Search results for "Ecosystem"

Biogeographic Atlas of the Southern Ocean.

2014

498 pages; International audience; The Southern Ocean waters to the west of the Antarctic Peninsula are warming faster than almost any other place on Earth. This area of most rapid environmental change was among others targeted by the Census of Antarctic Marine Life in its collection of biogeographic information. Such biogeographic information is of fundamental importance for monitoring biodiversity, discovering biodiversity hotspots, defining ecoregions and detecting the impacts of environmental changes. It is the preliminary and necessary step in designing marine protected areas in a changing ocean. At the end of five years of extensive biodiversity exploration and assessment by CAML (www…

Density-dependent effect affecting elephant seed-dispersed tree recruitment (Irvingia gabonensis) in Congo Forest.

2012

4 pages; International audience

Guide pratique de biostatistique

2022

A l’aide de clés de détermination simples et de cartes mentales, l’utilisateur de ce guide pratique pourra facilement identifier le test adéquat pour ses données en biologie et en écologie.Ce guide pratique de Biostatistique permet de choisir le test adapté au cas rencontré par l'étudiant ou l'enseignant en biologie. Il comporte plusieurs originalités majeures, notamment, la présentation des différentes étapes pour le choix et la conduite de tests statistiques pertinents, une adaptation du traitement des données sous R. Il inclut, à la fin de chaque chapitre, un arbre décisionnel des tests et des exercices choisis à partir de données biologiques et écologiques réelles tirées de la littératu…

Echinoids.

2014

Une chrysomèle contre l'ambroisie, est-ce réaliste ?

2016

Context - Despite intensive management practices carried out by stakeholders, common ragweed control is presently not sufficient to limit the spread of this annual invasive plant. Ali classical methods (mowing, chemical weeding, etc.) are limited in terms of efficiency. ln order to achieve a better management in the different habitats occupied by the plant, it is necessary to design innovative methods that could increase contra efficiency. The recent accidental introduction of a ragweed natural enemy in ltalia raises the question of the use of biological control agents. Could the regulation by a new phytophagous insect be considered as an integrated way of management in order to reduce the …

Permineralized coniferophytes from the Autun Basin: specimens from two new localities of Renault zone 3

2015

International audience; Four zones yielding silicified plant remains have been recognized in the Autun Basin by Renault (1893-1896). Zones 2, 3 and 4, characterized by Autunian plants, correspond to the successive formations of Igornay and Muse (lower Autunian), and Surmoulin-Millery (upper Autunian). Their paleobotanical content, together with that preserved as adpressions in the same formations, document paleofloral changes on the western side of the Tethys within a time interval extending from the latest Ghzelian (uppermost Pennsylvanian) to the early Sakmarian (lower Permian) (Broutin et al. 1999). The analyses realized so far indicate a progressive replacement of wetland plants by taxa…

La lutte biologique contre l'ambroisie à feuille d'armoise illustrée par l'exemple d'Ophraella communa : quels intérêts et quelles limites

2016

Common ragweed (Ambrosia artemisiifolia) was introduced in France over 150 years ago and its spreading across France now seems inexorable. The specific biology of this summer annual creates new problems for the managers of the various habitats where the plant can be found. The reduced possibility, or even the impossibility, to use traditional control means in certain environment conditions brings managers to consider biological control as one of the few possible means for slowing down the spread, or even pushing back the distribution area, of this invasive and allergenic plant. With Ophraella communa as an example, a reflection is presented on the benefit-risk balance of the introduction of…

Baselines and French Forests

2022

International audience

Decreasing Phanerozoic extinction intensity as a consequence of Earth surface oxygenation and metazoan ecophysiology

2021

The decline in background extinction rates of marine animals through geologic time is an established but unexplained feature of the Phanerozoic fossil record. There is also growing consensus that the ocean and atmosphere did not become oxygenated to near-modern levels until the mid-Paleozoic, coinciding with the onset of generally lower extinction rates. Physiological theory provides us with a possible causal link between these two observations-predicting that the synergistic impacts of oxygen and temperature on aerobic respiration would have made marine animals more vulnerable to ocean warming events during periods of limited surface oxygenation. Here, we evaluate the hypothesis that chang…

Determinants of the distribution of nitrogen-cycling microbial communities at the landscape-scale

2010

Little information is available regarding the landscape-scale distribution of microbial communities and its environmental determinants. However, a landscape perspective is needed to understand the relative importance of local and regional factors and land management for the microbial communities. In this manuscript, we investigated the distribution of functional microbial communities involved in N-cycling and of the total bacterial and crenarchaeal communities over 107 sites using a grid with a 16 km lag distance within Burgundy, a 31 500 km2 region in France. After quantifying the abundances of the total bacterial, crenarchaeal, nitrate-reducing, denitrifying and ammonia-oxidizing communit…