Florian Malard

Claude Bernard University Lyon 1 | UCBL · UMR CNRS 5023

Negotiations are underway on the new European Union (EU) Water Directive (1), which will regulate the protection and sustainable use of Europe’s water resources. However, the proposal foregoes environmental quality standards specifically tailored to sensitive groundwater species and fails to require biomonitoring for groundwater ecosystems. Despite...

We report on a new species of Stenasellus Dollfus, 1897 (Isopoda, Stenasellidae) from groundwater of Iran. Stenasellus stygopersicus Jugovic, Malek-Hosseini & Issartel sp. nov. inhabits the Chah Kabootari Cave that is adjacent to the Tashan Cave, the type locality of the first recorded species of Stenasellidae from Iran, Stenasellus tashanicus Khal...

The subfamily Candoninae, one of the most species-rich lineages of non-marine Ostracoda, includes now about 550 extant species across more than 50 genera classified in seven tribes (MEISCH et al., 2019). The tribe Candonopsini is usually distinguished on the basis of the absence of posterior seta on the caudal ramus, but due to the frequent reducti...

Isopods are a diverse group of crustaceans, that inhabit various environments, including terrestrial, freshwater, and marine, both on the surface and in the underground. The biological mechanisms underlying their wide range of adaptations to diverse ecological niches remain elusive. In order to unravel the molecular basis of their adaptability, we...

Since the first edition of “Groundwater Ecology” was published almost 3 decades ago, the knowledge of ecology and evolution of biodiversity in groundwater has grown tremendously. This overdue second edition does not replace the first one but is complementary to it. The first edition largely focused on case studies of groundwater ecosystems, while t...

Subterranean ecosystems (comprising terrestrial, semi-aquatic, and aquatic components) are increasingly threatened by human activities; however, the current network of surface-protected areas is inadequate to safeguard subterranean biodiversity. Establishing protected areas for subterranean ecosystems is challenging. First, there are technical obst...

Groundwater is a vital ecosystem of the global water cycle, hosting unique biodiversity and providing essential services to societies. Despite being the largest unfrozen freshwater resource, in a period of depletion by extraction and pollution, groundwater environments have been repeatedly overlooked in global biodiversity conservation agendas. Dis...

Niphargus is the most speciose amphipod genus inhabiting groundwater of the Western Palearctic, counting over 450 described species. The genus is known for its problematic taxonomy, including large within-, yet sometimes negligible between-species variation, often associated with cryptic diversity. With the onset of the molecular methods, it became...

The Dinarides in the Western Balkans host a globally exceptional subterranean biodiversity, but still areas remain with little or no data on subterranean species. In this work, we present the study of subterranean fauna in the upper Neretva River catchment (Eastern Bosnia and Herzegovina), which included the first systematic exploration of the inte...

The Commonwealth of Virginia has the most diverse array of aquatic isopods living in groundwater-related habitats of any state in the United States. In Virginia, 44 species occur in karst habitats (caves and springs) of the Appalachian Valley and Ridge Province, and in shallow groundwater habitats of the Atlantic Coastal Plain Province. The majorit...

Transition to novel environments, such as groundwater colonization by surface organisms, provides an excellent research ground to study phenotypic evolution. However, interspecific comparative studies on evolution to groundwater life are few because of the challenge in assembling large ecological and molecular resources for species‐rich taxa compri...

Aim: Morphologically cryptic species are an important part of global biodiversity, yet it remains unclear how these species contribute to and integrate into communities at different geographic scales. It is especially unclear at which scales they co-occur, and if and how their ranges overlap. To adequately protect biodiversity, an accurate understa...

Dispersal, the movement of individuals across space, has important consequences at individual, population, species, community, and ecosystem levels. Dispersal depends on phenotypic traits influencing the propensity of an organism to disperse and extrinsic environmental features. Factors selecting for dispersal include environmental unpredictability...

We review generalizations that emerge from the contributions in the second edition of “Groundwater Ecology and Evolution,” finding they fall within an overarching theme to which we refer as “the ecological and evolutionary unity and diversity of groundwater ecosystems.” Continuing exploration of the groundwater biosphere is changing our perception...

Understanding patterns of groundwater biodiversity is a challenging task because of the inherent difficulty in drawing links between environmental factors, eco-evolutionary processes, and patterns. Using studies in Europe, the Americas, and Australia, we focus on patterns that are common enough among taxonomic groups and continents in species richn...

Groundwater ecosystems are very diverse in respect to biodiversity and physical environment. These open systems are strongly connected to the open water as well as adjacent terrestrial and atmospheric ecosystems. Groundwater taxa represent a large array of biota including viruses, prokaryotes (bacteria and archaea), microeukaryotes (fungi and proti...

Groundwater is a vital ecosystem of the global water cycle, hosting unique biodiversity and providing essential services to societies. Despite being the largest unfrozen freshwater resource, in a period of depletion by extraction and pollution, groundwater environments have been repeatedly overlooked in global biodiversity conservation agendas. Dis...

ABSTRACT: Since the first discoveries in the 1860s of subterranean organisms in France, there has been a sustained effort in sampling and identifying subterranean species. Yet, the species inventory is still largely incomplete. Since the nineties, breakthrough in molecular methods has revolutionized concepts and practices guiding species inventory....

With only 43 described stygobionts and only two isopod species the obligate groundwater fauna of Iran, a vast country with over 10% of limestone surface, is inadequately known. Here, we report the discovery of Asellus ismailsezarii sp. nov. from Zagros mountains, the first eyeless and depigmented asellid isopod from Iran. The new species is morphol...

Understanding and predicting the geographic distribution of taxa in hierarchical stream landscapes is a cornerstone of river ecology. A central issue is to tease apart the unique and shared effects of local and catchment predictors over species distributions. Here, we tested Hynes's influential hypothesis (1975, Baldi Memorial Lecture) that ‘In eve...

Rivers of Europe, Second Edition, presents the latest update on the only primary source of complete and comparative baseline data on the biological and hydrological characteristics of more than 180 of the highest profile rivers in Europe. With even more full-color photographs and maps, the book includes conservation information on current patterns...

Aim: Groundwater hosts a high diversity of metazoans that dwell in open spaces within the rock. That diversity makes an important, yet underestimated, contribution to freshwater biodiversity. Here, we briefly describe groundwater habitats, the composition and spatial distribution of groundwater metazoan assemblages, the characteristic traits of spe...

This is the introductory session to the Symposium 7 on Subterranean Life as part of the 18th International Congress of Speleology, Chambéry, France, 24-31 July 2022. The symposium call was broad. It welcomed proposals on a variety of topics including species inventory and description; biology, morphology, physiology, genetics and behavior of subter...

Groundwater presents the main source of potable water in Europe, but it is also a home to many specialized species. Current monitoring schemes of groundwater do not include the biotic component. Studies and conservation of groundwater fauna are challenging. Sampling techniques are demanding and due to low species detectability, multiple visits are...

Until the nineties. Gallasellus (lsopoda, Asellidae) was known from a single species, G. heilyi, which was known only from the type-locality, the subterranean River of Bataille (Gournay-Loize, Deux-Sevres, France). In 1992, Gallasellus was collected in a well in Oleron Island (Saint-Denis-d'Oleron, Charente-Maritime) at a distance of 100 km from th...

The waterlice (Asellidae, lsopoda) are one of the rare family of metazoans containing both a great number of surface aquatic species and subterranean aquatic species. This makes it an ideal case study for understanding eco-evolutionary processes taking place during the transition to groundwater habitats. Comparative studies can be performed on mult...

Identifying the relationships between morphology and trophic niche is at the core of functional morphology. Low resource diversity and fluxes of organic carbon are expected to constrain trophic specialisation of morphological structures because food resources are too scarce to promote trophic differentiation. However, species from low‐productivity...

Current standardized laboratory test protocols use model species that have limitations to accurately assess native species responses to stressors. We developed and tested a novel acute in situ protocol for testing field-collected organisms. We used Asellus aquaticus and NaCl as a reference toxicant to test for the effects of location (laboratory vs...

All organisms on Earth are exposed to low doses of natural radioactivity but some habitats are more radioactive than others. Yet, documenting the influence of natural radioactivity on the evolution of biodiversity is challenging. Here, we addressed whether organisms living in naturally more radioactive habitats accumulate more mutations across gene...

Five decades ago, a landmark paper in Science titled The Cave Environment heralded caves as ideal natural experimental laboratories in which to develop and address general questions in geology, ecology, biogeography, and evolutionary biology. Although the 'caves as laboratory' paradigm has since been advocated by subterranean biologists, there are...

All organisms on Earth are exposed to low doses of natural radioactivity but some habitats are more radioactive than others. Yet, documenting the influence of natural radioactivity on the evolution of biodiversity is challenging. Here, we addressed whether organisms living in naturally more radioactive habitats accumulate more mutations across gene...

Trophic selectivity has major influences on consumers’ fitness, stability of predator and prey populations, and nutrient fluxes in food webs. Trophic selectivity occurs when the relative abundances of resources in a consumer's diet differ from their relative abundances in the environment. This discrepancy between resources abundance and use has bee...

1. Storing, managing and sharing the ever-increasing amount of species occurrence data and biological vouchers is a cornerstone of biodiversity science. The convergence of morphology-and DNA-based methods for species delimitation has accentuated the need for optimizing laboratory workflow by generating new analytical processes, diversifying taxonom...

In light of recent alarming trends in human population growth, climate change, and other environmental modifications, a "Warning to humanity" manifesto was published in BioScience in 2017. This call reiterated most of the ideas originally expressed by the Union of Concerned Scientists in 1992, including the fear that we are "pushing Earth's ecosyst...

Janzen’s hypothesis (1967; American Naturalist) predicts that tropical habitats with reduced thermal seasonality would select for species with narrow thermal tolerance, thereby limiting dispersal among sites of different elevations showing little overlap in temperature. These predictions have so far been tested by confronting tropical and temperate...

The rate of molecular evolution varies widely among species. Life history traits have been proposed as a major driver of these variations. However, the relative contribution of each trait is poorly understood. Here, we test the influence of metabolic rate, longevity and generation time on the nuclear and mitochondrial synonymous substitution rates...

Decades of debates around the species problem have resulted in the emergence of a unified species concept with multiple criteria to delimit species taxa. Many biologists now agree to consider species as separately evolving segments of metapopulation lineages (i.e. the species concept), and to consider species taxa (i.e. the elementary units used in...

The rate of molecular evolution varies widely among species. Life history traits have been proposed as a major driver of these variations. However, the relative contribution of each trait is poorly understood. Here, we test the influence of metabolic rate, longevity and generation time on the nuclear and mitochondrial synonymous substitution rates...

Ecologists increasingly rely on molecular delimitation methods (MMs) to identify species boundaries, thereby potentially increasing the number of putative species because of the presence of morphologically cryptic species. It has been argued that cryptic species could challenge our understanding of what determine large-scale biodiversity patterns w...

The species concept is the cornerstone of biodiversity science and any paradigm shift in the delimitation of species affects many research fields. Many biologists now are embracing a new ‘species’ paradigm as separately evolving populations using different delimitation criteria. Individual criteria can emerge during different periods of speciation;...

In the last two decades, there has been a substantial progress in the availability of records for several subterranean taxa, as well as in mapping and statistical modeling of biodiversity patterns. Currently, there is still a large bias toward analyses of aquatic compared to terrestrial subterranean taxa. We provide the first global map of species...

• The hyporheic zone of rivers potentially acts as a dispersal corridor for groundwater organisms because it provides a spatially continuous interstitial habitat between isolated aquifers. Yet, the degree to which it can facilitate the movement of organisms has been hypothesized to vary in response to change in sediment regime, which determines cha...

The evolutionary origin of the striking genome size variations found in eukaryotes remains enigmatic. The effective size of populations, by controlling selection efficacy, is expected to be a key parameter underlying genome size evolution. However, this hypothesis has proved difficult to investigate using empirical datasets. Here, we tested this hy...

The field of stoichiogenomics aims at understanding the influence of nutrient limitations on the elemental composition of the genome, transcriptome and proteome. The 20 amino acids and the 4 nucleotides differ in the number of nutrients they contain, such as nitrogen (N). Thus, N limitation shall theoretically select for changes in the composition...

Mercantour National Park (France) is recognized as a highly heterogeneous region with extremely varied geology, geomorphology and climatology, resulting in an exceptional biodiversity. From a hydrogeological point of view, it is also an area organized into small and discontinuous aquifers, the obligate groundwater fauna of which (stygobionts) remai...

1. In river systems, aquatic invertebrate communities are surprisingly persistent over time and generally recover quickly from disturbances. Drift has long been viewed as the primary process promoting this resilience, and it plays a important role in predictive models of community composition and concepts in lotic ecology. More recently, other proc...

Aim Three broad mechanisms have been proposed to explain geographic variation in species range size: habitat area/heterogeneity, climate seasonality and long‐term climate variability. However, it has proved difficult to disentangle their relative role, particularly as temperature seasonality often covaries with the amplitude of long‐term temperatur...

The recognition of multi-causality and spatial non-stationarity in the determinants of large-scale biodiversity patterns requires to consider the role of multiple mechanisms, their interactions, and how these mechanisms vary in strength relative to each other across geographical space. Here, we challenge the view that historical climate stability p...

River landscapes are increasingly viewed as a collection of nested geomorphic features, the hydrological effects of which juxtapose to create a mosaic of aquatic habitat conditions. We examined how the combined hydrological influences of stream reaches and gravel bars affect the composition of hyporheic invertebrate assemblages along the longitudin...

Aim Disentangling the roles of the interacting processes that shape species' ranges requires independent measurements of dispersal, physiological traits and habitat use. Multifaceted approaches of range determinants are, however, still rare, despite the widespread recognition that correlative modelling approaches alone are not sufficient to underst...

1. Aquifers are considered to be controlled bottom-up because of their dependence on organic matter supply from surface ecosystems. Microorganisms are generally assumed to form the base of the food web and to respond strongly to organic matter supply. Although the bottom-up control of microorganisms by carbon sources has been well documented, the p...

Effective population size (Ne) is one of the most important parameters in, ecology, evolutionary and conservation biology; however, few studies of Ne in surface freshwater organisms have been published to date. Even fewer studies have been carried out in groundwater organisms, although their evolution has long been considered to be particularly con...

The potentially important role of northern microrefugia during post-glacial dispersal is challenging the view of Southern Europe as a refuge and source area of European biota. In groundwaters, large geographic ranges of presumably good dispersers are increasingly suspected to consist of assemblages of cryptic species with narrow ranges. Moreover, a...

Globalization and planetary environmental changes have stimulated the inventory of groundwater resources and biodiversity at continental and global scales but there has been no concurrent attempt to map the distribution of groundwater habitats even at continental scale. A vector version of the areal information contained in the international hydrog...

A key challenge for biologists is to document and explain global patterns of diversification in a wide range of environments. Here, we explore patterns of continental-scale diversification in a groundwater species-rich clade, the superfamily Aselloidea (Pancrustacea, Isopoda). Our analyses supported a constant diversification rate during most of th...

L'urbanisation amène à imperméabiliser de façon massive la surface du sol, et donc à créer des bassins d'infiltration pour les eaux de pluie. Ces bassins provoquent des transports importants (hydriques, soluté, chaleur) qui peuvent perturber et polluer la nappe sous-jacente. Le milieu étant généralement très hétérogène, le calage entre expérimentat...

The climate variability hypothesis assumes that the thermal tolerance breadth of a species is primarily determined by temperature variations experienced in its environment. If so, aquatic invertebrates living in thermally-buffered environments would be expected to exhibit narrow thermal tolerance breadths (stenothermy). We tested this prediction by...

Before the late 1970s, ecological studies were carried out mainly in the unsaturated zone of karst aquifers, particularly in caves. Because cave water bodies are exposed to the atmosphere, they are usually saturated with oxygen, dissolved oxygen (DO) was not measured routinely, and oxygen availability in subterranean bio- topes was rarely considere...

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...

Nowadays, stormwater infiltration systems are frequently used because of their ability to reduce flows and volumes in downstream sewers, decrease overflows in surface waters and make it possible to recharge groundwater. Moreover, they come in various forms with different uses. Despite these advantages the long term sustainability of these systems i...

# Purpose Best management practices encompass diverse artificial groundwater recharge (AGR) systems that heavily rely upon the capacity of the soil and vadose zone to retain large quantities of organic matter generated during stormwater runoff on urban catchments. However, the supply of stormwater-derived dissolved organic carbon (DOC) at the water...

Molecular tools have become prominent in ecology and evolution. A target of choice for molecular ecologists and evolutionists is mitochondrial DNA (mtDNA), whose many advantages have also convinced broad-scale, pragmatic programmes such as barcode initiatives. Of course, mtDNA is also of interest to human geneticists investigating mitochondrial dis...

Decreases in dissolved organic carbon (DOC) and dissolved oxygen (DO) with increasing depth below the groundwater table are often considered as evidence for aerobic respiration; however, they may reflect mixing of infiltrating water and groundwater. We found that groundwater DOC concentration was on average 0.3mgCl−1 higher and DO concentration 1.5...

Often out of reach and invisible, the life in subterranean waters remained for a long time secret or anecdotal. The stygobic fauna characterized by an exclusive life in subterranean waters is however well developed. Rhone-Alpes has around 130 species, mostly molluscs and crustaceans. Approximately 78 % of the current regional knowledge is post-1960...

Cave faunas : the emergence of an unknown world Often out of reach and invisible, the life in subterranean waters remained for a long time secret or anecdotal. The stygobie fauna characterized by an exclusive life in subterranean waters is however well developed. Rhone-Alpes has around 130 species, mostly molluscs and crustaceans. Approximately 78...

Publisher Summary The Rhone links several valleys and rivers from the upper Alps with the Mediterranean Sea. The Alps provided a strong economic and cultural unity to the Rhone throughout the last 1,000 years. Today, the Rhone River is a highly regulated river, viewed as a large waterway for commerce. It is a major source of nutrients and particula...

Groundwater warming below cities has become a major environmental issue; but the effect of distinct local anthropogenic sources of heat on urban groundwater temperature distributions is still poorly documented. Our study addressed the local effect of stormwater infiltration on the thermal regime of urban groundwater by examining differences in wate...

1. Using species distribution data from 111 aquifers distributed in nine European regions, we examined the pairwise relationships between local species richness (LSR), dissimilarity in species composition among localities, and regional species richness (RSR). In addition, we quantified the relative contribution of three nested spatial units – aquif...

1. A possible conservation strategy to minimise the risk of groundwater biodiversity loss due to human activities consists in designing a network of reserve areas at the continental scale that collectively include most groundwater species. To this end, we compared the efficiency of three area selection methods (species richness hotspots, endemism h...

1. This paper is a synthesis of a special issue on groundwater biodiversity with a focus on obligate subterranean species, the stygobionts. The series of papers constitutes a great leap forward in assessing and understanding biodiversity patterns because of the use of large quantitative data sets obtained over a broad geographic scale. They also re...

1. Estimates of species richness obtained from exhaustive field inventories over large spatial scales are expensive and time-consuming. For this reason, efficiency demands the use of indicators as ‘surrogates’ of species richness. Biodiversity indicators are defined herein as a limited suite of taxonomic groups the species richness of which is corr...

1. Relationships between the assemblage structure of stygobionts (i.e. obligate groundwater species) and habitat conditions in aquifers were explored in the French Jura based on 16 environmental variables and presence/absence data on stygobiotic species. The two data sets were simultaneously collected at a total of 269 sites. 2. The study aimed to...