its vascular flora. Field investigations allowed to compile a floristic inventory including 601 infrageneric taxa belonging to 304 genera and 80 families. Some remarks on the biological and chorological spectra are presented, and some measures to protect flora and vegetation are suggested, too.

Misión FLEX (Fluorescence Explorer): Observación de la fluorescencia por teledetección como nueva técnica de estudio del estado de la vegetación terr…

2014

[EN] FLEX (Fluorescence EXplorer) is a candidate for the 8th ESA’s Earth Explorer mission. Is the first space mission specifically designed for the estimation of vegetation fluorescence on a global scale. The mission is proposed to fly in tandem with the future ESA´s Sentinel-3 satellite. It is foreseen that the information obtained by Sentinel-3 will be supplemented with that provided by FLORIS (Fluorescence Imaging Spectrometer) onboard FLEX. FLORIS will measure the radiance between 500 and 800 nm with a bandwidth between 0.1 nm and 2 nm, providing images with a 150 km swath and 300 m pixel size. This information will allow a detailed monitoring of vegetation dynamics, by improving the me…

Global vegetation monitoring through multitemporal analysis of pathfinder AVHRR land database

2005

We have applied a Land Surface Temperature algorithm to the whole Pathfinder AVHRR Land (PAL) database, aiming at studying the evolution of the vegetation at a global scale. The Land Surface Temperature parameter, along with NDVI, will allow retrieving vegetation changes between July 1981 and September 2001. We have also built a classification which takes into account both vegetation variations and thermal patterns, from NDVI and Air Temperature at 2 meters height data. This classification allows differentiating areas which present close vegetation changes throughout the year, but totally different climates, as for example in mountainous and semiarid regions. The main quality of this classi…

Vegetation of rock clefts and ledges in the Pamir Alai Mts, Tajikistan (Middle Asia)

2014

AbstractThe paper presents the results of phytosociological research conducted on the vegetation of rock clefts and ledges in the Pamir-Alai Mountains (Tajikistan, Middle Asia). During the field studies, done in 2010–2012, 101 phytosociological relevés were taken. Plant species were recorded according to the Braun-Blanquet cover-abundance scale. Communities of calcareous rock clefts and ledges with small soil amounts from several ranges (Zeravshan Mts, Hissar Mts, Hazratishokh Mts, Darvaz Mts, Rushan Mts and Vanch Mts), inhabiting mainly the alpine and subnival zone, have been described. A synopsis of the rock communities of the Pamir-Alai is proposed. In the examined vegetation plots 77 va…

NDVI seasonal amplitude and its variability

2008

NDVI (Normalized Difference Vegetation Index) is a remotely sensed index of vegetation greenness. Its yearly cycle gives information on vegetation type or health, and monitoring its temporal evolut...

2015

In this study we present a hyperspectral flying goniometer system, based on a rotary-wing unmanned aerial vehicle (UAV) equipped with a spectrometer mounted on an active gimbal. We show that this approach may be used to collect multiangular hyperspectral data over vegetated environments. The pointing and positioning accuracy are assessed using structure from motion and vary from σ = 1° to 8° in pointing and σ = 0.7 to 0.8 m in positioning. We use a wheat dataset to investigate the influence of angular effects on the NDVI, TCARI and REIP vegetation indices. Angular effects caused significant variations on the indices: NDVI = 0.83–0.95; TCARI = 0.04–0.116; REIP = 729–735 nm. Our analysis high…

Turbulent mixing and dispersion mechanisms over flexible and dense vegetation

2019

The present study investigates flow turbulence and dispersion processes in the presence of flexible and dense vegetation on the bed. The turbulent dispersion coefficients and the terms of the turbulent kinetic energy equation are determined by using data collected in a straight laboratory channel with living vegetation on the bed. Results show that the turbulent integral lengths assume an order of magnitude comparable to the stems’ characteristic dimension independently by the direction and the turbulence assumes an isotropic behavior. The coefficients of dispersion have a trend similar to that of the turbulent lengths and assume low values in the longitudinal, transversal and vertical dire…

The Braun-Blanquet project: evaluating and characterizing European vegetation alliances

2014

European tradition on vegetation classification provides an extraordinary legacy for understanding biodiversity. However, this classification lacks explicit data on vegetation attributes, especially if we extend national or regional concepts to a continental perspective. An additional effort for evaluating and characterizing European vegetation types is therefore needed, and the data contained in vegeta­ tion databases are probably the main tool for these purposes. The Braun­Blanquet project is an initiative of the European Vegetation Survey for characterizing veg­ etation alliances across Europe. By analyzing more than 500,000 vegetation plots from 22 European countries, we developed a fra…

Classifying plant communities and mapping their potential distribution using very large, heterogeneous, georeferenced datasets: the case study of the…

2014

In recent years, the scientific community has made significant efforts in order to create geo­referenced vegetation databases (Global Index of Vegetation Plot Databases). These databases are useful to carry out assessments of the state of bio­ diversity, conservation of species and habitats, dispersion of alien species and as a support for the planning of land and protected areas. In this context, Italy has given birth to its own project called VegItaly, coordinated by the Italian Society of Vegetation Science and conducted by several research groups, in order to develop a uniform database for the entire country. Within this framework we have created a georeferenced database of phytosociolo…