Search results for " VEGETATION"
showing 10 items of 435 documents
On the relationship between some production parameters and a vegetation index in viticulture
2013
The use and timing of many agronomical practices such as the scheduling of irrigation and harvesting are dependent on accurate vineyard sampling of qualitative and productive parameters. Crop forecasting also depends on the representativeness of vineyard samples during the whole phenological period. This manuscript summarizes the last two years of precision viticulture in Sicily (Italy); agronomic campaigns were carried out in 2012 and 2013 within the "Tenute Rapitalà" and "Donnafugata" farms. Normalized Difference Vegetation Index derived from satellite images (RapidEye) acquired at berry set, pre-veraison and ripening phenological stages (occurred at June, July and August respectively) ha…
Habitat area and local habitat conditions outweigh fragmentation effects on insect communities in vineyards
2022
Fragmentation of habitat, for example by intensive agricultural practices, can be detrimental to local biodiversity. However, it often remains unclear whether such biodiversity declines are caused by loss of habitat area or increased fragmentation, and how habitat quality factors into it. In our study system, vegetated vineyards are typically small, and isolated from one another, potentially limiting the distribution and dispersal of organisms. In a full-factorial experiment of a priori selected vegetated vineyard patches of differing size and fragmentation, we aimed to disentangle the effects of habitat area (area of vegetated vineyards), habitat fragmentation (number of vegetated vineyard…
Experimental investigation of flow turbulent structure in a high-amplitude vegetated meandering laboratory flume
2018
The present work focuses on high-curved channels which are characterized by a complex flow turbulent structure. The specific aim of work is to analyze the evolution of turbulent coherent motion in the pres-ence of vegetation on the bed.
Disjunct populations of European vascular plant species keep the same climatic niches
2015
Aim Previous research on how climatic niches vary across species ranges has focused on a limited number of species, mostly invasive, and has not, to date, been very conclusive. Here we assess the d ...
Timing and patterns of the ENSO signal in Africa over the last 30 years: insights from normalized difference vegetation index data.
2014
Abstract A more complete picture of the timing and patterns of the ENSO signal during the seasonal cycle for the whole of Africa over the three last decades is provided using the normalized difference vegetation index (NDVI). Indeed, NDVI has a higher spatial resolution and is more frequently updated than in situ climate databases, and highlights the impact of ENSO on vegetation dynamics as a combined result of ENSO on rainfall, solar radiation, and temperature. The month-by-month NDVI–Niño-3.4 correlation patterns evolve as follows. From July to September, negative correlations are observed over the Sahel, the Gulf of Guinea coast, and regions from the northern Democratic Republic of Congo…
Benchmarking plant diversity of Palaearctic grasslands and other open habitats
2021
© 2021 The Authors.
Trend Analysis of Global MODIS-Terra Vegetation Indices and Land Surface Temperature Between 2000 and 2011
2013
Previous works have shown that the combination of vegetation indices with land surface temperature (LST) improves the analysis of vegetation changes. Here, global MODIS-Terra monthly data from 2000 to 2011 were downloaded and organized into LST, NDVI (Normalized Difference Vegetation Index) and EVI (Enhanced Vegetation Index) time series. These time series were then corrected from cloud and atmospheric residual contamination through the IDR (iterative Interpolation for Data Reconstruction) method. Then, statistics were retrieved from both corrected time series, and the YLCD (Yearly Land Cover Dynamics) approach has been applied to data sources (NDVI-LST and EVI-LST) to analyze changes in th…
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.
Facebook groups as citizen science tools for plant species monitoring
2021
I social network sono canali di comunicazione utilizzati per condividere enormi quantità di dati, che possono essere utilizzati per la ricerca scientifica, anche nel campo della biodiversità. Per sapere quanto i dati ricavati dai social network possono integrare quelli raccolti per scopi scientifici, è necessario individuarne i bias. Utilizzando i dati estratti da un gruppo Facebook specializzato nella flora vascolare siciliana, abbiamo analizzato quali sono i caratteri che aumentano la probabilità che una pianta spontanea venga fotografata e postata su un social network. A tal fine, abbiamo confrontato frequenze e attributi delle specie fotografate dai membri del gruppo Facebook con quelli…
Remote sensing of sunlight-induced chlorophyll fluorescence and reflectance of Scots pine in the boreal forest during spring recovery
2005
A measurement campaign to assess the feasibility of remote sensing of sunlight-induced chlorophyll fluorescence (ChlF) from a coniferous canopy was conducted in a boreal forest study site (Finland). A Passive Multi-wavelength Fluorescence Detector (PMFD) sensor, developed in the LURE laboratory, was used to obtain simultaneous measurements of ChlF in the oxygen absorption bands, at 687 and 760 nm, and a reflectance index, the PRI (Physiological Reflectance Index), for a month during spring recovery. When these data were compared with active fluorescence measurements performed on needles they revealed the same trend. During sunny days fluorescence and reflectance signals were found to be str…