Chine ; Climat ; Géographie physique ; Haut plateau ; Himalaya ; Montagne ; Plateau ; Régionalisation ; Tibet ; Végétation ; Zonage de la végétation ; Zonation altitudinale ; Zonation latitudinale
Zonage de la végétation du plateau tibétain. Caractère de haut-plateau de la végétation tibétaine. Circulation atmosphérique, indices climatiques. Description de 7 grandes zones de végétation. Caractère phytogéographique spécifique du haut-plateau
Satellite-derived vegetation indices applied to semi-arid shrublands in Australia
Australie ; Couverture végétale ; Domaine semi-aride ; Indice de végétation ; LANDSAT ; New South Wales ; Thematic Mapper ; Télédétection ; Végétation
Australia ; LANDSAT ; New South Wales ; Plant cover ; Remote sensing ; Semi-arid area ; Thematic Mapper ; Vegetation ; Vegetation index
In this study, a semi-arid shrubland in western New South Wales was used to test a number of vegetation indices developed from Landsat Thematic Mapper sensor data. Vegetation cover varied from a mean of 22% in mid-summer to a mean of 78% in mid
-winter. There was no significant relationship between the Normalised Difference Vegetation Index (NDVI) and summer vegetation cover, though there was a significant relationship with total vegetation cover in winter. The Landsat Thematic Mapper vegetation
indices most useful for monitoring vegetation in this semi-arid region are the Stress Related Index and the Australian Arid Rangelands Index.
Multiple stable states and models of riparian vegetation succession on the Animas River, Colorado
Berge ; Biogéographie ; Colorado ; Cours d'eau ; Crue ; Dynamique de la végétation ; Ecosystème ; Etats-Unis ; Modèle ; Végétation
Biogeography ; Colorado ; Ecosystem ; Flood ; Model ; Stream ; United States of America ; Vegetation ; Vegetation dynamics
This paper specifically examines the process of vegetation recovery following disturbance by exceptional natural floods along a river reach that is (and has been) comparatively undisturbed by human activities. It assesses a new successional model
, a state-and-transition model, which recognizes the possibility of multiple stable states in vegetation, via an investigation of the influence of fluvial processes and landforms on variation in a mosaic of riparian vegetation patches of different ages
Soil impact on satellite based vegetation monitoring in Sahelian Mali
AVHRR ; Analyse multivariée ; Dynamique de la végétation ; Formation herbacée ; Humidité du sol ; Indice de végétation ; Mali ; NOAA ; Propriétés du sol ; SPOT ; Sahel ; Sol ; Télédétection ; Végétation
This article examines to what extent the soil actually influences the Normalised Difference Vegetation Index (NDVI) based satellite monitoring of the Sahelian grasslands. A typical Sahelian landscape in the Gourma region in Mali is chosen as a case
This paper examines the literature on research into the effects of burial by deposition of blown sand, volcanic deposits (tephra, lavas and lahars) or fluvial sediment on vegetation and the subsequent capacity of the vegetation for survival
is then demonstrated by reference to macahir sand dune stratification in the Outer Hebrides and vegetation damage and burial following proximal volcanic impacts in New Zealand.
Die natürliche Vegetation der Bundesrepublik Deutschland. (La végétation naturelle en Allemagne de l'Ouest)
Allemagne de l'Ouest ; Association végétale ; Biogéographie ; Carte de la végétation ; Classification écologique des terres ; Europe centrale ; Géographie de l'Europe ; Végétation
Après avoir décrit à grands traits la flore et la végétation de l'Europe centrale, l'A. fait un rapide exposé de la végétation naturelle d'Allemagne de l'Ouest, des associations végétales caractéristiques et leurs relations avec les grandes unités
de végétation dont la répartition se fait principalement selon des critères écologiques.
Various aspects of both allogenic and autogenic processes in riparian vegetation dynamics are discussed here; in particular how plants may promote bank stability and sedimentation, and river island development. Riparian restoration often fails
Riparian vegetation variability along perennial streams in central Arizona
Analyse multivariée ; Arizona ; Cours d'eau ; Crue ; Distribution spatiale ; Dynamique de la végétation ; Ecosystème ; Etats-Unis ; Géométrie hydraulique ; Statistique ; Végétation ripicole
Arizona ; Channel geometry ; Ecosystem ; Flood ; Multivariate analysis ; Riparian vegetation ; Spatial distribution ; Statistics ; Stream ; United States of America ; Vegetation dynamics
This study clarifies linkages between fluvial hydrologic processes, fluvial landforms, and patterns of riparian vegetation populations by using a suite of geomorphic and hydrologic variables. 5 riparian vegetation populations were examined along 5
perennial streams in the transition zone of central Arizona. Canonical correspondance analysis (CCA) with a forward selection was used to assess quantitatively the role of stream power in riparian vegetation patterns.
Channel geometry ; Experimentation ; Meander ; Mississippi ; Riparian vegetation ; Stream ; Stream flow ; United States of America ; Vegetation
The aim of this study was to induce the location of the maximum surface velocity or thalweg of a straight, degraded stream channel to meander through the use of managed emergent vegetation. This study showed that flow velocity can be markedly
reduced within and near the vegetation zones, flow can be diverted toward the opposite bank, and vegetation density can control the magnitude of these effects. The following discussion will focus on design considerations for stream restoration
The emphasis of the research is to analyze the spatial-temporal character of vegetation change and the correlation with climate change, according to vegetation evolvement of West China from 1982 to 2000. Using NDVI data of NOAA-AVHRR
and the temperature and precipitation data of West China, the vegetation activity is discussed by adopting the EOF and REOF decomposed functions.
The phenological pattern of vegetation in Namaqualand, South Africa and its climatic correlates using NOAA-AVHRR NDVI data
AVHRR ; Afrique du Sud ; Indice de végétation ; NOAA ; Namaqualand ; Phénologie ; Télédétection ; Végétation
AVHRR ; NOAA ; Phenology ; Remote sensing ; South Africa ; Vegetation ; Vegetation index
Remote sensing techniques were used to reveal the vegetation patterns in the greater Namaqualand area and to relate them to climatic variables. The results suggest that NDVI (normalised difference vegetation index) can be used successfully to detect
growth and phenology patterns within different vegetation types in Namaqualand. - (AJC)
Biogéographie ; Phénologie ; Saisonnalité ; Végétation ; Zone intertropicale
Biogeography ; Phenology ; Seasonality ; Tropical zone ; Vegetation
Expression de la saisonnalité de la végétation tropicale. Revue des facteurs physiques responsables. Observation des floraisons, fructifications, croissance saisonnière du diamètre (anneaux de croissance), etc.. Méthodes de mesure. Diagramme
Définition des cartes écologiques de végétation et discussion sur la complexité de la végétation et de l'environnement. Cette complexité affecte l'utilité de ces cartes (difficulté d'interprétation). L'échelle a aussi d'importantes implications. (MI).