Search results for "VEGETATION"
showing 10 items of 1069 documents
A multidisciplinary approach to reveal the Sicily Climate and Environment over the last 20 000 years
2010
Abstract We present a thorough review of the knowledge on the climate and environment in Sicily over the last 20 000 years, taking into account results of several studies carried using terrestrial and marine records. We obtain a coherent framework of the most important changes succeeded in the island, even if some points need further investigation. All the reconstructions of surface temperatures of the seas and the air surrounding Sicily point out severe climatic conditions during the last glacial period. The steppe- and semisteppe-like vegetation pattern testifies, together with additional evidence from geochemical data of lacustrine evidence, markedly arid conditions. Fi-nally, significan…
Habitat preference of endangered Eastern Iberian Reed BuntingsEmberiza schoeniclus witherbyi
2011
Capsule Careful management is required to maintain or create habitats with the correct proportions of rush with reeds that are preferred by this subspecies. Aims To determine the habitat requirements of Eastern Iberian (Western Iberian Reed Buntings were not included in the study) Reed Buntings Emberiza schoeniclus witherbyi, a subspecies endemic to a few marshes in France, Spain and Morocco, with a population of 254–360 breeding pairs. Methods Twenty-five wetlands in Spain were surveyed and presence/absence of Iberian Reed Buntings was deteremined together with data on 41 environmental variables. The relationships between the birds and habitat data were investigated using glm. Results Prop…
Temporal analysis of normalized difference vegetation index (NDVI) and land surface temperature (LST) parameters to detect changes in the Iberian lan…
2011
In past decades, the Iberian Peninsula has been shown to have suffered vegetation changes such as desertification and reforestation. Normalized difference vegetation index (NDVI) and land surface temperature (LST) parameters, estimated from data acquired by the Advanced Very High Resolution Radiometer (AVHRR) sensor onboard the National Oceanic and Atmospheric Administration (NOAA) satellite series, are particularly adapted to assess these changes. This work presents an application of the yearly land-cover dynamics (YLCD) methodology to analyse the behaviour of the vegetation, which consists of a combined multitemporal study of the NDVI and LST parameters on a yearly basis. Throughout the 1…
Esa's SMOS Mission – Supporting Agricultural Applications
2018
The European Space Agency's (ESA) SMOS mission, in orbit since more than 8 years, carries a passive microwave interferometric radiometer measuring in L-Band and provides accurate global observations of emitted radiation originating from the Earth's surfaces since the atmosphere is almost transparent in this spectral range. In addition, over land the effect of vegetation on the measurements is smaller than for shorter wavelengths. The scientific objectives of the SMOS mission directly respond to the need for global observations of soil moisture and ocean salinity, two key variables used in predictive hydrological, oceanographic and atmospheric models. SMOS observations also provide informati…
A view of the vegetation and economic exploitation of the forest in the Late Neolithic sites of Les Jovades and Niuet (Alicante, Spain)
1992
SummaryThe results of the charcoal analysis obtained in two open air sites of the Late Neolithic, although contrasting with what is known so far about their economy, as well as with the results of different palaeoamblental studies undertaken in other sites, mainly caves with long sequences, within the same area or in other near areas, form the main interest of this paper. We will begin presenting the data pertaining to both sites individually which, in the final part, will be assessed in order to reach a better understanding of the relationship between men and their natural environment during the Neolithic period.
Semi-natural Grassland Vegetation Database of Latvia
2012
The Semi-natural Grassland Vegetation Database of Latvia (GIVD ID EU-LV-001) was first developed in 1999 as part of the PhD Thesis on syntaxonomy and diversity of dry and mesic grasslands of Latvia. The database includes the original releves established by the author as early as 1997. The majority of releves belongs to the Filipendulo-Helictotrichion (Festuco-Brometea) and Arrhenatheretalia communities, but Molinietalia, Nardetalia, Caricion nigrae, Koelerion glaucae and Plantagini-Festucion are covered, as well. The total number of releves stored is 2,500 and there are approximately 700 releves to be digitised. Plot size varies from 1 to 125 m, the majority of releves are 4-9 m large. Rele…
Rapid recovery of invertebrate communities after ecological restoration of boreal mires
2015
Mire degradation due to drainage for forestry results in the loss of mire specialist species. To halt the loss in biodiversity, ecological restoration is needed and already implemented. However, a major challenge in ecological restoration is whether actions taken have the desired outcome. Key abiotic and biotic conditions for the successful restoration of invertebrate communities can be identified by testing the “Field of Dreams” hypothesis, which postulates that if a habitat is successfully restored, species will return. This study was conducted in nine boreal mires located in Eastern Finland, 1–3 years after restoration. Parts of each mire were drained for forestry during the 1960s and 19…
La reserva de semillas en una cuenca de "badlands" (Petrer, Alicante)
1992
In order to determine the influence of erosion in the absence of vegetation of badlands slopes, the seed content of the regolith and the seed removal by runoff in five storms were analyzed in an experimental catchment at Petrer (Alicante). Both, seed redistribution and seed loss were detected, but these seem to be insufficient to explain the lack of vegetation. It is hypothesized that besides the erosion process, factors such as pedoclimate, and chemical and physical properties of the regolith should be considered.
Zooplankton communities in doline lakes and pools, in relation to some bathymetric parameters and physical and chemical variables
1999
The zooplankton communities from several lakes and pools in three zones of a karstic area in central Spain were studied in spring and early autumn, in relation to morphometric, physical and chemical characteristics of the lakes. Zooplankton diversity was higher in autumn than in spring and it was positively correlated with lake size (area and depth) in spring, but not in early autumn. This effect is partially explained by the sharp zooplankton stratification in deep lakes, in early autumn. Some morphometric characteristics of lake basins were also correlated with the structure of zooplank- ton communities. Principal component analyses (PCA) and Two-Way Indicator Species Analysis (TWINSPAN) …
Changes in alpine snowbed-wetland vegetation over three decades in northern Norway
2013
We have quantified floristic changes in alpine snowbeds and wetland vegetation during three decades and analyzed to what extent these changes are related to initial variations in snow cover duration and distance to groundwater level. Vascular plant species richness and total plant cover were estimated along three transects in northern Norway. Three different vegetation zones were identified along the original transects: relatively dry snowbeds, wet snowbeds and wetlands. The resampling shows major changes in species richness and plant cover. In general, there was a net immigration of species and 13 new species were found. Five rare species with initial low cover were lost. In the dry and we…