Sylvain Dolédec

• PhD
• Professor (Full) at Claude Bernard University Lyon 1

Motivation: Freshwater ecosystems have been heavily impacted by land-use changes, but data syntheses on these impacts are still limited. Here, we compiled a global database encompassing 241 studies with species abundance data (from multiple biological groups and geographic locations) across sites with different land-use categories. This compilation...

Motivation: Freshwater ecosystems have been heavily impacted by land-use changes, but data syntheses on these impacts are still limited. Here, we compiled a global database encompassing 241 studies with species abundance data (from multiplebiological groups and geographic locations) across sites with different land-use categories. This compilation...

Motivation: Freshwater ecosystems have been heavily impacted by land-use changes, but syntheses on the impacts on freshwater ecosystems are still limited. Here, we compiled a global database encompassing 248 studies with species abundance data (from multiple taxon groups and geographic locations) across sites with different land-use categories. Thi...

Motivation: Freshwater ecosystems have been heavily impacted by land-use changes, but syntheses on the impacts on freshwater ecosystems are still limited. Here, we compiled a global database encompassing 248 studies with species abundance data (from multiple taxon groups and geographic locations) across sites with different land-use categories. Thi...

Benthic cyanobacteria : proliferation factors and ecological risks in continental water bodies (in FRENCH) Benthic cyanobacteria are photosynthetic microorganisms that develop at the interface between sediment and water. The capacity of certain strains to produce toxins and the increasingly frequent deaths of mammals linked to their ingestion high...

Rivers of tropical islands formed by volcanic eruptions experience unpredictable and heavy rainfall and are characterised by irregular topography. During the 2019 and 2020 low-water season, we investigated the responses of benthic macroinvertebrate assemblages to variations in local environmental conditions in four rivers located in areas of differ...

In the sub-Antarctic region, climate change is particularly rapid, while their freshwater ecosystems, such as ponds, host plant species with limited spatial distributions. These particular systems and their plant communities remain however poorly known and the context of their changing habitat calls for deeper insights into these systems. We perfor...

The development of benthic cyanobacteria currently raises concern worldwide because of their potential to produce toxins. As a result, understanding which measures of biotic and abiotic parameters influence the development of cyanobacterial assemblages is of great importance to guide management actions. In this study, we investigate the relative co...

In this study, we address the diet of insect families collected from Haitian rivers "Reserve Biosphere de la Hotte" by quantifying ingested items and measuring their mouthparts.

From a literature review, we constructed a database comprising >1000 freshwater insect species (especially Odonata, Coleoptera, Trichoptera, Ephemeroptera; OCTE) in 26 Geographical Caribbean Units (GCU) and quantified local filtering (climate heterogeneity, annual rainfall, annual temperature), geography (area, distance from the mainland) and emerg...

We study the role of climate, geographical, geological and topographical factors in the species richness and composition of insects in the Caribbean archipelago.

• Global insect decline has recently become a cause for major concern, particularly in the tropics where the vast majority of species occurs. Deforestation is suggested as being a major driver of this decline, but how anthropogenic changes in landscape structure affect tropical insect communities has rarely been addressed. • We sampled Saturniidae...

Intermittent rivers and ephemeral streams (IRES) represent the majority of the global river network, support high biodiversity and provide multiple ecosystem services. However, they are being degraded at alarming rates, and it may be questioned whether current invertebrate-based biomonitoring protocols, which were designed for rivers and streams th...

Seasonal hydrological variation and chemical pollution represent two main drivers of freshwater biodiversity change in Mediterranean rivers. We investigated to what extent low flow conditions can modify the effects of chemical pollution on macroinvertebrate communities. To that purpose, we selected twelve sampling sites in the upper Tagus river bas...

Few studies have addressed how the diversity of basal resources change with stream regulation and the potential consequences on river biota. We sampled invertebrates above and below a series of dams, over two years, at both downwelling and upwelling zones. In each zone, we recorded the daily temperature and flow variations, estimated the algal deve...

The transferability of hydraulic microhabitat selection models among rivers has been largely debated. It can influence management decisions such as restoration measures or environmental flow definitions. We updated microhabitat selection models for 258 macroinvertebrate taxa, with 141 species, collected in 2128 Surber or Hess samples during 91 surv...

River‐groundwater exchanges are crucial for several ecological processes, but difficult to localize. Hyporheic oligochaetes may represent efficient biological indicators of these exchanges, but hydrological disturbance may alter oligochaete distribution and blur the spatial patterns of river‐groundwater exchanges. Oligochaete assemblages were compa...

Rivers suffer from more severe decreases in species diversity compared to other aquatic and terrestrial ecosystems due to a variety of pressures related to human activities. Species provide different roles in the functioning of the ecosystem, and their loss may reduce the capacity of the ecosystems to respond to multiple stressors. The effects on d...

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

The use of functional information in the form of species traits plays an important role in explaining biodiversity patterns and responses to environmental changes. Although relationships between species composition, their traits, and the environment have been extensively studied on a case-by-case basis, results are variable, and it remains unclear...

Initial colonists of empty habitats tend to differ from those arriving later in terms of species identity and traits. We evaluated the dynamics of the functional attributes in aquatic insect communities during a colonization experiment under natural conditions. We tested whether the late stages of colonization show higher functional richness, diver...

To assess evolutionary processes in deep time, it is essential to understand the roles of development and environment, both recorded through the morphological variability of fossil assemblages. Thanks to their great abundance and the high temporal resolution of their fossil record, conodont elements are ideal to address this issue. In this paper, w...

Urban wastewater effluents bring large amounts of nutrients, organic matter and organic microcontaminants into freshwater ecosystems. The effects of this complex mixture of pollutants on freshwater invertebrates have been studied mainly in temperate rivers and streams with high dilution capacities. In contrast, Mediterranean streams and rivers have...

Labile traits are those that are not constrained by phylogeny and should respond directly to the environment through local adaptation or phenotypic plasticity. For example, voltinism (number of generations per year) is a labile trait that has been consistently related to latitude and, in particular, to temperature and photoperiod changes. Current t...

Context: Understanding natural temporal changes in Mediterranean rivers with contrasting flow regimes in relation to those of temperate rivers may prove helpful in predicting effects of climate change on aquatic biodiversity. Goal: We aimed to compare temporal variability in taxonomic and trait compositions of nearly natural rivers in two climat...

Ecological criteria are needed for a comprehensive evaluation of groundwater ecosystem health by including biological components with the physical and chemical properties that are already required by European directives. Two methodological approaches to assess the ecological status of groundwater ecosystems were combined in two alluvial plains (the...

By modifying local habitat conditions, the alteration of land cover can result in severe faunal impairment, subsequently affecting ecosystem functioning. We analyzed changes in the composition of Ephemeroptera, Plecoptera and Trichoptera (EPT) assemblages along a gradient of human disturbance intensity in 66 neotropical savanna headwater stream sit...

The rates of species and trait diversification vary across the Tree-of-Life and over time. Whereas species richness and clade age generally are decoupled, the correlation of accumulated trait diversity of clades (trait disparity) with clade age remains poorly explored. Total trait disparity may be coupled with clade age if the growth of disparity (...

Stream invertebrate assemblages are structured by environmental factors acting at multiple spatial scales. Identifying the spatial scale that most influences the species–environment relationships is a major goal of community ecology. We evaluated the importance of catchment and site scales and associated environmental variables in shaping Ephemerop...

Stream invertebrate assemblages are structured by environmental factors acting at multiple spatial scales. Identifying the spatial scale that most influences the species–environment relationships is a major goal of community ecology. We evaluated the importance of catchment and site scales and associated environmental variables in shaping Ephemerop...

In freshwater ecosystems, Chironomidae are currently considered indicators of poor water quality because the family is often abundant in degraded sites. However, it incorporates taxa with a large ecological and physiological diversity and different sensitivity to impairment. Yet, the usual identification of Chironomidae at coarse taxonomic levels (...

Chironomidae (Diptera) are widespread, abundant, diverse and ubiquitous, and include genera and species that are distributed across the Holarctic region. However, the geographical barriers between continents should have resulted in intraspecific population differentiation with reflection on individual biological and ecological traits. Our aim was t...

The ecological niche concept has regained interest under environmental change (e.g., climate change, eutrophication, and habitat destruction), especially to study the impacts on niche shift and conservatism. Here, we propose the within outlying mean indexes (WitOMI), which refine the outlying mean index (OMI) analysis by using its properties in com...

WitOMI results and specie’s code. Tables S1 and S2 are the results of the OMI analysis, the value of the WitOMI parameters and their respective P values, for species of both ecological examples. Tables S3 and S4 are the respective code for each species of both ecological examples.

Within Outlying Mean Indexes Calculations. Mathematical description of the WitOMI parameters.

We used the trait composition of macroinvertebrate communities to identify the effects of pesticides and multiple stressors associated with urban land use at different sites of four rivers in Spain. Several physical and chemical stressors (high metal pollution, nutrients, elevated temperature and flow alterations) affected the urban sites. The occu...

Chironomidae are diverse and present a wide variety of ecological preferences. Thus, they have high potential in establishing reference conditions for river bioassessment and in providing functional information, especially when other macroinvertebrates are poorly represented. However, because of taxonomic difficulties and poor knowledge of traits,...

The ecological niche concept has a revival interest under climate change, especially to study its impact on niche shift and/or conservatism. Here, we propose the Within Outlying Mean Indexes (WitOMI), which refines the Outlying Mean Index (OMI) analysis by using its properties in combination with the K-select analysis species marginality decomposit...

The ecological niche concept has a revival interest under climate change, especially to study its impact on niche shift and/or conservatism. Here, we propose the Within Outlying Mean Indexes (WitOMI), which refines the Outlying Mean Index (OMI) analysis by using its properties in combination with the K-select analysis species marginality decomposit...

Although several studies have examined the functional diversity of freshwater macroinvertebrates, the variety of methodologies combined with the absence of a synthetic review make our understanding of this field incomplete. Therefore, we reviewed the current methodology for assessing functional diversity in freshwater macroinvertebrate research. Ou...

Agrarian reform has become at highly topical issue in Brazil and is proceeding mainly along the Amazonian pioneer fronts, thus jeopardising the continuity of forest cover. Although it is sometimes accompanied by highly proactive policies for sustainable development, the results of these policies are extremely variable. In this article, we compare f...

Context Multiple stressors constitute a serious threat to aquatic ecosystems, particularly in the Mediterranean region where water scarcity is likely to interact with other anthropogenic stressors. Biological traits potentially allow the unravelling of the effects of multiple stressors. However, thus far, trait-based approaches have failed to fully...

Local distribution of stream insects is influenced by abiotic factors, such as substrate heterogeneity and amount of organic matter. We evaluated the influence of substrate heterogeneity on the functional structure and diversity of stream macroinvertebrate communities based on 4 traits: feeding habits, body size, body shape, and attachment to subst...

Agrarian reform has become at highly topical issue in Brazil and is proceeding mainly along the Amazonian pioneer fronts, thus jeopardising the continuity of forest cover. Although it is sometimes accompanied by highly proactive policies for sustainable development, the results of these policies are extremely variable. In this article, we compare f...

We investigated the relationship between functional diversity and secondary production in an estuarine system subjected to anthropogenic impacts and climate events. Data consisted of a 14 yr long study of benthic invertebrate production from a seagrass bed and a sandflat. We used generalized linear models to test whether secondary production was ex...

1. A multiple-trait-based approach can provide predictions and interpretations of the responses of freshwater communities to river restoration that apply in different taxonomic contexts. We compared the observed and predicted effects of restoration on sets of traits in fish and invertebrate communi- ties in four reaches of the Rho^ne River. Restora...

Data‐rich restoration experiments offer opportunities to test the ability of bioassessment tools, such as those currently used to assess the ‘ecological status’ of waterbodies targeted by the European Water Framework Directive, to detect observed ecological changes. Minimum flow increases in four regulated reaches of the French Rhône River modified...

A multiple‐trait‐based approach can provide predictions and interpretations of the responses of freshwater communities to river restoration that apply in different taxonomic contexts. We compared the observed and predicted effects of restoration on sets of traits in fish and invertebrate communities in four reaches of the Rhône River. Restoration i...

Water scarcity is a serious environmental problem in many European regions, and will likely increase in the near future as a consequence of increased abstraction and climate change. Water scarcity exacerbates the effects of multiple stressors, and thus results in decreased water quality. It impacts river ecosystems, threatens the services they prov...

We considered an estuarine system having naturally low levels of diversity, but attaining considerable high production levels, and being subjected to different sorts of anthropogenic impacts and climate events to investigate the relationship between diversity and secondary production. Functional diversity measures were used to predict benthic produ...

Assessing trait responses to environmental gradients requires the simultaneous analysis of the information contained in three tables: L (species distribution across samples), R (environmental characteristics of samples), and Q (species traits). Among the available methods, the so-called fourth-corner and RLQ methods are two appealing alternatives t...

Lotic ecosystems worldwide are being increasingly modified hydromorphologically, for example, by damming, fragmentation, flow regulation and channel modification. Serious threats to riverine biodiversity are suspected, yet available field data are few and rarely address the various taxonomic, functional and phylogenetic components of biodiversity....

Landscape dynamics result from forestry and farming practices, both of which are expected to have diverse impacts on ecosystem services (ES). In this study, we investigated this general statement for regulating and supporting services via an assessment of ecosystem functions: climate regulation via carbon sequestration in soil and plant biomass, wa...

1. Despite a general recognition that benthic macroinvertebrates respond to changes in hydrological connectivity within floodplain ecosystems, no consensus about patterns in community structure and ecosystem processes across large scales and different climates has yet been established. Such knowledge is necessary since anthropogenic activities cont...

Quantifying the transferability across stream reaches and sampling occasions of models relating the density of aquatic taxa to microhabitat hydraulics are important for increasing our understanding of the mechanisms explaining microhabitat selection. We revisited data collected at multiple occasions in two regions, that is, in nine reaches of seven...

Rivers and floodplains are among the most threatened ecosystems. Hydroelectric power plants and embankments have reduced the hydrological connectivity between rivers and their floodplain channels, leading to loss of freshwater habitats and biological communities. To prevent and reverse such loss, numerous restoration programmes have aimed at rejuve...

1. Coleoptera species show considerable diversity in life histories and ecological strategies, which makes possible their wide distribution in freshwater habitats, including highly stressed ones such as saline or temporary waterbodies. Explaining how particular combinations of traits allow species to occupy distinctive habitats is a central questio...

A long-term programme of hydrological and ecological restoration has been conducted on the French Rhone River since 1998. Its main components are i) the increase of the minimum flow in the river sections bypassed by an hydro-power plant, ii) the direct reconnection of cut-off channels to the river, iii) the dredging of isolated pools within the cha...

Biological traits are increasingly used for describing ecological functioning of stream benthic assemblages. Such approaches associate information on species distribution to their biological characteristics (e.g. life history, physiology, dispersal ability) providing a biological trait profile of communities. They may complement structural bioasses...

Groundwaters are increasingly viewed as resource-limited ecosystems in which fluxes of dissolved organic carbon (DOC) from surface water are efficiently mineralized by a consortium of microorganisms which are grazed by invertebrates. We tested for the effect of groundwater recharge on resource supply and trophic interactions by measuring physico-ch...

The retreat-making larvae of many lotic caddisflies build entirely new pupal cases with fine gravel and sand that they collect in the neighbourhood of the building place to fix it with silk to cobbles in swift flow (where finer sediments are generally rare). Previous field observations on Hydropsyche siltalai pupal cases illustrate that natural loc...

Aim To investigate spatial autocorrelation of taxonomic stream invertebrate groups (richness and composition) at a large geographical scale and to analyse the importance of exogenous and endogenous factors. Location The Mediterranean Basin. Methods For exogenous factors, we used large-scale factors related to climate, geology and river zonation; fo...

Do mediterranean genera not included in Tachet et al. 2002 have mediterranean trait characteristics? Multiple-trait databases are increasingly used in community ecology in different regions of the world. In Europe, Tachet et al. (2002) compiled an aquatic macroinvertebrate database for 473 taxa using information on 11 biological traits described by...

When Illies published his concept on the longitudinal zonation of lotic invertebrates five decades ago (Illies, J., 1961: Internat. Rev. ges. Hydrobiol. 46: 205–213), he defined a research topic that currently interests many ecologists because he linked speciation and phylogeny with spatial distribution and trait adaptation to environmental conditi...

1. Large-scale comparative studies of ecological responses to anthropological stressors in rivers require measures that are consistent across a range of spatial scales. The biological trait profile of communities offers an alternative approach to traditional measures of macroinvertebrate taxonomic identity and is less constrained by biogeographic i...

Recent work on the development of suitable indicators to report on landscapes and their various components has often been limited to studies of landscape composition and/or structure. However, to grasp the complexity of landscape mosaics, it is important to have synoptic indicators, whose development is all the more relevant as many studies place l...

Recent work on the development of suitable indicators to report on landscapes and their various components has often been limited to studies of landscape composition and/or structure. However, to grasp the complexity of landscape mosaics, it is important to have synoptic indicators, whose development is all the more relevant as many studies place l...

Rigorous and widely applicable indicators of biodiversity are needed to monitor the responses of ecosystems to global change and design effective conservation schemes. Among the potential indicators of biodiversity, those based on the functional traits of species and communities are interesting because they can be generalized to similar habitats an...

We comment on a criticism of hydraulic preference models and instream habitat models. We provide evidence of the generality of many hydraulic preference models, which supports their use in instream habitat modelling even if the detailed mechanistic causes of the observed preferences are not fully known. We also reply to the assertion that preferenc...

In two Amazonian regions of Brazil and Colombia that represent most of the diversity of the pioneer front landscapes, we searched for relationships among socioeconomic environments, landscape composition and structure, biodiversity, and production of goods and ecosystem services. An original sampling protocol was applied to collect fully compatible...

Taxonomy is undoubtedly complementary to other fields in biology such as ecology, and both ecologists and taxonomists increasingly acknowledge that they can profit from phylogenetic ecology or ecological phylogeny, respectively. However, such mutual relations between these disciplines are constrained by traditional focuses on different operational...

Since late 90s, the valuation of ecosystem services (ES) has become a fundamental principle for fulfilling poverty alleviation and biodiversity conservation. As a result, scientific studies as well as management projects applying ES have proliferated, scarcely proposing a proper integration of ecological and social issues. Here, we question the uni...

Effective ecosystem management in the face of human alterations depends on our ability to quantify ecologically significant changes and to discriminate among impact levels and types. We reviewed the literature on biological responses of freshwater biota to human disturbances over the last century. Many of the main methods for assessing ecological i...

We characterized the first microsatellite markers for Gammarus fossarum. Eight loci gave satisfactory amplification patterns in two stream populations (Southern France) with number of alleles ranging from 2 to 10 and expected heterozygosity from 0.076 to 0.857. We performed cross-amplification in two closely related gammarid species, Gammarus pulex...

Water Framework Directive (WFD) fostered research interest on bioassessment tools to evaluate the ecological integrity of surface waters. The application of WFD implies the reliability enhancement of existing bioassessment tools to larger geographic areas for a better convergence across European Union (UE) state members as well as the maintenance o...

Instream habitat models are attractive tools for assessing the impacts of flow restoration on aquatic organisms, but have been rarely used for invertebrates due to the lack of knowledge of their hydraulic preferences. In this study, we provide quantitative models of the hydraulic preferences for 66 invertebrate taxa found in the Upper Rhône River (...

This article was submitted without an abstract, please refer to the full-text PDF file.

This article was submitted without an abstract, please refer to the full-text PDF file.

Recent syntheses demonstrate that functional composition more often controls ecosystem functioning than does species diversity. Functional trait approaches thus provide a framework to identify biotic mechanisms relevant to ecosystem service delivery. Many ecosystem functions rely on interactions between primary producers and other trophic levels (c...

Floodplains are species‐rich environments often strongly impacted by human activities. In particular, the negative effects of progressive and rapid disconnection of secondary channels have led to restoration programmes and a growing interest in restoration ecology. Current restoration strategies in large river floodplains focus on the macroinverteb...

In developed countries, changes in agriculture practices have greatly accelerated the degradation of the landscape and the functioning of adjacent aquatic ecosystems. Such alteration can in turn impair the services provided by aquatic ecosystems, namely the decomposition of organic matter, a key process in most small streams. To study this alterati...

1. Ecological theory predicts that (1) proportions of fish having particular life history strategies should vary with habitat conditions, and (2) biological traits of species should change across spatio-temporal variability gradients (River Habitat Templet). 2. We used data on juvenile fish and biological traits of the species, temporal (i.e. hydro...

The Ponto-Caspian gammarid Dikerogammarus villosus currently expands its range and replaces native gammarid populations in many large rivers of Europe. Results of small-scale, still-water experimentation fostered the idea that D. villosus reduces native gammarid populations in large rivers through predation. However, in large rivers, the prevailing...