Search results for " VEGETATION"
showing 10 items of 435 documents
Characterizing land condition variability in Ferlo, Senegal (2001–2009) using multi-temporal 1-km Apparent Green Cover (AGC) SPOT Vegetation data
2011
Abstract The ecosystem state or ‘land condition’ can be characterized by a set of attributes, which show variations at different temporal scales. A multi-resolution analysis (MRA) based on the wavelet transform (WT) has been implemented to examine the land condition of a dryland region in Ferlo (Senegal) over the period 2001–2009. This methodology has proven to be useful for smoothing time series while considering those temporal resolutions that incorporate information about the vegetation dynamics. For this purpose, time series of the 1-km Apparent Green Cover (AGC) from the 10-day composites SPOT Vegetation (VGT) data are analyzed. Two relevant outputs from the MRA, A 1 (de-noised) and th…
Brown and green LAI mapping through spectral indices
2015
Abstract When crops senescence, leaves remain until they fall off or are harvested. Hence, leaf area index (LAI) stays high even when chlorophyll content degrades to zero. Current LAI approaches from remote sensing techniques are not optimized for estimating LAI of senescent vegetation. In this paper a two-step approach has been proposed to realize simultaneous LAI mapping over green and senescent croplands. The first step separates green from brown LAI by means of a newly proposed index, ‘Green Brown Vegetation Index (GBVI)’. This index exploits two shortwave infrared (SWIR) spectral bands centred at 2100 and 2000 nm, which fall right in the dry matter absorption regions, thereby providing…
Multitemporal analysis of PAL images for the study of land cover dynamics in South America
2006
Pathfinder AVHHR Land (PAL) database has been used for the retrieval of Land Surface Temperature (LST) over South America, which, along with NDVI parameter, will allow the studying of the evolution of the vegetation between July 1981 and September 2001. To this end, a classification has been built, based on PAL NDVI and Reanalysis air temperature at 2 m height data. This classification takes into account both vegetation and thermal patterns, and has been validated by a comparison with CAZALAC's map of arid zones (Centro del Agua para Zonas Aridas y semiaridas de Latino-America y el Caribe), as well as with Global Land Cover Characteristics' classification built by the USGS (United States Ge…
Spatial genetic structure reveals migration directionality in Mediterranean Ruppia spiralis (Western Sicily)
2022
Mediterranean salinas, originally built for salt production, function as alternative wetlands. A variety of accompanying lagoon, ditch, and marsh systems are suitable habitats for salt-tolerant submerged macrophytes and often characterized by monospecific beds of Ruppia. Traditionally, birds are considered the main dispersal vector of submerged macrophytes. However, Ruppia spiralis habitats are under marine influence and therefore interference of coastal currents in their connectivity might be expected. In this study, we aim to infer connectivity and spatial patterns from population genetic structures. Using nuclear microsatellite loci, the nuclear ribosomal cistron and chloroplast sequence…
Alnus glutinosa Riparian Woodlands of Italy and Corsica: Phytosociological Classification and Floristic Diversity
2022
A comparative analysis of the riparian vegetation dominated by Alnus glutinosa in Italy and Tyrrhenian islands, based on literature data and unpublished relevés, is presented. A total of 456 phytosociological relevés were processed. For the definition of plant communities and alliances, hierarchical clustering was performed by using Bray-Curtis coefficient and Detrended Correspondence Analysis ordination methods. Identification of diagnostic species of the vegetation units was performed by means of the phi fidelity index. Quantum GIS software version 3.6 was used for the interpolation of the bioclimatic variables and A. glutinosa communities. Overall, a total of 18 A. glutinos…
Warming trends in Patagonian subantartic forest
2019
Abstract The forests in the Aysen region (ca. 43–49 °S, Chile) have a high degree of wilderness and cover more than 4.8 million hectares, making it one of the largest areas of subantarctic forest in the Southern Hemisphere. The impact of global warming on this region is poorly documented. The main objective of this work was to analyze the normalized difference vegetation index (NDVI), land surface temperature (LST) and precipitation over Aysen forests in the context of ongoing global warming. We used average monthly images of LST and NDVI derived from the MODIS sensor covering the period 2001–2016 and precipitation from gridded datasets. The Aysen region was divided into three nested spatia…
GrassPlot v. 2.00 : first update on the database of multi-scale plant diversity in Palaearctic grasslands
2019
Abstract: GrassPlot is a collaborative vegetation-plot database organised by the Eurasian Dry Grassland Group (EDGG) and listed in the Global Index of Vegetation-Plot Databases (GIVD ID EU-00-003). Following a previous Long Database Report (Dengler et al. 2018, Phyto- coenologia 48, 331–347), we provide here the first update on content and functionality of GrassPlot. The current version (GrassPlot v. 2.00) contains a total of 190,673 plots of different grain sizes across 28,171 independent plots, with 4,654 nested-plot series including at least four grain sizes. The database has improved its content as well as its functionality, including addition and harmonization of header data (land use,…
Contributo alla conoscenza della vegetazione forestale dell’Egeo.
2004
Nell'ambito di ricerche fitosociologiche nell'area egea vengono presentati i risultati relativi alle formazioni forestali attualmente osservabili nelle isole dell'Egeo meridionale. Questo tipo di vegetazione è stato in precedenza oggetto di studio da parte di vari autori, fra cui in particolare Krause et al. (1963), Zohary & Orshan (1966), Barbero & Quezel (1980), Costa et al. (1984) e Géhu et al. (1989, 1990, 1992), che hanno esaminato sotto il profilo fitosociologico alcune isole dell'Egeo quali Eubea, Creta, Rodi e Karpatos. Allo scopo di ampliare le conoscenze su quest'area del Mediterraneo, ancora poco nota dal punto di vista vegetazionale, sono state effettuate indagini su numerose is…
Urban Services to Ecosystems - Green Infrastructure Benefits from the Landscape to the Urban Scale
2021
The aim of this book is to bring together multidisciplinary research in the field of green infrastructure design, construction and ecology. The main core of the volume is constituted by contributions dealing with green infrastructure, vegetation science, nature-based solutions and sustainable urban development. The green infrastructure and its ecosystem services, indeed, are gaining space in both political agendas and academic research. However, the attention is focused on the services that nature is giving for free to and for human health and survival. What if we start to see things from another perspective? Our actions shall converge for instance to turn man-made environment like cities f…
The SISV support to the implementation of a national manual for monitoring the Habitats of the 92/43/EEC Directive in Italy.
2016
The 4th National Report ex Art. 17 of the 92/43/EEC Directive in Italy (period 2013-2018) will try to fill a number of gaps still affecting the former versions of the Italian Reports, where territorial data were still missing for large parts of the country and the assessment was mostly based on the use of the expert opinion. Similar inconsistencies also emerged in other European countries (State of nature in the EU, EEA 2015). In order to reach this aim, a nationally shared protocol for monitoring the vegetation-based Annex I Habitats is currently under development. The most prominent issues addressed by the ongoing project are: i) fixing standardized, updated and scientifically grounded me…