Pioneering investigations on the effects of introduced populations on community structure, ecosys... more Pioneering investigations on the effects of introduced populations on community structure, ecosystem functioning and services have focused on the effects of invaders on taxonomic diversity. However, taxonomic-based diversity metrics overlook the heterogeneity of species roles within and among communities. As the homogenizing effects of biological invasions on community and ecosystem processes can be subtle, they may require the use of functional diversity indices to be properly evidenced. Starting from the listing of the main used functional diversity indices, alongside with the presentation of their strengths and limitations, we further focus on studies pertaining to the effects of invasive species on native communities and recipient ecosystems obtained using functional diversity indices. By doing so, we reveal that functional diversity of the recipient community may strongly vary at the onset of the invasion process, while it stabilizes at intermediate and high levels of invasion. As functional changes occurring during the lag phase of an invasion have been poorly investigated, we show that it is still unknown if there are consistent changes in functional diversity metrics that could indicate the end of the lag phase. Thus, we highly recommend to provide information on the invasion stage under consideration when computing functional diversity metrics. For the existing literature, it is also surprising that very few studies explored the functional difference between organisms from the recipient communities and invaders of the same trophic levels, or assessed the effects of non-native organism establishment into a non-analogue versus an analogue community. By providing valuable tools for obtaining in-depth diagnostics of community structure and functioning, functional diversity indices valuable tools for on-time implementation of restoration plans and improved conservation strategies. To conclude, our work provides a first synthetic guide for their use in hypothesis testing in invasion biology.
HAL (Le Centre pour la Communication Scientifique Directe), 2011
Submerged macrophytes respond to environmental fluctuations in nutrient concentrations. A general... more Submerged macrophytes respond to environmental fluctuations in nutrient concentrations. A general framework for the assessment of aquatic macrophyte communities has been developed in France, in part using phytosociology tools and water chemical composition. A bioindication scale based on assessment of the macrophyte communities for the water trophic level was established in both hard and soft streams. The relationships between water chemistry and aquatic bryoflora in Eastern France were studied in an attempt to survey the processes of acidification. A bioindication scale based on the degree of acidification was proposed using aquatic plant communities.Subsequently, research in Europe focused on the development of synthetic indices that allowed for the quantification of water quality. Three main macrophyte indices are available for assessing the ecological status of water bodies as tested in accordance with the aims of the Water Framework Directive “WFD”. These are the Mean Trophic Rank (MTR), the Trophic Index of Macrophytes (TIM), and the French Biological Macrophyte Index for Rivers (IBMR). The MTR and IBMR indices could be useful for estimating the ecological status of rivers in accordance with the aims of the WFD. Ecological optima and ranges of submerged macrophytes are, amongst other factors, assumed to be influenced by ecoregion. Different macrophyte-based assessment systems have also been developed for application on lakes to fulfil the demands of the Water Framework Directive of the European Community. Aquatic macrophytes may be successfully used as ecological indicators for assessing and predicting environmental changes. The metal and nutrient bioaccumulation ability of macrophytes was also investigated. The use of aquatic macrophytes for treatment of wastewater to mitigate a variety of pollution levels is a research area of great interest. The removal efficiency of nutrients and of metals by macrophytes has been discussed in this non-exhaustive review. The potential use of these plants in wastewater treatment was also explored.
ABSTRACT In the Northern Vosges, the streams are characterized by a very low alkalinity and troph... more ABSTRACT In the Northern Vosges, the streams are characterized by a very low alkalinity and trophic level. 19 weakly mineralized streams were selected. A phytosociological study of these streams has been carried out according to the “Braun-Blanquet” method. The water samples were collected for analysis, each season, during the period 1993–1994. A Factorial Correspondance Analysis has allowed the classification of vegetation into four large plant communities. A Principal Components Analysis, processed on 37 sites and 12 physico-chemical variables, has showed a good agreement between macrophytic communities and physico-chemical parameters.The succession of water plant communities is related to water quality along a sequence A → B → C → D. An increase of water trophic level leads progressively from an oligotrophic vegetation to a meso- eutrophic community.
Pioneering investigations on the effects of introduced populations on community structure, ecosys... more Pioneering investigations on the effects of introduced populations on community structure, ecosystem functioning and services have focused on the effects of invaders on taxonomic diversity. However, taxonomic-based diversity metrics overlook the heterogeneity of species roles within and among communities. As the homogenizing effects of biological invasions on community and ecosystem processes can be subtle, they may require the use of functional diversity indices to be properly evidenced. Starting from the listing of the main used functional diversity indices, alongside with the presentation of their strengths and limitations, we further focus on studies pertaining to the effects of invasive species on native communities and recipient ecosystems obtained using functional diversity indices. By doing so, we reveal that functional diversity of the recipient community may strongly vary at the onset of the invasion process, while it stabilizes at intermediate and high levels of invasion. As functional changes occurring during the lag phase of an invasion have been poorly investigated, we show that it is still unknown if there are consistent changes in functional diversity metrics that could indicate the end of the lag phase. Thus, we highly recommend to provide information on the invasion stage under consideration when computing functional diversity metrics. For the existing literature, it is also surprising that very few studies explored the functional difference between organisms from the recipient communities and invaders of the same trophic levels, or assessed the effects of non-native organism establishment into a non-analogue versus an analogue community. By providing valuable tools for obtaining in-depth diagnostics of community structure and functioning, functional diversity indices valuable tools for on-time implementation of restoration plans and improved conservation strategies. To conclude, our work provides a first synthetic guide for their use in hypothesis testing in invasion biology.
HAL (Le Centre pour la Communication Scientifique Directe), 2011
Submerged macrophytes respond to environmental fluctuations in nutrient concentrations. A general... more Submerged macrophytes respond to environmental fluctuations in nutrient concentrations. A general framework for the assessment of aquatic macrophyte communities has been developed in France, in part using phytosociology tools and water chemical composition. A bioindication scale based on assessment of the macrophyte communities for the water trophic level was established in both hard and soft streams. The relationships between water chemistry and aquatic bryoflora in Eastern France were studied in an attempt to survey the processes of acidification. A bioindication scale based on the degree of acidification was proposed using aquatic plant communities.Subsequently, research in Europe focused on the development of synthetic indices that allowed for the quantification of water quality. Three main macrophyte indices are available for assessing the ecological status of water bodies as tested in accordance with the aims of the Water Framework Directive “WFD”. These are the Mean Trophic Rank (MTR), the Trophic Index of Macrophytes (TIM), and the French Biological Macrophyte Index for Rivers (IBMR). The MTR and IBMR indices could be useful for estimating the ecological status of rivers in accordance with the aims of the WFD. Ecological optima and ranges of submerged macrophytes are, amongst other factors, assumed to be influenced by ecoregion. Different macrophyte-based assessment systems have also been developed for application on lakes to fulfil the demands of the Water Framework Directive of the European Community. Aquatic macrophytes may be successfully used as ecological indicators for assessing and predicting environmental changes. The metal and nutrient bioaccumulation ability of macrophytes was also investigated. The use of aquatic macrophytes for treatment of wastewater to mitigate a variety of pollution levels is a research area of great interest. The removal efficiency of nutrients and of metals by macrophytes has been discussed in this non-exhaustive review. The potential use of these plants in wastewater treatment was also explored.
ABSTRACT In the Northern Vosges, the streams are characterized by a very low alkalinity and troph... more ABSTRACT In the Northern Vosges, the streams are characterized by a very low alkalinity and trophic level. 19 weakly mineralized streams were selected. A phytosociological study of these streams has been carried out according to the “Braun-Blanquet” method. The water samples were collected for analysis, each season, during the period 1993–1994. A Factorial Correspondance Analysis has allowed the classification of vegetation into four large plant communities. A Principal Components Analysis, processed on 37 sites and 12 physico-chemical variables, has showed a good agreement between macrophytic communities and physico-chemical parameters.The succession of water plant communities is related to water quality along a sequence A → B → C → D. An increase of water trophic level leads progressively from an oligotrophic vegetation to a meso- eutrophic community.
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Papers by Gabrielle Thiebaut