Studies on the potential vegetation of N. part of Sapporo, C. Hokkaido, Japan.
Action anthropique ; Biogéographie ; Dynamique de la végétation ; Dégradation de la végétation ; Ecosystème ; Gphy ; Géographie de l'Asie ; Hokkaido ; Ishikari ; Japon ; Phytogéographie ; Sapporo ; Végétation ; Végétation potentielle
L'A. distingue trois types de végétation: la végétation actuelle, originelle et potentielle. Analyse des modifications de la végétation en fonction de l'impact humain.
Late-Quaternary vegetational dynamics and community stability reconsidered
Amérique du Nord ; Dynamique de la végétation ; Géographie physique ; Paléobiogéographie ; Quaternaire ; Quaternaire supérieur ; Végétation
Defining the spatial and temporal limits of vegetational processes such as migration and invasion of established communities is a prerequisite to evaluating the degree of stability in plant communities through the late Quaternary. The interpretation
of changes in boundaries of major vegetation types over the past 20,000 yr offers a complementary view to that provided by migration maps for particular plant taxa. North of approximately 43N in eastern North America, continual vegetational disequilibrium has
resulted from climatic change, soil development, and species migrations during postglacial times. Between 33 and 39N, stable full-glacial vegetation was replaced by a relatively unstable vegetation during late-glacial climatic amelioration| stable
interglacial vegetation developed there after about 9000 yr B. P. Late-Quaternary vegetation has been in dynamic equilibrium, with a relatively constant flora, south of 33N on upland interfluves along the northern Gulf Coastal Plain, peninsular Florida
; Pollen ; Quaternaire zones moyennes ; Végétation ; Zone tempérée
L'A. étudie les directions de recherche, les développements récents en paléoclimatologie à partir des données polliniques (cartographie synoptique), et les travaux concernant les processus sous-jacents de la réponse de la végétation aux changements
climatiques. Il donne les controverses, les hypothèses et les nouvelles approches sur la détermination des transformations de la végétation au Quaternaire (Holocène).
Sukzession und Natürlichkeitsgrad synanthroper Vegetation zur Kennzeichnung und Bewertung ihrer Dynamik. (Succession and naturalness grade of synanthropic vegetation for its dynamical characterization and evaluation)
Action anthropique ; Ecosystème ; Géographie physique ; Paysage ; Stabilité ; Succession végétale ; Utilisation du sol ; Végétation
Des études sur le type et l'intensité d'utilisation du sol permettent d'évaluer l'impact de l'action anthropique sur la végétation naturelle et l'agression que celle-là constitue pour la stabilité de l'écosystème. Des observations de longue durée
Over fexible vegetation cover during windy conditions, a coupling of the airflow and the vegetation takes place, building up the waving form of the canopy surface and producing streamlining and fluttering phenomena. The investigation
The vegetational changes of the last 20,000 years at Telefomin, Papua New Guinea
Géographie de l'Océanie ; Montagne ; Palynologie ; Papouasie-Nouvelle Guinée ; Quaternaire supérieur ; Quaternaire zone chaude ; Sepik ; Telefomin, région ; Végétation ; Zone intertropicale
Végétation actuelle et reconstitution du paysage ancien végétal à l'aide d'analyses palynologiques à Telefomin (région de Sépik) en Papouasie-Nouvelle Guinée, à quelques kilomètres à l'Est de l'Irian Jaya en plein centre du massif montagneux. (OC).
It is only recently, however, that sufficient information has been gathered on past and present plant distributions to allow anything more than speculative reconstructions of the origins and development of the flora and vegetation. It is suggested
that sclerophyll vegetation developed largely from a Late Cretaceous/Early Tertiary immigrant flora in response to drier climatic conditions in the Late Tertiary and to a dramatic increase in burning with the arrival of aboriginal man in the Late Quaternary
Late Wisconsin macrofossil records of desert vegetation in the American Southwest
Recent discovery of macrofossil assemblages in the Mojave Desert extends the record of desert vegetation back to 14,800 yr ago and to altitudes as high as 910 m. Although xerophytic conifer woodland was widespread in current desert habitats during
the Late Wisconsin and early Holocene, the development of extensive desert vegetations was not delayed until the beginning of the middle Holocene. A regional vegetation mosaic of desert scrub and woodland existed at altitudes below 1000 m in the Mojave
Manuel bien structuré et dense sur le climat, l'hydrologie continentale (y compris des éléments de glaciologie) et la géographie de la végétation. La bibliographie est scindée en trois parties: celles réservées à la climatologie et à l'hydrologie
sont assez largement internationales alors que la partie se rapportant à la végétation est presque exclusivement germanophone.
Dry weight costs and establishment of seeds and vegetative propagules
Compositae ; Coût en matière sèche ; Dynamique des populations ; Expérimentation ; Géographie physique ; Reproduction ; Reproduction par bouturages ; Reproduction par graines ; Succès d'établissement ; Végétation
A garden experiment was conducted to investigate the relationship between the dry weight costs to a plant of producing seeds or vegetative propagules and their frequencies of establishment on a variety of substrates in five weedy Compositae
. Vegetative propagule weight was positively related and depth of burial negatively related to establishment success. The results are discussed in terms of costs per propagule, dispersal efficiency, and establishment success on different substrates.
Pollen records reveal a five-zone sequence of Holocene vegetation change since the initiation of sedimentation ca. 10,540 yr B.P. Initial vegetation on the newly deglaciated terrain reflects a relatively cool, moist macroclimate. Pollen Zone II (ca
Biomasse ; Ecologie quantitative ; Etalonnage ; Géographie physique ; Haute-Volta ; Pastoral ; Phytomasse herbacée ; Phénologie ; Radiométrie ; Steppe ; Structure de la végétation ; Technique de recherche ; Zone intertropicale
Up until now, the near infrared/red radiance ration (R) method has only been applied to artificial or semi-natural prairie vegetation composed of only one species. The main purpose of this paper is to evaluate the applicability of this remote
sensing technique on natural vegetation types of Sahelian shortgrassland in the North of Upper Volta (Oursi Pond, mean annual precipitation: 412 mm). The effects of vegetation structure and phenology on calibration relationships are examined
. The comparison of linear regression equations by means of analysis of covariance shows that, in practice, a separate calibration relationship is necessary for each vegetation type and for each phenological stage. At the end of the phenological cycle, when
vegetation turns brown due to the reduction of chlorophyll content, the reflectance ration decreases and the spectral measurement technique becomes unusable.
Carte internationale du tapis végétal et des conditions écologiques. Sumatra Sud = International map of the vegetation and of environmental conditions. Southern Sumatra.
Agriculture ; Bioclimat ; Carte ; Carte au 1:1 000 000 ; Généralités sur la géographie ; Indonésie ; Sol ; Sumatera ; Végétation ; Zone intertropicale ; Zoogéographie