Économie écologique | EPFL Graph Search

thumb|400px|Les ressources naturelles traversent l'économie et finissent comme des déchets et de la pollution L’économie écologique est une branche de l'économie en interface avec l'écologie, étudiant l'interdépendance et la coévolution entre les sociétés humaines et les écosystèmes dans le temps et l'espace. L'intérêt de ces recherches est de pouvoir guider l'action des acteurs économiques (publics et privés) afin d'assurer un développement durable, c'est-à-dire conciliant progrès économique, justice sociale, et préservation de l'environnement, tout en mettant la priorité sur ce dernier point. Il faut distinguer l'économie écologique de l'économie environnementale qui vise à évaluer le coût économique des atteintes à l'environnement (en termes d'externalités) et la valeur monétaire des services écosystémiques dans le cadre de la théorie néoclassique. L'économie écologique a un caractère résolument holistique et transdisciplinaire, surmontant les barrières existantes entre les discip

Application of the denaturing gradient gel electrophoresis (DGGE) technique as an efficient diagnostic tool for ciliate communities in soil

Alexandre Jousset, Enrique Lara

Ciliates (or Ciliophora) are ubiquitous organisms which can be widely used as bioindicators in ecosystems exposed to anthropogenic and industrial influences. The evaluation of the environmental impact on soil ciliate communities with methods relying on morphology-based identification may be hampered by the large number of samples usually required for a statistically supported, reliable conclusion. Cultivation-independent molecular-biological diagnostic tools are a promising alternative to greatly simplify and accelerate such studies. In this present work a ciliate-specific fingerprint method based on the amplification of a phylogenetic marker gene (i.e. the 18S ribosomal RNA gene) with subsequent analysis by denaturing gradient gel electrophoresis (DGGE) was developed and used to monitor community shifts in a polycyclic aromatic hydrocarbon (PAH) polluted soil. The semi-nested approach generated ciliate-specific amplification products from all soil samples and allowed to distinguish community profiles from a PAH-polluted and a non-polluted control soil. Subsequent sequence analysis of excised bands provided evidence that polluted soil samples are dominated by organisms belonging to the class Colpodea. The general DGGE approach presented in this study might thus in principle serve as a fast and reproducible diagnostic tool, complementing and facilitating future ecological and ecotoxicological monitoring of ciliates in polluted habitats. (c) 2009 Elsevier B.V. All rights reserved.

2010

Spatio-temporal heterogeneity of riparian soil morphology in a restored floodplain

Géraldine Michèle Bullinger, Bertrand Fournier, Claire Guenat, Edward Mitchell

Floodplains have been intensively altered in industrialized countries, but are now increasingly being restored. It is therefore important to assess the effect of these restoration projects on the aquatic and terrestrial components of ecosystems. However, despite being functionally crucial components of terrestrial ecosystems, soils are generally overlooked in floodplain restoration assessments. We studied the spatio-temporal heterogeneity of soil morphology in a restored (riverbed widening) river reach along the River Thur (Switzerland) using three criteria (soil diversity, dynamism and typicality) and their associated indicators. We hypothesized that these criteria would correctly discriminate the post-restoration changes in soil morphology, and that these changes correspond to patterns of vascular plant diversity. Soil diversity and dynamism increased 5 yr after the restoration, but some typical soils of braided rivers were still missing. Soil typicality and dynamism were correlated to vegetation changes. These results suggest a limited success of the project, in agreement with evaluations carried out at the same site using other, more resource-demanding, methods (e.g., soil fauna, fish diversity, ecosystem functioning). Soil morphology provides structural and functional information on floodplain ecosystems. The spatio-temporal heterogeneity of soil morphology represents a cost-efficient ecological indicator that could easily be integrated into rapid assessment protocols of floodplain and river restoration projects. The follow-up assessment after several major floods (>= HQ20) should take place to allow for testing the longerterm validity of our conclusion for the River Thur site. More generally, it would be useful to apply the soil morphology indicator approach in different settings to test its broader applicability.

European Geosciences Union2013

Spatio-temporal heterogeneity of riparian soil morphology in a restored floodplain

Géraldine Michèle Bullinger, Bertrand Fournier, Claire Guenat, Edward Mitchell

European Geosciences Union2013