Search results for " VEGETATION"

Accelerated Changes of Environmental Conditions on the Tibetan Plateau Caused by Climate Change

2011

Abstract Variations of land surface parameters over the Tibetan Plateau have great importance on local energy and water cycles, the Asian monsoon, and climate change studies. In this paper, the NOAA/NASA Pathfinder Advanced Very High Resolution Radiometer (AVHRR) Land (PAL) dataset is used to retrieve the land surface temperature (LST), the normalized difference vegetation index (NDVI), and albedo, from 1982 to 2000. Simultaneously, meteorological parameters and land surface heat fluxes are acquired from the 40-yr European Centre for Medium-Range Weather Forecasts (ECMWF) Re-Analysis (ERA-40) dataset and the Global Land Data Assimilation System (GLDAS), respectively. Results show that from …

Landsat TM/ETM+ and tree-ring based assessment of spatiotemporal patterns of the autumnal moth (Epirrita autumnata) in northernmost Fennoscandia

2010

Abstract We used fine-spatial resolution remotely sensed data combined with tree-ring parameters in order to assess and reconstruct disturbances in mountain birch ( Betula pubescens ) forests caused by Epirrita autumnata (autumnal moth). Research was conducted in the area of Lake Tornetrask in northern Sweden where we utilized five proxy parameters to detect insect outbreak events over the 19th and 20th centuries. Digital change detection was applied on three pairs of multi-temporal NDVI images from Landsat TM/ETM+ to detect significant reductions in the photosynthetic activity of forested areas during disturbed growing seasons. An image segmentation gap-fill procedure was developed in orde…

Proposals for improvement of Annex I of Directive 92/43/ EEC: Central Italy

2021

The main purpose of the 92/43/EEC Habitats Directive is to contribute to the conservation of biodiversity, understood as habitat types and species of the flora and fauna of the European Union. To achieve this goal, natural and semi-natural biodiversity as a whole must be recognized and included in its annexes. As for the conservation of biotopes, named habitat types, Italy is unfortunately lacking as it the Annex I does not include important ecosystems that are typical of its territory, rare for biogeographical reasons or threatened. Therefore, the opportunity to identify a first list of significant habitats for central Italy is discussed here. For each of the new proposed types (new habita…

“Harvesting memories”: Integrated approaches of human ecology and landscape archaeology in rural Sicily, the case of Castro Valley and Mt. Barraù (Co…

2016

The “Harvesting Memories” project focuses on the study of the long-term transformation of the historical landscape in a rural area of Central-Western Sicily (Castro Valley and Mt. Barraù, Corleone – Palermo). In order to achieve a global comprehension of the landscape, which we consider to be a diachronic result of the interaction between humans and their surrounding environment, our main research threads focus on socio-historical and environmental transformation. To this end we are applying an holistic approach, resulting from the cross-pollination of different methodologies: 1) Archaeological research: field survey and pottery studies allow the reconstruction of the historical settlement …

High variability of edge effects on forest vegetation diversity

2012

National audience; The influence of edges on vegetation diversity in forest fragments is an important issue for biodiversity conservation because of the large part of temperate woodlands concerned. In numerous empirical studies, a general pattern has been identified; it is described as two zones: the edge where plant distribution is linked to the distance from the forest border, the core area where the variability of vegetation is not linked to this distance. We present results of a study aiming at measuring the edge effects on vegetation in forest fragments in south-western France and at identifying potential factors of their variability. Vegetation was sampled in 28 transects constituted …

THE 60th IAVS ANNUAL SYMPOSIUM. Vegetation patterns in natural and cultural landscapes

2017

Monitoring barley and corn growth from remote sensing data at field scale

2004

Vegetation indices have been used for operational quantitative monitoring of vegetation. Here, corn and barley cultures have been used to relate meaningful biophysical parameters such as dry biomass and Crop Growth Rate (CGR) to the well-established Normalized Difference Vegetation Index (NDVI). We explain these relationships by means of the use of the Light Use Efficiency (LUE) models, based on the positive relation between primary production and Absorbed Photosynthetically Active Radiation (APAR). In these models we introduce NDVI as a linear estimator of f APAR. Experimental data over corn and barley show that dry biomass is linearly related to the Time-Integrated Value of the NDVI (TIND…

Global Scale IB AMSR2 Vegetation Optical Depth at X-Band

2021

Vegetation Optical Depth (VOD) plays an increasingly important role in studying global carbon, water and energy transformation [1], [2]. This study explores the performance of the X-MEB (X-band microwave emission of the biosphere) model at global scale. Similar to the L-MEB model, the X-MEB model, built by INRAE (Institut national de recherche pour l'agriculture, l'alimentation et l'environnement) Bordeaux, aims to retrieve VOD (referred to as IB X-VOD) at X-band. To avoid the ill-posed problem caused by retrieving two parameters of interest (soil moisture (SM) and VOD) from mono-angular and dual-polarized observations (AMSR2), which are strongly correlated, we used the ERA5 SM product as a…

Distribution patterns, floristic structure and habitat requirements of the alpine river plant community Stuckenietum amblyphyllae ass. nova (Potamete…

2012

This paper discusses the floristic structure, distribution and habitat requirements of a new aquatic syntaxon, <em>Stuckenietum a</em><em>m</em><em>b</em><em>l</em><em>y</em><em>p</em><em>h</em><em>ylla</em><em>e </em>ass. nova. Patches of the <em>Stuckenietum amblyphyllae </em>association occur in the Pamir Alai Mountains in Middle Asia (Tajikistan). The biotope of this community represent high mountain rivers and ponds at the bottom of glacial river valleys situ- ated at elevations between 1900 and 3800 m. Patches of the <em>Stuckenietum amblyphyllae </em>ass…

Distribution, floristic structure and habitat requirements of the riparian forest community Populetum talassicae ass. nova in the Central Pamir-Alai …

2013

This paper discusses the floristic structure, distribution and habitat requirements of a new forest syntaxon, <em>Populetum talassicae </em>ass. nova. The potential range of the <em>Populetum talassicae </em>association comprises the central Pamir-Alai and Tian-Shan Mountains in Middle Asia. The biotope of this community comprises high mountain river valleys and shore zones of mountain lakes situ- ated at elevations between 2200 and 2750 m. Phytocoenoses of the <em>Populetum talassicae </em>association are characterized by a clear predominance in the tree layer of a characteristic species of the association ‒ <em>Populus talassica</em>. Shrubs…