Séminaire de Clive Jones, à l’AgroParisTech, organisé par Gaié


Clive G. Jones donnera un séminaire sur l’allométrie et l’ingénierie des écosystèmes le mardi 29 octobre à 14h, à AgroParisTech (16 rue Claude Bernard, Paris), amphi Coléou.

Présentation de Clive G. Jones :

Les recherches du Dr. Clive G. Jones portent sur l’ingénierie des écosystèmes par les organismes, ainsi que sur l’utilisation des processus écologiques pour une gestion durable de l’environnement : l’ingénierie écologique. Il a un goût prononcé pour la synthèse, l’intégration et la théorie en écologie. Il a publié plus de 190 articles dont l’article fondateur sur le concept d’organisme ingénieur (Jones et al., 1994), cité plus de 2700 fois. Il est un des membres fondateurs du groupe Gaié. Il est aussi membre élu de l’ American Association for the Advancement of Science.

Il travaille en tant que Senior Scientist au Cary Institute of Ecosystem Studies (NY, USA). Il est membre de l’Association pour l’Avancement de la Science et s’est vu décerner une Chaire Internationale de Recherche Blaise Pascal. Il a été récemment professeur invité à AgroParisTech et Visiting Professor à la Royal Netherlands Academy for Arts and Sciences. Pour plus d’informations : http://www.caryinstitute.org/scienc...

**************** Seminar Title : "Allometry & Ecosystem Engineering : Body Size, Growth Rate & Extrinsic Environmental Modification by Species".

Abstract : Ecosystem engineering — the physical modification of the environment by species — is now well-recognized as a very common, often influential kind of ecological interaction. Although we understand many of the factors influencing the magnitude of the effects of ecosystem engineers on the physical environment, other species and ecological processes, as well as feedbacks to engineers, the major challenge of being able to quantitatively predict and compare effects across diverse engineering species in diverse environments has remained elusive. Here I show that we can make considerable progress in meeting this challenge by applying allometric theory - traditionally, the relationships between body size or growth rate and intrinsic characteristics of species - to ecosystem engineering ; in other words, the relationships between body size and growth rate and the extended influence of species into their surrounding physical environments. More specifically, using empirical data sets compiled from the literature across a wide range of body sizes, growth rates, environment types, and environmental effect magnitudes for burrow volume, soil and sediment turnover rates, and erosion rates of corals and other substrates, I show that : (i) body size or growth rate account for much of the variation in effect magnitudes of ecosystem engineers on their proximal physical environments ; and that (ii) species geometry - their three dimensions ’embedded’ in their body sizes and growth rates (i.e., their ’intrinsically available tools for environmental modification’) emerge as a fundamental primary determinant of environmental effect magnitudes, although metabolic requirements and a few other factors sometimes account for additional variation. These relationships : Allow us to quantitatively predict and compare the effects of engineering species ; ascertain whether or not a species has an effect that is disproportionately greater or less than expected from its biomass, i.e., whether or not it is a ’keystone’ engineer ; can be used to scale up effects in space, such as the geographic range of an engineer ; can be used to integrate multiple engineering species in a given locale ; and can be of value in conservation, restoration and environmental management. Finally, these relationships permit coupling of engineer characteristics with the known responses of species and other ecological processes to environmental change, moving us toward a general, quantitative, predictive and comparative theory of ecosystem engineering.

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