Laurent Larrieu

• PhD
• L’Institut national de la recherche agronomique (Toulouse)

The present study aims to challenge and refine the existing paradigm of relict primary forests located in temperate Europe and to clarify their long-term dynamics. We focussed on the beech-fir (Fagus sylvatica L.-Abies alba Mill.) forest located in the montane belt of Romanian Carpathian Mountains and French Central Pyrenees. A hierarchical samplin...

Between 2016 and 2024, as part of several research projects on forest history in the mountain belt of the central French Pyrenees, we cored 360 living trees at breast height, including 309 silver fir (Abies alba Mill. 1768) and 51 European beech (Fagus sylvatica L. 1753), using an increment drill. In addition, 64 cross-sections of beech stems were...

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Sustainable forest management aims to integrate biodiversity conservation while maintaining economic and social functions. However, direct biodiversity monitoring is usually costly and time-consuming, making structural indicators a valuable tool for integrating conservation criteria into forest management. We used the ten habitat structural variabl...

https://bioarcheo.hypotheses.org/3292

Ecological processes associated to rare events are hard to estimate from individual empirical studies. A typical example in forest ecology is the formation of tree-related microhabitats (TreMs) on trees. TreMs are key features for forest biodiversity, and their accumulation rate is a key information to design integrative management strategies. Many...

Tree-related Microhabitats (TreMs) are of prime concern for biodiversity since they host thousands of taxa. TreMs are discrete habitat patches borne by trees and cover a wide range of lifespans, from days to decades to centuries. The taxa associated with such discrete and sometimes highly ephemeral habitat patches are likely to be sensitive to spat...

Retention forestry emerged as a means of ameliorating the biodiversity impacts of clearcutting 30 years ago and has become an integrated part of forest management in many countries. Nowadays, there is still an increasing need to assess to what extent retention trees contribute to biodiversity in production forests. We used tree-related microhabitat...

Key message This article presents ring width chronologies derived from samples extracted from historical timber buildings in the French central Pyrenees. Two chronologies for fir ( Abies alba Mill.) were dated for two periods: 1446–1655 and 1679–1952 AD. These chronologies are suitable for dendroarchaeological and paleoenvironmental studies, or for...

The second edition of the field guide to tree-related microhabitats includes the latest scientific knowledge on associated species and contains an appendix of photographs of all 52 types of tree-related microhabitats, including five new ones since the first edition. This guidebook may be downloaded at the following link: www.wsl.ch/fg-trems Sugges...

The hyperdiverse wood‐inhabiting fungi play a crucial role in the global carbon cycle, but often are threatened by deadwood removal, particularly in temperate forests dominated by European beech (Fagus sylvatica) and Oriental beech (Fagus orientalis). To study the impact of abiotic drivers, deadwood factors, forest management and biogeographical pa...

This article tracks changing conceptions of time in European forest science over recent decades, and accounts for how they can affect forest conservation and management. Through semiotic analysis of 62 peer-reviewed articles published in ecology and forestry, we (1) characterize the temporal features of old European forests as they evolve over our...

Ancient and Mature Forests (AMFs) represent only a tiny fraction of Europe's forests. However, these forests are home to a unique biodiversity, thanks to a wide variety of habitats and a high degree of naturalness. These AMFs’ ecosystem qualities, resulting from long periods without human intervention, do not mean that AMFs have not been exploited...

Tree-related microhabitats (TreMs) describe the microhabitats that a tree can provide for a multitude of other taxonomic groups and have been proposed as an important indicator for forest biodiversity (Asbeck et al., 2021). So far, the focus of TreM studies has been on temperate forests, although many trees in the tropics harbour exceptionally high...

Dans ce numéro de mars 2024, Archéologia vous propose un grand dossier sur l'archéologie de la forêt. Science très récente et pluridisciplinaire, elle considère le couvert forestier en lui-même comme un objet d'étude aux riches enseignements...

A tree-related microhabitat (abbreviated as TreM) is a morphological feature present on a tree, which is used by sometimes highly specialised species during at least one part of their life cycle. These features may serve as shelters, breeding spots, or crucial hibernation or feeding places for thousands of species. Each TreM provides very specific...

Background. Broad-scale monitoring of arthropods is often carried out with passive traps (e.g., Malaise traps) that can collect thousands of specimens per sample. The identification of individual specimens requires time and taxonomic expertise, limiting the geographical and temporal scale of research and monitoring studies. DNA metabarcoding of bul...

Tree-related microhabitats (TreMs) provide a quantitative indicator of habitat heterogeneity in forests, including beech (Fagus) forests. However, systematic analyses of the factors driving TreM diversity and composition in Fagus sylvatica and F. orientalis forests are lacking. In this study, the TreMs of beech forests on 203 plots of 22 forest sit...

Forest decline caused by climate change has been a growing challenge for European foresters for decades. The accumulation of tree-related microhabitats (TreMs) and deadwood during decline can enhance stand structural heterogeneity and provide crucial habitat features for many forest ecological guilds. We analysed changes in deadwood and TreM assemb...

Riparian forests are considered as complex and biologically rich habitats. They play a crucial role for biodiversity conservation, in particular in landscapes under strong management pressure. Tree-related microhabitats (TreMs) support a wide array of biodiversity and some authors have suggested using them as indirect biodiversity indicators in for...

Agriculture and forestry cover more than 75% of Europe, and invertebrate pests are a costly challenge for these two economic sectors. Landscape management is increasingly promoted as a solution to enhance biological pest control, but little is known on its effects on adjacent crop fields and woodlands. This study aims to explore the effect of the p...

Les coupes sanitaires sont utilisées pour limiter l’impact sanitaire et économique des dépérissements forestiers. Dans cette revue de la littérature, nous avons examiné l’impact de ces coupes sur les services écosystémiques associés à la résilience des écosystèmes forestiers. Les coupes sanitaires affectent les communautés d’espèces forestières en...

The species‐energy hypothesis predicts increasing biodiversity with increasing energy in ecosystems. Proxies for energy availability are often grouped into ambient energy (i.e., solar radiation) and substrate energy (i.e., non‐structural carbohydrates or nutritional content). The relative importance of substrate energy is thought to decrease with i...

Assessing the impacts of natural disturbance on the functioning of complex forest systems are imperative in the context of global change. The unprecedented rate of contemporary species extirpations, coupled with widely held expectations that future disturbance intensity will increase with warming, highlights a need to better understand how natural...

Protecting structural features, such as tree‐related microhabitats (TreMs), is a cost‐effective tool crucial for biodiversity conservation applicable to large forested landscapes. Although the development of TreMs is influenced by tree diameter, species, and vitality, the relationships between tree age and TreM profile remain poorly understood. Usi...

Background Broad-scale monitoring of arthropods is often carried out with passive traps ( e.g . Malaise traps) that can collect thousands of specimens per sample. The identification of individual specimens requires time and taxonomic expertise, limiting the geographical and temporal scale of research and monitoring studies. DNA metabarcoding of bul...

Tree to tree interactions are important structuring mechanisms for forest community dynamics. Forest management takes advantage of competition effects on tree growth by removing or retaining trees to achieve management goals. Both competition and silviculture have, thus, a strong effect on density and distribution of tree related microhabitats whic...

L’étude des systèmes écologiques est souvent rendue difficile car certaines composantes échappent à une observation parfaite, comme les trajectoires d’animaux en mouvement ou la banque de graines des plantes. La modélisation statistique permet de traiter efficacement ces composantes cachées en utilisant le cadre des variables latentes, qui permet d...

Context Many forest ecosystems around the world are facing increasing drought-induced dieback, causing mortality patches across the landscape at multiple scales. This increases the supply of biological legacies and differentially affects forest insect communities. Objectives We analysed the relative effects of local- and landscape-level dieback on...

Sustainable management of forest ecosystems requires the use of reliable and easy to implement biodiversity and naturalness indicators. Tree-related microhabitats (TreMs) can fulfill these roles as they harbor specialized species that directly or indirectly depend on them, and are generally more abundant and diverse in natural forests or forests un...

Tree-related microhabitats (TreMs) have been identified as key features for forest-dwelling taxa and are often employed as measures for biodiversity conservation in integrative forest management. However, managing forests to ensure an uninterrupted resource supply for TreM-dwelling taxa is challenging since TreMs are structures with a limited avail...

In Europe, forest management has controlled forest dynamics to sustain commodity production over multiple centuries. Yet over‐regulation for growth and yield diminishes resilience to environmental stress as well as threatens biodiversity, leading to increasing forest susceptibility to an array of disturbances. These trends have stimulated interest...

Through a reconstruction of the chronology and intensity of charcoal-making activities, this paper re-opens the debate about the supposed impact of the charcoal iron industry on forest cover in the French Pyrenees. This reappraisal focuses on the former territory of the communities of Haut-Vicdessos valley. This more refined chronology, based on th...

La protection d’espaces forestiers en libre évolution, définie formellement pour la première fois dans le parc national des Cévennes, s’inscrit dans la continuité d’une longue histoire de préservation des espaces naturels. Ces forêts couvrent en 2022 environ 41 000 ha en métropole (0,24 % des forêts), principalement grâce aux réserves biologiques i...

Le regard de Joseph Garrigue : chronique d’une observation naturaliste sensible. Le regard de Laurent Larrieu : des espaces forestiers en libre évolution : Pourquoi ? Où ? Comment ? Que dit la science ? Outre leur grande valeur patrimoniale intrinsèque, les forêts faiblement anthropisées offrent un refuge à la biodiversité spécifique des milieux fo...

Isolated trees are increasingly recognised as playing a vital role in supporting biodiversity in agricultural landscapes, yet their occurrence has declined substantially in recent decades. Most bats in Europe are tree-dependent species that rely on woody elements in order to persist in farmlands. However, isolated trees are rarely considered in con...

En aquest document s'estableix una metodologia per calcular l'impacte de la gestió forestal multifuncional en tres factors clau de la mitigació i l'adaptació al canvi climàtic a la Mediterrània: el carboni, l'aigua i la biodiversitat. En aquesta primera versió, l'impacte de la gestió en el balanç de carboni s'ha obtingut per a les principals conífe...

Effects of forest management on forest biodiversity have received increasing attention in both research and forestry practice. Despite advances in technology, monitoring of biodiversity remains time and cost-intensive and requires specific taxonomic expertise. In forest management, however, there is increasing interest and need to integrate biodive...

Structural equation models (SEMs) provide a statistical framework for compact representations of theories concerning the relations between components in a socio‐ecosystem. In this chapter, the authors show how SEMs maintain statistical power in cases with large numbers of observed variables, combining variables into groups and linking them to subja...

Species richness, abundance and biomass of insects have recently undergone marked declines in Europe. We metabarcoded 211 Malaise-trap samples to investigate whether drought-induced forest dieback and subsequent salvage logging had an impact on ca. 3000 species of flying insects in silver fir Pyrenean forests. While forest dieback had no measurable...

Centuries of charcoal making has profoundly shaped European mountain forest ecosystems. However, it remains difficult to assess this impact due to a lack of knowledge about the full operational sequence and related silvicultural systems. To accurately reconstruct such practices and shed light on the resulting legacies, we carried out an interdiscip...

The retention of trees bearing tree‐related microhabitats (TreMs) has become an important means of conserving biodiversity in production forests. However, we lack estimates of TreM formation rates and evidence on factors driving TreM formation. Based on the observation of 80,099 living trees from 19 species groups in Europe and Iran, we estimated t...

Context: Forest ecosystems worldwide are facing increasing drought-induced dieback, causing mortality patches across the landscape at multiple scales. This increases the supply of biological legacies and differentially affects forest insect communities. Objectives: We analysed the relative effects of local- and landscape-level dieback on local sapr...

Afin d’évaluer la capacité d’accueil des ripisylves pour la biodiversité, nous proposons un nouvel indice tenant compte des dimensions longitudinale et transversale de l’hydrosystème : l’Indice de Biodiversité et de Connectivité des Ripisylves (IBCR). Constitué de 15 facteurs renseignant des critères liés au peuplement et à sa gestion, au contexte...

Primary forests, defined here as forests where the signs of human impacts, if any, are strongly blurred due to decades without forest management, are scarce in Europe and continue to disappear. Despite these losses, we know little about where these forests occur. Here, we present a comprehensive geodatabase and map of Europe’s known primary forests...

Reconnaître les arbres-habitats grâce à l’application habitat.sylvotheque.ch Découvrir, rechercher et identifier les dendromicrohabitats portés par les arbres grâce à des photos à 360° prises en forêt: habitat.sylvotheque.ch est une plateforme informatique, disponible en français, en allemand et en anglais, pour apprendre à reconnaître les dendromi...

Despite the key importance of the landscape matrix for bats, we still not fully understand how the effect of forest composition interacts at combined stand and landscape scales to shape bat communities. In addition, we lack detailed knowledge on the effects of local habitat structure on bat-prey relationships in forested landscapes. We tested the a...

A Tree-related Microhabitat (TreM) is a distinct, well-delineated morphological singularity occurring on living or standing dead trees, which constitutes a crucial substrate or life site for various species. TreMs are widely recognized as key features for biodiversity. Current TreM typology identifies 47 TreM types according to their morphology and...

The geographical distributions of species associated with European temperate broadleaf forests have been significantly influenced by glacial–interglacial cycles. During glacial periods, these species persisted in Mediterranean and extra-Mediterranean refugia and later, during interglacial periods, expanded northwards. The widespread saproxylic beet...

Marked decline in insect species richness, abundance and biomass have recently been quantified in Europe. We metabarcoded 224 Malaise-trap samples to investigate whether drought-induced forest dieback and subsequent salvage logging have an impact on flying insects ( ca . 3000 insect species) in silver fir Pyrenean forests. We found no evidence that...

China has recently announced a reform of forestry policy, with a major goal being to transform from plantation to heterogeneous forests, which have higher resistance to pests and disease and house more biodiversity. One driver of reform is increased intensity and frequency of pest-induced tree-dieback events. To inform management, we ask what effec...

Natural disturbances are major drivers of forest dynamics. However, in the current context of anthropogenic global warming, shifts in disturbance regimes are expected. Natural disturbances usually leave biological or structural legacies which are important for early-successional species. Nevertheless, these legacies are usually eliminated by forest...

This guidebook may be downloaded at the following link: www.wsl.ch/fg-trems Suggested reference for bibliography: Bütler, R.; Lachat, T.; Krumm, F.; Kraus, D.; Larrieu, L., 2020: Field Guide to Tree-related Microhabitats. Descriptions and size limits for their inventory. Birmensdorf, Swiss Federal Institute for Forest, Snow and Landscape Research W...

Biodiversity is of great importance for the functioning of the forest ecosystem. Habitat trees are a key component of forest biodiversity. Experts from Europe have developed a typology of tree-related microhabitats, small life-sites borne by some trees, which are indispensable for thousands of specialised organisms. The uniform use of the forms, gr...

La capacité d’accueil pour la biodiversité ordinaire des formations forestières dominées par le chêne faginé (Quercus faginea Lam.) a été évaluée dans l’Aurès en mettant en application l’Indice de biodiversitépotentielle (IBP), testé pour la première fois dans les forêts algériennes. Les diagnostics IBP ont été réalisés sur 12 placettes couvrant un...

L’IBP est un outil pour aider les gestionnaires forestiers à intégrer plus aisément la biodiversité taxonomique ordinaire1 dans leur gestion courante. Depuis sa création en 2008, l’IBP s’est développé grâce à un programme original de Recherche & Développement mené par le CNPF et l’INRAE, avec la participation financière du ministère de la Transitio...

Cet article constitue un retour d’expérience de gestion à la fois intégrative et adaptative, menée depuis 2005 sur les 17 000 hectares d’une forêt de l’État de Bavière. L’entreprise forestière d’État Ebrach gère une forêt domaniale dominée par le Hêtre, dans la région du Steigerwald. Tout en générant environ un million d’euros de bénéfice annuel, s...

• Global change scenarios project drastic modifications in tree species range and an increase in exotic tree plantations. Subsequent tree species substitutions may alter habitat conditions for biodiversity. • We measured substitutability between tree species for early deadwood colonisers, through a sentinel log approach, i.e. through the experiment...

La biodiversité joue un rôle important dans le fonctionnement des écosystèmes forestiers. Les arbres-habitats sont des éléments clés pour les espèces vivant en forêt. Des spécialistes européens ont élaboré une typologie détaillée des dendromicrohabitats, petits milieux de vie portés par les arbres et qui sont indispensables à des milliers d’organis...

Cette publication peut être téléchargée à l'adresse suivante: www.wsl.ch/bmh-taschenfuehrer Citation recommandée: Bütler, R.; Lachat, T.; Krumm, F.; Kraus, D.; Larrieu, L., 2020: Guide de poche des dendromicrohabitats. Description et seuils de grandeur pour leur inventaire. Birmensdorf, Institut fédéral de recherches WSL. 59 p.

Die Biodiversität ist für das Funkti­onieren des Waldökosystems von grosser Bedeutung. Habitatbäume sind eine Schlüsselkompo­nente der Waldbiodiversität. Fach­leute aus Europa erarbeiteten eine Typologie der Lebensräume (soge­nannte Baummikrohabitate), die auf Bäumen vorkommen und für Tau­sende von spezialisierten Lebewe­sen unentbehrlich sind. Die...

Dieser Taschenführer beschreibt die 47 Typen von Baummikrohabitaten, die in 15 Gruppen und 7 Formen unterteilt sind. Der Taschenführer ist eine Beilage zum Merkblatt für die Praxis 64 «Habitatbäume kennen, schützen und fördern». Die einheit­liche Verwendung der so definierten Formen, Gruppen und Typen dieser Baummikrohabitate erleichtert die Umsetz...

Primeval forests in the temperate zone exist only as a few remnants, but theses serve as important reference areas for conservation. As key habitats, tree-related microhabitats (TreMs) are of intense interest to forest ecologists, but little is known about their natural composition and dynamics in different tree species. Beech forms a major part of...

Co-éditeurs scientifiques : Pescini, Valentina, Panetta, Alessandro, Py-Saragaglia, Vanessa

Ecological indicators based on measurements made by individual observers often include extra noise associated with the observer herself (observer effect). The literature on this subject has used a variety of analytical tools to account for this variation, but few analyses have used a hierarchical statistical model approach that can account for the...

Metabarcoding increases the taxonomic resolution and geographic scale at which researchers can assess the impacts of climate change on insect communities in forests

To encourage forest managers to use biodiversity indicators in their work, providing environmental variables that depict species habitats, have well-calibrated and strong relationships with biodiversity and are easy to routinely record would be a step forward. The Index of Biodiversity Potential (IBP) is a rapid habitat assessment method widely use...

In most European temperate forests, the heavy harvesting of low-quality wood for energy, a low minimum harvest diameter and a short rotation period, result in the limited deadwood resources. However, areas are being set aside in managed forests to restore deadwood levels. Coppice-with-standards is a silvicultural method characterized by periodic lo...

Aim Beech forests comprise a globally unique temperate forest type in Europe. The dominance of beech in these forests developed during the ongoing post‐glacial northward re‐colonization, concurrently with intensified forest use by humans. We investigated how these two processes together with climate shaped the patterns of functional diversity of tw...

Aim The tinder fungus Fomes fomentarius is a pivotal wood decomposer in European beech Fagus sylvatica forests. The fungus, however, has regionally declined due to centuries of logging. To unravel biogeographical drivers of arthropod communities associated with this fungus, we investigated how space, climate and habitat amount structure alpha and b...

Tree-related microhabitats (TreMs) are important features for the conservation of biodiversity in forest ecosystems. Although other structural indicators of forest biodiversity have been extensively studied in recent decades, TreMs have often been overlooked, either due to the absence of a consensual definition or a lack of knowledge. Despite the i...

A partir de l’observation de près de 4 000 sapins pectinés (Abies alba) dans les Pyrénées, une récente étude montre d’une part que, contrairement aux idées reçues, les arbres les plus gros ne sont pas nécessairement les plus dépérissants ou les plus enclins à dépérir ; que d’autre part, entre le gui (Viscum album subsp. abietis) et le dépérissement...

Cross-taxon surrogacy (between-taxon similarities in species patterns) can help conservation biologists to design simplified, standardized and efficient tools for biodiversity monitoring. Our study aims to identify potential sets of indicator taxa to be recommended in temperate forests. We focused on nine forest taxa: vascular plants, bryophytes, s...

Marteloscopes are multifunctional training tools that can create a better understanding of forest management and have been developed as didactic tools for virtual tree selections. With this paper the authors provide explanatory information on the more than 40 Marteloscopes that were established in the course of the project Integrate+. It presents t...

The sustainable multifunctional management of forests entails taking into account biodiversity. Biodiversity has various facets all of which are difficult to apprehend, hence the usefulness of proposing relevant, easy-to-use tools such as the Index of Biodiversity Potential (IBP). The IBP has been worked out for France’s European mainland forests,...