Après un bref rappel de quelques notions de base (types de végétation, bilan carboné des éco-systèmes, photosynthèse, respiration des plantes et des décomposeurs), l'A. s'interroge sur la réponse possible des arbres et des forêts à l'augmentation du
CO2 atmosphérique, puis pose la question de savoir si la végétation peut s'opposer au réchauffement global en fixant davantage de carbone. - (JPB)
Biogeography ; Biomass ; Carbon ; Ecosystem ; European part of Russia ; Mountain ; Murmansk ; Soil ; Spatial analysis ; Tundra ; Vegetation
Données sur la distribution des communautés de plantes, leur productivité et les principales réserves de carbone dans la végétation et les sols de toundra de montagne. Variation des caractéristiques de cet écosystème avec le gradient topographie
Carbon fluxes from eroding peatlands – the carbon benefit of revegetation following wildfire
Bassin-versant ; Cycle du carbone ; Derbyshire ; Ecologie appliquée ; England ; Peak District National Park ; Restauration écologique ; Royaume-Uni ; Séquestration du carbone ; Tourbière
Applied ecology ; Carbon cycle ; Carbon sequestration ; Derbyshire ; Ecological restoration ; England ; Peat bog ; United Kingdom ; Watershed
The AA. measured the carbon budget of 8 sites: 4 restored-revegetated sites, 2 unrestored bare soil control sites, and 2 intact vegetated controls over 2 years (2006-2008). They considered the following flux pathways: dissolved organic carbon (DOC
than observed for vegetated controls. Therefore, the carbon sequestration benefit of peatland restoration is evaluated.
); particulate organic carbon (POC); dissolved carbon dioxide (CO2); primary productivity; net ecosystem respiration, and methane (CH4). The study shows that unrestored, bare peat sites can have significant carbon losses. Most sites showed improved carbon budgets
(decreased source and/or increased sink of carbon) after restoration; this improvement was mainly in the form of a reduction in the size of the net carbon source, but for one restored site the measured carbon budget after 4 years of restoration was greater
C 14 dating ; Carbon ; Climatic variation ; Grassland ; Holocene ; Isotope analysis ; Palaeobiogeography ; Quaternary ; South Dakota ; United States of America ; Vegetation
Analyses of phytoliths and carbon isotopes document the rate and nature change in late Quaternary grasslands in the Red Valley of the southern Black Hills. This paper will evaluate the temporal sensitivity and spatial limits of the methods.
It appears that in the sparsely vegetated Mojave Desert, the C13/C12 of pedogenic carbonate is controlled by differences in plant density and biological activity. This relationship may provide a tool for assessing past vegetational densities
, as long as the vegetation is isotopically homogeneous.
The effect of vegetation in reducing carbon monoxide
Atmosphère ; Climat urbain ; Climatologie appliquée ; Concentration ; Effet ; Géographie de l'Asie ; Honshu ; Japon ; Monoxyde de carbone ; Pollution ; Pollution atmosphérique ; Sendai ; Ville ; Végétation
En milieu urbain, à Sendai, on observe de fortes concentrations de monoxyde de carbone aux carrefours des artères. Les obstacles tels que bâtiments et palissades, affectent également les taux de concentrations. La ventilation a un effet certain pour
atténuer le monoxyde de carbone| corrélativement on a observé des taux plus bas dans les zones plantées. On ne peut cependant déterminer la part des arbres/pelouses.
Impact of deposition on the enrichment of organic carbon in eroded sediment
Bassin-versant ; Enrichissement ; Erosion des sols ; Expérimentation de terrain ; Matière organique ; Sédimentaire ; Topographie ; Transport sédimentaire ; Végétation
Field experiment ; Organic materials ; Sediment transport ; Sedimentary ; Soil erosion ; Topography ; Vegetation ; Watershed
Examen de l'enrichissement en carbone organique dans les sédiments transportés en relation avec les dépôts induits par la topographie et la végétation.
Stable carbon isotope analyses were performed on organic carbon from the late Quaternary alluvial deposits and soils along three streams within the Fort Hood Military Reservation of central Texas. This paper presents the results
of this investigation and proposes a late Quaternary vegetation and climate history for central Texas. These reconstructions are then compared with other paleoclimatic records from central and north Texas and the Great Plains.
Analyse bibliographique des développements des recherches à la fois réductionniste et holistique qui ont accru la connaissance de la façon dont les émissions atmosphériques affectent la végétation.
Changes in labile soil organic carbon fractions in wetland ecosystems along a latitudinal gradient in Northeast China
Biogéochimie ; Carbone ; Chine ; Chine du Nord-Est ; Dégradation de l'environnement ; Ecosystème ; Latitude ; Milieu humide ; Pergélisol ; Périglaciaire ; Réchauffement climatique ; Végétation
Biogeochemistry ; Carbon ; China ; Climatic warming ; Ecosystem ; Environmental degradation ; Humid environment ; Latitude ; North-Eastern China ; Periglacial features ; Permafrost ; Vegetation
latitude, vegetation affected SOC stock and the dynamics of its labile fractions. Therefore, wetlands in mid-high latitudes contain a large carbon pool, and carbon stock varies with latitude. Although the labile fractions were higher in the permafrost
region, their activities were lower, due to low temperature and poor nutrient status. Under global warming, the labile carbon pool may be mobilized and contribute to the greenhouse effect. Moreover, vegetation differences should be considered in obtaining
Topsoil (0–20 cm) was collected from 5 wetlands along a latitudinal gradient in Northeast China. The AA. analyzed soil organic carbon (SOC) and some labile fractions. Their results demonstrated that wetland SOC and its labile fractions concentration
declined with decreasing latitude. The Permafrost regions had greater organic carbon content than the regions with seasonally frozen ground. Microbial biomass carbon and dissolved organic carbon showed a similar decreasing trend to that of SOC. At the same
The AA. analyzed and estimated the distribution and reserves of soil organic carbon under nine different vegetation conditions including alpine meadow, meadow steppe, typical steppe, desert steppe, and temperate coniferous forest and so
on, in the Ili River valley, Xinjiang, according to data from field investigations and laboratory analyses in 2008 and 2009. The study results show that the soil organic carbon content in the Ili River valley varies with the type of vegetation. The AA. pay
special attention to the characteristics of soil organic carbon in the meadow ecosystem in the Ili River valley, so as to lay a foundation for further studies on a regional-scale soil carbon cycle.
The comparative role of key environmental factors in determining savanna productivity and carbon fluxes : a review with spatial reference to northern Australia
Australia ; Carbon cycle ; Carbon dioxide ; Climatic change ; Ecosystem ; Fire ; Northern Territory ; Precipitation ; Productivity ; Radiation ; Savanna ; Temperature
For savannas, the key environmental drivers controlling vegetation productivity are water and nutrient availability, vapour pressure deficit (VPD), solar radiation and fire. Changes in these environmental factors can modify the carbon balance
of these ecosystems. Here the AA. have reviewed the various environmental controls on the spatial and temporal patterns on savanna carbon fluxes in northern Australia. Such studies are critical in predicting the impacts of future climate change on savanna productivity
Late Quaternary vegetation dynamics in the southern Amazon Basin inferred from carbon isotopes in soil organic matter
Amazonie ; Amérique du Sud ; Analyse isotopique ; Carbone ; Datation C 14 ; Dynamique de la végétation ; Forêt ; Holocène ; Paléo-environnement ; Quaternaire ; Savane ; Variation climatique
Amazon Basin ; C 14 dating ; Carbon ; Climatic variation ; Forest ; Holocene ; Isotope analysis ; Palaeo-environment ; Quaternary ; Savanna ; South America ; Vegetation dynamics
Carbon isotopes of soil organic matter (SOM) were used to evaluate and establish the chronology of the vegetation dynamics of an ecosystem presently composed of savannas surrounded by forests. The study was carried out on a 200-km transect along
highway BR 319, on the border of Amazonas and Rondônia states, in southern Amazon, Brazil. The results indicate that extensive forested areas existed in the Amazon during the last glaciation and that savanna vegetation expanded in response to warm and dry
The purpose of this work is to explore the possibility of using the stable isotopic composition of carbon in phytoliths to reconstruct aspects of paleoenvironmental conditions. The basis for this approach is related to the influence of climate
Satellite-derived vegetation index and cover type maps for estimating carbon dioxide flux for arctic tundra regions
Alaska ; Bassin-versant ; Dioxyde de carbone ; Indice de végétation ; LANDSAT ; MSS ; Région polaire ; SPOT ; Toundra ; Traitement des données ; Télédétection ; Végétation
Alaska ; Carbon dioxide ; Data processing ; LANDSAT ; MSS ; Polar region ; Remote sensing ; SPOT ; Tundra ; Vegetation ; Vegetation index ; Watershed
The AA. compared satellite NDVI maps for the Kuparuk River watershed generated at 2 different spatial resolutions to a general map of vegetation types derived by image classification of Landsat multispectral scanner (MSS) data. Descriptive
, inferential, and spatial statistics were generated to assess spatial variability and co-variability of NDVI and vegetation types at landscape scales throughout the Kuparuk River watershed of the North Slope of Alaska.
Vegetation dynamics during the late Pleistocene in the Barreirinhas region, Maranhão State, northeastern Brazil, based on carbon isotopes in soil organic matter
Analyse isotopique ; Brésil ; Carbone ; Charbon de bois ; Dynamique de la végétation ; Maranhâo ; Matière organique ; Paléobiogéographie ; Pléistocène ; Propriétés du sol ; Quaternaire ; Sol
A vegetation transect of 78 km was studied among 4 vegetation types : Restinga (coastal vegetation), Cerrado (woody savanna), Cerradão (dense woody savanna), and Forest, as well as three forested sites around Lagoa do Caçó, located approximately 10
km of the transect. Soil profiles in this transect were sampled for δ13 C analysis, as well as buried charcoal fragments were used for 14 C dating. The vegetation dynamic inferred in this study for northeastern Brazil is in agreement with the results
Actual and potential carbon stocks in the north-sudanian zone. A case study : the forests of Delbi and Paniates in Senegal
Carbone ; Dégradation de la végétation ; Développement durable ; Effet de serre ; Forêt ; Gestion de l'environnement ; Protection de la nature ; Savane ; Sénégal
Cet article étudie les potentialités de stockage du carbone dans 2 forêts plus ou moins dégradées au Sénégal : les forêts de Delbi et Paniates, en zone nord-soudanienne. Les résultats montrent que les 2 sites possèdent des quantités de carbone
les causes réelles de ce faible niveau d'émission de carbone.
Combining LPJ-GUESS and HASM to simulate the spatial distribution of forest vegetationcarbon stock in China
Chine ; Cycle du carbone ; Distribution spatiale ; Ecosystème ; Forêt ; Gestion de l'environnement ; Modèle ; Simulation ; Séquestration du carbone
Carbon cycle ; Carbon sequestration ; China ; Ecosystem ; Environmental management ; Forest ; Model ; Simulation ; Spatial distribution
This paper, based on High Accuracy Surface Modeling (HASM), proposes a forest vegetationcarbon storage simulation method. This new method employs the output of LPJ-GUESS model as initial values of HASM and uses the inventory data as sample points
of HASM to simulate the distribution of forest carbon storage in China. This study also adopts the seventh forest resources statistics of China as the data source to generate sample points, and it also works as the simulation accuracy test. The simulation
result indicates that the southwestern mountain region and the northeastern forests are the important forest carbon reservoirs in China. Compared with the former value (1975-1995), it manifests that the carbon storage of the 2 regions do increase clearly
. The results of this research show that the large-scale reforestation in the last decades in China attains a significant carbon sink.
Carbon dioxide fluxes and DOC concentrations of eroding blanket peat gullies
Carbone ; Cycle du carbone ; Derbyshire ; Dioxyde de carbone ; Ecosystème ; England ; Erosion hydrique ; Géochimie ; Photosynthèse ; Ravinement ; Royaume-Uni ; Tourbière ; Végétation
Carbon ; Carbon cycle ; Carbon dioxide ; Derbyshire ; Ecosystem ; England ; Geochemistry ; Gully erosion ; Peat bog ; Photosynthesis ; United Kingdom ; Vegetation ; Water erosion
and ecosystem respiration, though net ecosystem exchange is not significantly different across the gully. While gully position plays a role in the cycling of some carbon species, this study highlights the importance of vegetation as a key control on carbon
This study uses a series of gully sites across the Bleaklow plateau (Peak District, Derbyshire), subject to different restoration interventions, to investigate differences in carbon pathways (DOC, CO2) and hydrology between restoration strategies