Relevance and reproductibility of rapid indicators for the evaluation of wetlands' functions : comparison with indicators based on more detailed data from RhoMéO's programme

Abstract

French regulations increasingly require that offset compensate not only wetland surfaces but also wetland functions when impact related to development occurs on these ecosystems. In recognition for the need of a reliable method that could be used to assess wetland functions in a reasonable time and with simple equipment, a prototype of rapid assessment method (half a day in office, half a day in the field) was developed (Gayet et al., 2016). Based on an important bibliographic work, this method (called MEFZH in this article) allows to calculate a large set of indicators related to hydrological, biogeochemical and environmental functions. In order to validate this method for the country of Isère, we checked it's reproducibility and compared the results obtained on a given site with more detailed data from the wetlands' monitoring program RhoMéO. The reproductibility of MEFZH was good for 38 out of 41 indicators. Also, we showed that there was a significant relationship between several MEFZH indicators and the RhoMéO data. It was not the case, however, for two indicators related to environmental function. These results were taken into account in the final version of the method. As a conclusion, we discuss the limits of our approach. Because RhoMéO program provided few data related to biogeochemical processes, we recommend to constitute a network of wetlands for which exhaustive data exist, especially concerning those processes, in order to validate with field data the indicators of MEFZH that were based exclusively on bibliographical work.