Mickaël Hedde

French National Institute for Agriculture, Food, and Environment (INRAE) | INRAE · Department of Environment and Agronomy

Trait‐based approaches are increasingly being used to test mechanisms underlying species assemblages and biotic interactions across a wide range of organisms including terrestrial arthropods and to investigate consequences for ecosystem processes. Such an approach relies on the standardized measurement of functional traits that can be applied acros...

Soil invertebrates are assumed to play a major role in ecosystem dynamics, since they are involved in soil functioning. Functional traits represent one of the main opportunities to bring new insights into the understanding of soil invertebrate responses to environmental changes. They are properties of individuals which govern their responses to the...

Soil invertebrates are known to be much involved in soil behaviour and therefore in the provision of ecosystem services. Functional trait-based approaches are methodologies which can be used to understand soil invertebrates’ responses to their environment. They (i) improve the predictions and (ii) are less dependent on space and time. The way trait...

The aim of this study was to search for specific signatures of biogenic structures (i.e. earthworm casts, termite sheathings and mound material, and ant deposits) made by 15 species of soil engineers in a Colombian savanna. We thus investigated the organic matter (OM) biochemical composition of biostructures using near infrared spectroscopy (NIRS)...

We tested a trait-based approach to link a soil disturbance to changes in invertebrate communities. Soils and macro-invertebrates were sampled in sandy soils contaminated by long-term wastewater irrigation, adding notably organic matter and trace metals (TM). We hypothesized that functional traits of invertebrates depict ways of exposure and that e...

Soil organic matter (SOM) transformation processes are regulated by the activities of plants, microbes, and fauna. Compared with plants and microbes, effects of soil fauna are less understood because of their high taxonomic and functional diversity, and mix of direct and indirect effect mechanisms. Trait‐based approaches offer a generic perspective...

The trait-based approach is increasingly used for soil invertebrates. Complementary to the taxonomy based approach, the trait-based approach can provide a more mechanistic understanding of the responses of organisms to environmental disturbances and of their effects on soil functioning. However, the application of the trait-based approach across st...

The ongoing biodiversity crisis presents a complex challenge for ecological science. Despite a consensus on general biodiversity decline, identifying clear trends remains difficult due to variability in data, methodologies, and scales of analysis. To enhance our understanding of ongoing biodiversity changes and address discrepancies in biodiversity...

Recent climate and land use change, and pollution have led to concerning alterations in biodiversity and ecosystem functions, jeopardizing nature’s contributions to people. Mountainous regions are not immune to these threats, experiencing the impacts of global warming, increased recreational activities, and changes in agricultural practices. Levera...

Body size has been used thoroughly in arthropod ecology as a reliable trait to assess fitness responses to changes in environmental factors. Among these, spiders represent a large and diverse group, colonizing almost all terrestrial habitats. Here, we propose a review on intraspecific body size variation in arthropods over two main macroecological...

Soil and soil-biodiversity protection are increasingly important issues in environmental science and policies, requiring the availability of high-quality empirical data on soil biodiversity. Here we present a publicly available data warehouse for the soil-biodiversity domain, Edaphobase 2.0, which provides a comprehensive toolset for storing and re...

Plant protection products (PPPs) have historically been one of the classes of chemical compounds at the frontline of raising scientific and public awareness of the global nature of environmental pollution and the role of trophic interactions in shaping the impacts of chemicals on ecosystems. Despite increasingly strong regulatory measures since the...

Understanding the relative importance of biotic interactions, multiple environmental drivers, and neutral processes in shaping community diversity and composition is a central question for both theoretical and applied ecology. We analysed a dataset describing 125 earthworm communities sampled in 10 localities in French Guiana. DNA barcodes were use...

Tropical rainforests are among the most emblematic ecosystems in terms of biodiversity. However, our understanding of the structure of tropical biodiversity is still incomplete, particularly for certain groups of soil organisms such as earthworms, whose importance for ecosystem functioning is widely recognised. This study aims at determining the re...

Estimating the overall number of species for a given taxon is a central issue in ecology and conservation biology. It should be particularly topical in the case of soil organisms, which represent the majority of known species, but it still suffers from a considerable taxonomic knowledge deficit. We propose here an estimation of the global number of...

Soil unsealing, the process of removing the impermeable top layer of soil, is increasingly advocated by urban planning policies. The role of unsealed areas in biodiversity conservation, particularly soil biodiversity, remains strongly understudied and especially in understanding the recolonization dynamics of soil biodiversity in these new habitats...

From soil to freshwater ecosystems, decomposition can be conceived as the result of interactions between organic matter and a diversity of organisms. This function is driven in part by detritivores, invertebrates that feed on detritus or graze on its associated microbes and that have a significant but extremely variable contribution to decompositio...

The complexity of the opaque soil matrix is a major obstacle to studying the organisms that inhabit it. Fast technological progress now offers new possibilities for the monitoring of soil biodiversity and root growth, such as in situ soil imaging. This study presents the potential of soil imaging devices to investigate the temporal dynamics and spa...

Earthworms represent a crucial taxon in soil ecosystems in terms of biomass and ecological functions. Knowledge of their diversity is growing, but the understanding of the ecological and evolutionary mechanisms underlying this diversity and its distribution patterns remains poorly understood. This is partly due to a lack of community data available...

In recent decades, there has been growing interest in exploring the soil biota, highlighting the significance of soil organisms' networks in soil functioning. Here, we use a modeling approach to investigate how changes in cropping practices influence the soil food web dynamics and it relates to that of soil functioning. In an experimental trial, we...

Recent research on earthworms has shed light on their global distribution, with high alpha richness in temperate zones and high beta diversity in tropical areas. Climate and agricultural practices, notably plowing and conservation methods, were shown to strongly influence earthworm communities. However, data gaps persist in regions like North Austr...

In response to criticism of current specialized and input-intensive agriculture, diversified farming systems (DFS) have increased in popularity. The most advanced forms of DFS include perennial components (e.g., perennial crops, trees), functionally different plants and livestock, and landscape heterogeneity. These characteristics make it more diff...

Soil unsealing, the process of removing the impermeable top layer of soil, is increasingly advocated by urban planning policies. The role of unsealed areas in biodiversity conservation, particularly soil biodiversity, remains strongly understudied and especially in understanding the recolonization dynamics of soil biodiversity in these new habitats...

Copper-based plant protection products (PPPs) are widely used in both conventional and organic farming, and to a lesser extent for non-agricultural maintenance of gardens, greenspaces, and infrastructures. The use of copper PPPs adds to environmental contamination by this trace element. This paper aims to review the contribution of these PPPs to th...

Global changes call for more nature-based solutions, especially in nature conservation involving ecological restoration. Current methods essentially based on civil engineering are both expensive and costly in non-renewable energy consumption and pollution terms. The non-sustainability of these techniques is leading to the direct use of certain spec...

Southern France has been highlighted as an important hotspot of earthworm diversity mostly by the work of Marcel Bouché, who sampled more than 1300 localities in mainland France including Corsica in the 1960s. We resampled some of the Bouché's localities and conducted molecular phylogenetic analyses. It leads to the identification of a new Lumbrici...

Neonicotinoids are the most widely used class of insecticides in the world, but they have raised numerous concerns regarding their effects on biodiversity. Thus, the objective of this work was to do a critical review of the contamination of the environment (soil, water, air, biota) by neonicotinoids (acetamiprid, clothianidin, imidacloprid, thiaclo...

Our knowledge of the factors influencing the distribution of soil organisms is limited to specific taxonomic groups. Consequently, our understanding of the drivers shaping the entire soil multitrophic network is constrained. To address this gap, we conducted an extensive soil biodiversity monitoring program in the French Alps, using environmental D...

Although soil ecology has benefited from recent advances in describing the functional and trophic traits of soil organisms, data reuse for large-scale soil food-web reconstructions still faces challenges. These obstacles include: (1) most data on the trophic interactions and feeding behaviour of soil organisms being scattered across disparate repos...

Pour répondre au besoin de connaissances sur la biodiversité des sols, nous explorons la possibilité d’adosser un suivi de la biodiversité des sols au Réseau de Mesures de la Qualité des Sols (RMQS). Ce couplage a pour objectif de bénéficier du caractère opérationnel du RMQS et de croiser les informations sur la biodiversité avec les données déjà d...

The three main ecological categories of earthworms (anecic, endogeic, epigeic) are often used as proxies for functional groups. This is troublesome since they were not designed for this purpose and thus the relevance of such a use was never tested nor proven. How earthworms influence the different soil functions is tightly linked to their bioturbat...

The genus Aporrectodea includes some of the most conspicuous earthworm species, but its taxonomic history is among the most complex within the family Lumbricidae. Molecular phylogenetic studies have produced some advances by assigning former Aporrectodea species to other monophyletic clades and by detecting species level lineages within the cosmopo...

Although soil ecology has benefited from recent advances in describing the functional and trophic traits of soil organisms, data reuse for large-scale soil food-web reconstructions still faces challenges. These obstacles include: (1) most data on the trophic interactions and feeding behaviour of soil organisms being scattered across disparate repos...

There is growing interest in using the ecosystem services framework for environmental risk assessments of chemicals, including plant protection products (PPPs). Although this topic is increasingly discussed in the recent scientific literature, there is still a substantial gap between most ecotoxicological studies and a solid evaluation of potential...

Our knowledge of the factors influencing the distribution of soil organisms is limited to specific taxonomic groups. Consequently, our understanding of the drivers shaping the entire soil food web is constrained. To address this gap, we conducted an extensive soil biodiversity monitoring program in the French Alps, using environmental DNA to obtain...

Agroecology practices can induce profound positive changes in soil physical and chemical properties, and inevitably influence soil biological properties and soil functioning. However, we still lack understanding of how soil biodiversity responds to agroecology practices and to what extent such practices, alone or combined, can be beneficial for soi...

Preservation of biodiversity and ecosystem services is critical for sustainable development and human well-being. However, an unprecedented erosion of biodiversity is observed and the use of plant protection products (PPP) has been identified as one of its main causes. In this context, at the request of the French Ministries responsible for the Env...

Agroecosystems are facing new challenges in the context of a growing and increasingly interconnected human population, and a paradigm shift is needed to successfully address the many complex questions that these challenges will generate. The transition to providing multiple services within an agroecosystem is a starting point for heightened multifu...

Since the 18th century, several taxonomists have contributed to knowledge of the French earthworm fauna, one of the best-known earthworm communities in Europe, with 164 species currently described. Surprisingly, new species keep being added constantly, even large ones, which are usually the first to be described. The recent discovery of six undescr...

We launch an initiative to build a collection of pictures of earthworm species with good identification, both in the field and in the lab. We use iNaturalist to reach non scientists and also to improve iNat's computer vision engine.

Agroecosystems are facing new challenges in the context of a growing and increasingly interconnected human population, and a paradigm shift is needed to successfully address the many complex questions that these challenges will generate. The transition to providing multiple services within an agroecosystem is a starting point for heightened multifu...

The taxonomy of earthworms has been riddled by instability, lack of systematically useful characters, and lax diagnoses of some genera. This has led to the use of some genera such as Allolobophora Eisen, 1874 as taxonomic wastebaskets, blurring their evolution and biogeographical history. The implementation of molecular techniques has revolutionize...

Scherotheca Bouché, 1972 is a highly diverse genus of Lumbricidae Rafinesque-Schmaltz, 1815, broadly distributed from Northern Italy and Corsica Island to the Pyrenees and Northeastern Iberian Peninsula. A recent survey of earthworm species diversity in Corsica resulted in the identification of 12 operational taxonomic units (OTU) within Scherothec...

Collembola are a widespread class of arthropods that live mostly in the soil or on its surface. Communities of Collembola have notably been used as bioindicators of several environmental factors such as pollution or land use. Recently, they have also opened perspectives for monitoring the effects of projected climate change on soil biodiversity, in...

The study of elevational diversity gradients is a central topic in biodiversity research. In this study, we tested for the effect of climate, resource quality and habitat heterogeneity on earthworm communities along an altitudinal gradient and around the treeline in the French Alps. Earthworm communities and environmental properties (i.e. climate,...

Although DNA barcodes-based operational taxonomic units (OTUs) are increasingly used in earthworm research, the relative efficiency of the different methods available to delimit them has not yet been tested on a comprehensive dataset. For this study, we used three datasets containing 651, 2304 and 4773 COI barcodes of earthworms from French Guiana,...

Background and Aims: Agroecology practices can induce profound changes in soil inevitably influencing soil biological properties and soil functioning. However, we still lack understanding of how soil biodiversity responds to agroecology practices and to what extent such practices, alone or combined, can be beneficial for soil functioning. Understand...

Available studies of the earthworm fauna of Corsica reported a total of 36 species, but this regional diversity is probably underestimated considering the relatively modest sampling efforts achieved so far. We conducted a sampling campaign in the context of the program “Our Planet Reviewed”, with the aim to increase sampling coverage and to analyze...

The investigation of the complicated underground life via automatic technique is in high demand in recent days. Using Convolutional Neural Network (CNN) to detect soil in- vertebrates is an interesting approach, although most studies on the topic have focused on other solutions. The creation of state-of-the-art technique through this work will be a...

The investigation of the complicated underground life via automatic technique is in high demand in recent days. Using Convolutional Neural Network (CNN) to detect soil invertebrates is an interesting approach, although most studies on the topic have focused on other solutions. The creation of state-of-the-art technique through this work will be a s...

Earthworms play a key role in soil carbon mineralization, but their effect is highly uncertain and suspected to vary as a function of several factors, particularly the earthworm density and time from earthworm inoculation. We conducted a meta-analysis considering these factors based on 42 experiments comparing carbon mineralization in the absence a...

Les sols hébergent une importante biodiversité. Ils sont essentiels pour nourrir l'humanité et jouent un rôle fondamental dans les cycles biogéochimiques de la planète. Alors qu'à l'échelle du globe, un tiers des sols sont dégradés, comprendre les processus écologiques qui s'y déroulent pour mieux les préserver et les restaurer est un enjeu majeur....

Les catégories écologiques de vers de terre définies par Marcel Bouché sur les vers de terre français entre 1971 et 1977 ont eu un succès mondial et sont maintenant utilisées par tous les auteurs de tous les continents. Cependant, deux glissements de sens et d'usage peuvent être décelés dans la littérature scientifique. Le premier est que la plupar...

Bacterial-feeding nematodes are abundant soil animals regulating microbial communities and enhancing plant nutrition and growth. However, the biological metrics driving the variable within-trophic group effects of these organisms on soil and plant functions are not yet identified. In this study, we determined the effects of eight bacterial-feeding...

Classifying organisms has a wide use and a long history in ecology. However, the meaning of a 'group of or-ganisms' and how to group organisms is still the subject of much theoretical and empirical work. Achieving this long quest requires simplifying the complexity of species niches for which relevant morphological, behavioural, biochemical or life...

Due to their high structural and functional diversity, soil invertebrates are crucial for ecosystem functioning and its stability. This diversity is reflected not only in the multitude of quantitative and qualitative studies, but also in the range of existing vocabularies of characters and character states for functional soil biodiversity. Data min...

Les sols hébergent une importante biodiversité. Ils sont essentiels pour nourrir l'humanité et jouent un rôle fondamental dans les cycles biogéochimiques de la planète. Alors qu'à l'échelle du globe, un tiers des sols sont dégradés, comprendre les processus écologiques qui s'y déroulent pour mieux les préserver et les restaurer est un enjeu majeur....