Les ouvrages de génie végétal représentent des solutions alternatives ou complémentaires au génie civil pour stabiliser les berges de cours d'eau. Ces techniques sont encore peu appliquées aux Antilles et les rares ouvrages réalisés jusqu’à présent intégraient majoritairement des espèces allochtones alors que la richesse de la flore locale constitue un patrimoine exceptionnel. Mais, le manque de connaissance sur les capacités des espèces indigènes constitue un frein majeur au développement des techniques de génie végétal. Cet article présente les résultats d’une série d’expérimentations effectuées dans le cadre du projet « Protéger », qui vise à développer et promouvoir le génie végétal aux Antilles. Des mesures ex situ, conduites sur une sélection de vingt-six espèces ripicoles (douze espèces ligneuses, trois semi ligneuses, deux arbrisseaux, cinq herbacées et quatre fougères) ont permis de définir leurs caractéristiques biotechniques d’intérêt pour le génie végétal (capacité de propagation, croissance, longueur et diamètre des racines, rapport biomasse racine/tige). Les espèces indigènes les mieux adaptées aux principales techniques du génie végétal ont été identifiées à l’aide d’une méthode d’analyse multicritère adaptée, fournissant ainsi les éléments nécessaires à l’orientation des préconisations opérationnelles. Ces résultats participeront au développement du génie végétal aux Antilles.

Scouring at the toe of riverbanks drives bank instability and is a leading cause of failure of streambank protection structures. It affects both civil engineering and soil and water bioengineering structures, and is particularly pronounced in meanders, where channel curvature generates helicoidal secondary flows. Despite numerous studies on scouring and filling processes, the combined influence of hydrodynamic, morphological and ecological controls remains incompletely understood. As a result, prediction of scour depths at riverbank toe are imprecise. This study presents a new independent field dataset of 116 meander scour holes across diverse geomorphological contexts. For each site and under field flow conditions, scour depths, ecological and physical measurements were collected. First, we analysed how scour depth was linked to dimensionless physical variables and the presence of vegetation to better understand the drivers of scour development in meandering rivers. Second, we evaluated the performance of empirical equations calculating meander scour depth by comparing predicted and observed values. We also assessed their robustness against our dataset and previously published data. The results revealed that hydraulic and geomorphological characteristics combine to influence scouring in meanders, and that the curvature-to-width ratio is a key parameter. Vegetation also exerts a measurable influence on scour depths. The comparison with predictions revealed the limitations of empirical field-based approaches, which generally reflect instantaneous rather than peak scour conditions. Nonetheless, two equations performed well as envelope predictors. Adjustments are suggested to refine their applicability under specific conditions and to help improve the design of riverbank stabilisation projects in meandering rivers.

Fascines are among the oldest bioengineering structures used to control erosion and stabilize riverbanks, slopes, and incised landforms. While their historical use dates back centuries, the diversity of fascine-based techniques has often been overlooked or poorly described in the contemporary ecological restoration literature. This article synthetizes literature ranging from early civil engineering treatises (18th-19th centuries) to contemporary scientific studies, including historical texts, technical manuals, monitoring reports, and peer-reviewed articles. We propose a comprehensive typology of the main fascine techniques according to their position and function (streambank, riverbed, slope), and analyze their structural characteristics, operating mechanisms, and ecological and technical outcomes. The synthesis highlights that toe and bank fascines are most effective under low to moderate energy conditions when properly anchored and combined with complementary vegetation techniques, whereas transverse and drainage fascines are more context-dependent and prone to failure if hydrological dynamics are insufficiently considered. Across techniques, performance appears primarily controlled by the match between hydraulic and ecological conditions and design configuration, with misalignment frequently leading to structural failure or limited ecological functionality. Common failure modes include toe scour, inadequate anchorage, poor plant establishment, and sediment bypass. A synthesis table summarizes contexts of use, dominant hydraulic mechanisms, ecological benefits, and typical failure modes, providing a decision-support tool for practitioners. Overall, longitudinal structures (e.g. toe and slope fascines) tend to provide more predictable stabilization outcomes, while transverse and in-channel structures generate higher ecological diversity but also greater uncertainty in performance. More broadly, the review highlights a trade-off between immediate mechanical stability and long-term ecological integration, depending on the type of fascine and implementation context.This review demonstrates that while fascines can deliver both immediate erosion control and long-term ecological benefits, their success strongly depends on site-specific hydromorphological conditions, species selection, and design choices. The paper also identifies key knowledge gaps, notably the lack of quantitative performance data and standardized monitoring, and outlines priorities for future research and practice.

Snowmaking reservoirs have rapidly expanded across alpine regions. These structures are often very mineral, made of riprap, concrete and geomembrane, and generally host little or no vegetation. Yet, their potential to host littoral vegetation remains poorly documented. These artificial reservoirs often act as ecological traps due to steep, unvegetated banks and inverted hydroperiods. This study experimentally assessed (i) the feasibility of littoral revegetation using coir macrophyte rolls as a Nature-based Solution in a French Alps snowmaking reservoir at high elevation, and (ii) whether such revegetation can initiate successional trajectories comparable with the regional species pool. Four native species were introduced: two helophytes (Carex nigra, Eriophorum angustifolium) and two hydrophytes (Chara globularis, Chara vulgaris), and monitored over two years. Hydrophytes initially grew well but did not develop the next season, likely due to early desiccation and absence of oospores. Following new trials with fertile material the second season, hydrophytes partially reappeared in both original and replanted coir rolls at the end of the third season. Helophytes exhibited high survival (> 97%), progressive clonal expansion, and flowering from the second year. Thirty macrophyte species were recorded cumulatively in adjacent riprap and nearby water bodies, highlighting the potential for gradual recolonization. Consistently, five additional species colonized the coir rolls spontaneously, signalling the onset of secondary succession along revegetated banks. The results demonstrate that coir rolls can durably establish helophytes in snowmaking reservoirs without impeding their operation, providing a functional littoral ecotone, but that hydrophytes may need adapted technique and water elevation management.

La définition d’états de référence joue un rôle clé en restauration écologique, en servant de point de repère pour évaluer la dynamique de restauration des écosystèmes. Toutefois, le choix de cette référence n'est jamais totalement objectif et dépend de nombreux facteurs contextuels, tels que l’histoire et la géographie du site, son intégrité écologique initiale, ou les intérêts des parties prenantes. Pour éclairer les choix effectués lors de la définition des états de référence en restauration écologique, nous avons analysé 32 projets de restauration mis en œuvre et suivis dans une diversité d’écosystèmes terrestres et aquatiques entre 1999 et 2023 par des chercheurs du réseau « Restauration écologique INRAE » (REI, https://restauration-ecologique.hub.inrae.fr). Nos résultats mettent en évidence des tendances commune dans les critères mobilisés pour la sélection des références, tout en révélant des degrés d’accord variable entre projets, avec des différences notables entre les projets aquatiques et terrestres en termes d'implication des parties prenantes, des métriques choisies et des mesures d'évaluation. Cette étude constitue une première étape avant une enquête au sein de la communauté scientifique internationale. L’objectif est ainsi d’explorer plus en profondeur les défis liés à la définition des états de référence, en particulier dans le contexte d’accélération des changements globaux (notamment climatiques) et celui de la mise en œuvre du nouveau règlement sur la restauration de la nature dans les États membres de l’Union européenne.

Despite the wide distribution of Alnus glutinosa (L.) Gaertn. (Black alder) across riparian corridors in Europe and Western and Central Asia, it remains unclear whether root biomechanical properties and root reinforcement are conserved among environmentally distinct populations. The present study addresses this gap by conducting a comparative assessment of root systems from two contrasting riparian environments: a temperate Alpine-Mediterranean site (FR-G) and a humid temperate Hyrcanian site (IR-S). Field investigations were performed using the profile trenching method to quantify root spatial distribution, tensile force, tensile strength, Root Area Ratio (RAR), and Root Biomass Density (RBD). Root-induced cohesion (Cr) was estimated using the Wu-Waldron model, and riverbank stability was evaluated through limit equilibrium methods (LEM) implemented in Slide software under silty sand (SM) conditions, both in the presence and absence of root reinforcement. The results demonstrated a pronounced inverse logarithmic relationship between root diameter and tensile strength in both sites (adjusted R-2 > 0.87). Analysis of covariance (ANCOVA), incorporating soil depth as a covariate, identified depth as the principal factor controlling RAR, RBD, and Cr (p < 0.001), whereas environmental origin exerted no statistically significant effect. Root reinforcement markedly enhanced soil cohesion, with maximum Cr values of 18.2 kPa (FR-G) and 15.8 kPa (IR-S) recorded at 10 cm depth. Riverbank stability analysis indicated that the inclusion of roots increased the factor of safety (FOS) by an average of 18%, deepened the critical slip surface, and shifted potential failure mechanisms from shallow translational slides toward deeper and more extensive failure surfaces. Collectively, these results demonstrate that A. glutinosa provides consistent and effective root reinforcement across contrasting temperate environments. By enhancing soil cohesion and increasing riverbank stability, the species represents a reliable nature-based solution for the stabilization of cohesionless riparian soils, with strong potential for broader application in soil bioengineering design.

Knotweeds (Reynoutria taxa) rank among the most problematic invasive plants worldwide. Although interspecific hybridisation and diverse hybrid combinations in the wild are well documented, the evolutionary potential arising from hybridisation and polyploidisation remains less clear. Moreover, the suspected genetic variability of R. japonica var. japonica in the introduced range has never been conclusively demonstrated.,We sampled populations across river catchments in France, Germany, the Czech Republic, Croatia, and Slovenia. Morphological, cytological, and genetic population structure was assessed using flow cytometry and microsatellite (SSR) markers scored as presence/absence data. Seeds were collected from female and hermaphrodite maternal plants, germinated under controlled conditions, and seedlings were assessed for genome size and vitality.,Genetic variability within R. japonica var. japonica was, for the first time, conclusively demonstrated in the Sava River population (Croatia), supported by cytological, morphological, and molecular evidence. Hybrid populations exhibited significant cytological and genotypic variation across all localities, consistent with ongoing generative reproduction. Seeds from octoploid maternal plants germinated at the highest rates (~75%), and the most vigorous seedlings originated from octoploid mothers of both R. japonica and R. ×bohemica, with genome sizes corresponding to the octoploid cytotype. Hexaploid R. ×bohemica clones showed lower germination rates and vitality. Reynoutria sachalinensis was absent from all sites and no F₁ hybrids were detected.,Together, these findings indicate that generative reproduction is playing an increasingly important role in shaping the genetic and cytological diversity of introduced knotweed populations, with consequences for both their evolutionary adaptability and the effectiveness of management interventions.

The spatial and temporal distribution of soil reinforcement is closely linked to tree root arrangements in riparian soils which remains demanding to measure. Estimations of root-related soil reinforcement are used to predict bank stability, for example following the implementation of riverbank stabilization structures. In riparian environments, a frequently encountered pioneer species is willow (Salix L.). Previous studies looking at willows root reinforcement in riverbanks mainly focused on young cuttings or on vegetation mixes. Here, we analyzed more than 2000 willow root measurements taken from 11 long-established sectors at two riverbank sites with low cohesive characteristics. The statistics of (horizontal and vertical) root distribution are presented alongside information on the respective contributions of the different root diameters to stabilizing effects and discussion of what type of reinforcement they can provide in this setting is discussed. Field data is then compared to the 1D Tron-model-based estimation of vertical root biomass, linking root distribution to groundwater level. Finally, we estimate the modification on critical shear stress of riverbanks induced by willows roots for the sites examined. The proposed three-step method yields promising results for the two field sites. The outcomes are highly relevant for practical applications, providing a quantification of the spatial distribution of willow roots in riparian soils and an assessment of their potential contribution to bank reinforcement, thereby supporting future operational use.

Soil and water bioengineering (SWBE), the most frequently mentioned Nature Based Solution for substrate mass movement protection and erosion control, represents a subset of civil engineering solutions. SWBE approaches have been the subject of considerable literature, particularly in temperate environments, but have received less attention in the tropics, despite frequent occurrences of soil erosion and substrate mass movement with severe consequences. A review of SWBE experiments and a list of suitable species were still lacking. We conducted a literature review on more than 800 references and selected 51 references that reported effective SWBE projects. From each reference, we extracted 14 variables related to the context, technical aims, structures implemented and project monitoring. We also completed a list of the tropical species used or recommended for SWBE, along with their taxonomy, growth form, means of propagation and native distribution range. Our results show heterogeneous efforts, with Africa and Oceania neglected. In America and Asia, a diversity of SWBE techniques (n = 28) were successfully implemented. However, monitoring was only conducted over the short term and without standardized evaluation methods. Of the 465 bioengineering species mentioned in the tropics worldwide, only 25% have been tested in situ, mostly outside their native range and with a limited number of species in each study. SWBE has promise in the tropics, but there is still a lack of knowledge concerning suitable tropical species and their development and biotechnical performance. Investigations including well-defined, long-term, standardized monitoring methods are needed to assist practitioners and to facilitate SWBE transferability in the tropics.

Channel mobility is essential to maintaining a river's healthy biogeomorphic and ecological functions. Although, local erosion processes can sometimes require stabilization to protect infrastructure. Soil and Water Bioengineering (SWB) techniques use vegetation as living construction materials to provide effective erosion control while preserving riparian ecological functions. Designing these structures depends significantly on expert knowledge and technical documentation that shares best practices and experiences, and provides specific hydraulic stress resistance thresholds. There is currently only limited documentation regarding the use and mechanical resistance of SWB on mountain streambanks where the harsh climate and steep slopes put a strain on vegetation growth and recovering, which in turn makes it challenging to design effective SWB structures. This study aims to fill this gap by providing an exhaustive record of SWB works throughout the French Alps, with additional sites in Italy and Switzerland. Hydraulic parameters, vegetation dynamics, and failure mechanisms were assessed across 48 SWB works. Drawing on our expertise, we assessed the key factors governing the implementation and success of SWB works in mountain streambanks. Our survey revealed that the works could be classified along a "naturalness" gradient, with vegetation playing different structural roles. Riprap was commonly used at the bank toe and technical choices depended mostly on the cultural context of the watershed and the local knowledge of SWB rather than on the hydromorphological context or the assets to be protected. Ultimately, this study enhanced our understanding of the hydraulic stresses experienced by these structures and the most prevalent causes of failure.

Les retenues d’altitude constituent aujourd’hui une part significative du réseau de plans d’eau de montagne, mais leur création entraîne souvent la destruction de zones humides et d’habitats fonctionnels. Les inventaires biologiques qui y ont été réalisés témoignent de communautés considérablement appauvries et d’une quasi-absence de végétation aquatique, transformant certaines retenues en « pièges écologiques ». Pour tester des solutions permettant leur meilleure intégration environnementale, un projet de réhabilitation écologique comprenant notamment une expérimentale a été mené sur la retenue de l’Adret des Tuffes (Les Arcs 2000). Des fascines d’hélophytes et d’hydrophytes ont été implantées sur les berges et sur un radeau flottant. Les hélophytes se sont bien développées sur les berges et le radeau, tandis que les hydrophytes ont survécu sur le radeau mais très peu en berges, du fait des exondations printanières. Un suivi faunistique est actuellement réalisé pour évaluer la capacité d’accueil de ces aménagements, alors que la retenue présente initialement une faible abondance d’amphibiens et une diversité limitée d’invertébrés. Sur cette base, des recommandations sont proposées pour renforcer la qualité écologique des retenues existantes comme les caractéristiques du substrat et des pentes des berges, la végétalisation avec des espèces locales et l’adaptation des cycles de remplissage aux périodes de reproduction. Ces mesures visent à permettre de concilier au mieux usages humains et conservation de la biodiversité en montagne.

Soil and water bioengineering structures (SWBEs) implemented for riverbank stabilization are often designed based on field feedback and expert knowledge. These structures are weaker in the years just after implementation, before vegetation recovery, which limits their reliability and success rate. This study uses a 1:25-scale physical model to compare the failure processes of noncohesive riverbanks protected at their toe with riprap, early-stage fascines, or double fascines. The results highlight the key weak points that should be targeted to further improve SWBE design. In complement to qualitative observations, the topography is measured by photogrammetry before and after flooding with bankfull discharge. Pore pressure is measured in the channel bed and banks during the experiment. The results showed for banks with SWBE toe protection in meanders that (1) scour hole formation drives bank destabilization; (2) due to undermining (i.e., scouring), common SWBEs such as single-bundle fascines are insufficient to stop bank material falling into scour holes; (3) the bank toe can be stabilized by a combination of living structures (e.g., one bundle of fascines) and buried structures that play the role of filter, blocking bank material, and anchorage (here, a second bundle was used); (4) bank slope reduction reduces scour hole depth; and (5) in this scaled physical model without soil cohesion, bank erosion is driven by fluvial entrainment rather than by mass failure or water overpressure in the bank.

Alpine freshwater ecosystems are biodiversity hotspots providing key ecosystem services. These ecosystems face threats from climate change and anthropogenic activities. Snowmaking reservoirs have emerged across the globe as a response to snow rarefaction and increasing winter tourism, and despite efforts to assess their environmental impact, our understanding of their ecological quality after being built remains limited. In the present study, we evaluated representative snowmaking reservoirs in French Alpine counties (départements) and their potential to serve as aquatic ecosystems. A comprehensive approach was employed encompassing ski resort surveys and geographical analyses of 136 reservoirs, complemented by investigations into abiotic characteristics and biodiversity surveys in 28 sampled reservoirs. The findings indicated that the multiplication and proximity of these reservoirs to freshwater habitats make them components of the alpine aquatic landscape. Terrestrial vegetation, although sparse, was commonly present on the banks of these reservoirs, but they systematically lacked aquatic vegetation. Faunal diversity appeared to be limited, and consisted of both indigenous and non-native species. Comparisons of snowmaking reservoirs with mountain lakes revealed similarities in water quality, implying the potential for similar oligotrophy and biotic communities. However, differences in conductivity, alkalimetry and pH were observed, possibly linked to distinct differences in water sources or retention times. Snowmaking reservoirs displayed unique habitat features through their structure and functioning. Although these reservoirs are attractive in terms of their biodiversity, there are concerns regarding their capacity to support species due to observations of drowned mammals and stranded amphibians and dragonflies. Our observations reveal potential ecological traps in the design, exploitation and uses of snowmaking reservoirs. Recommendations are made to enhance existing structures and future designs by increasing ecological processes and better protecting biodiversity.

The use of Nature-based solutions for riverbank stabilization purposes in Western Europe is mainly based on willows implemented on engineered structures stabilizing riverbanks as they grow. Willows are ubiquitous and pioneer species capable of survival in submerged conditions when drowned a part of the year, therefore particularly well suited for soil and water bioengineering techniques. In the context of bend scour or of bed incision, bank toe bellow the line of brush growth is a weak point to control. This weaker zone presenting a low vegetation surface cover is in fact strongly subject to erosion leading to undermining and bank failure. This situation raised up the question: what is the effect on the soil stability of willows root reinforcement in this weak zone, knowing that their root system is allegdly able to develop in this part time drowned soil? In order to understand the stabilizing function of these species bellow the brush line, willows root system implemented on riverbanks from two different alpine watersheds in France have been surveyed in autumn 2023. The root development is studied in regard of the ground water level and soil texture. Nine soil profiles with willows root systems are described in the study and the respective root area ratios have been estimated manually. Soil profiles were dug up to the last visible root and never exceeded 80 cm, corresponding to the ground water level of the low flows that were running during the measurements. The study describe three different species root system aged from 2 to 20 years: Salix purpurea, S. daphnoides and S. eleagnos.

Les fascines d’hélophytes constituent une solution durable de génie végétal pour la stabilisation des berges en milieux aquatiques à faible énergie. Ces structures, composées de boudins en géotextile biodégradable remplis de matériaux granulaires et pré-plantés d’hélophytes, permettent de limiter l’érosion tout en favorisant la biodiversité. Leur mise en place assure une stabilisation immédiate, tandis que le développement racinaire des plantes renforce la cohésion du substrat à long terme. Adaptées aux eaux calmes (lacs, canaux, bras-morts), elles s’intègrent aux approches écologiques et économiques de gestion des berges. Cependant, leur efficacité dépend des conditions hydrodynamiques locales et de la sélection des espèces végétales. Encore sous-exploitées, ces structures méritent une attention accrue pour optimiser leur conception et élargir leur champ d’application.

QuestionsOne strategy to prevent invasive alien plant species from establishing during the restoration process is to early re-introduce native communities. But can seeding a native herbaceous species mixture of local seeds reduce the establishment of an invasive shrub such as Buddleja davidii? Specifically, we asked: (1) Does competition by native species reduce B. davidii performance? (2) Is this competitive effect on B. davidii more important under higher seed densities? (3) Can it be partly attributed to light competition? (4) How do priority effects moderate this competitive effect?LocationDisturbed embankment, Is & egrave;re, France.MethodsWe conducted experiments in controlled conditions, in mesocosms and in the field. We compared the performance of B. davidii when seeded alone or in competition with local seeds, at different densities, when shaded or not and when sown before or simultaneously with respect to native species.ResultsThe seeding of a local seed mixture decreased the height, biomass and early-stage survival of Buddleja davidii. Whatever the density, these results were consistent across all three experiments. Buddleja davidii's survival rate was reduced only under the experimental conditions of high shading. When native species were sown after B. davidii, their competitive effect was very low.ConclusionsBuddleja davidii appears to be sensitive to competition during the early stages of its invasion, especially when local seedlings benefit from a time advantage, regardless of their density. In restoration contexts, native species can prevent the invasion of B. davidii if sowing is carried out as soon as possible.

Streambank erosion control and management are experiencing a significant paradigm shift, particularly in mountainous regions. There is an increasing demand for Nature-based Solutions such as soil and water bioengineering techniques (SWBE) with living plant material to protect both human assets and biodiversity from streambank erosion. The success of these techniques is highly dependent on vegetation growth and requires solid knowledge of the local species used. However, our knowledge of appropriate subalpine species is still limited, thus hindering the advancement of effective SWBE in these environments. To address this gap, we established an ex-situ experiment to study the biotechnical traits of subalpine species that contribute to streambank protection. Four species were cultivated in a growth chamber for four months: Salix caesia Vill., Salix foetida Schleich. ex DC. and Salix hastata Vill., restricted to the subalpine belt, and Salix purpurea L., a ubiquitous species. We then assessed both aerial and root traits (number, length and biomass) to evaluate the species' potential for use in erosion control. The survival rate was excellent - up to 96%. S. hastata had high belowground biomass, promising for substrate stabilization, while S. purpurea produced numerous long shoots appropriate for surface protection. The two other willow species provided intermediate benefits, but their presence could promote biodiversity in SWBE structures. Our study reveals promising potential for the use of these species in high-elevation SWBE. Their morphological differences suggest that the four species should be used in accordance with specific streambank contexts.

Soil and Water Bioengineering techniques are a sustainable alternative to civil engineering to prevent erosion processes that threaten streambank stability. These techniques are still poorly developed and documented in subalpine streams, where climatic and hydrological conditions are particularly challenging. It is well known that the success and integration of a SWBE technique is best achieved when it is possible to use indigenous plants and plant material. At the subalpine belt, shrub and tree willows are among the dominant woody species on streambanks. Even if a few past studies claimed that they could play a full role in stabilising the banks of high-elevation streams, their biotechnical characteristics are nearly unknown. The unique information available comes from empirical and not detailed results showing a low resprouting rate of cuttings. Still, no data or information on these capacities are known in the subalpine environment. We conducted an in situ experimental study to assess the cutting capacity of willow species at high elevations to improve SWBE on these streambanks.Three species of subalpine shrub willow were chosen: S.caesia, S.foetida and S.hastata. These willows have no protected status in the French Alps, making them ideal for soil and water bioengineering. S.purpurea, known for its high resprouting ability in foothill streambanks, was used as a control species. The cuttings were placed in culture chambers for 4 months under controlled conditions of light, humidity, and temperature. We tested the effect of a growth hormone (indole-3-butyric acid), with the assumption that it would stimulate willow growth. 25 cuttings from each species were treated with the hormone while another 25 were not treated. At the end, we measured root diameter, primary root number, root biomass, cumulated stem length, stem number and, stem and leaves biomass. The recovery rate was high for all four species (>95%). No significant differences were found between the hormonal treatments. For each trait measured, there were significant differences for at least one of the species, reflecting significant differences in root and aerial morphology between species. S.hastata was distinguished by its very high biomass and S. purpurea by its very long structure. The results revealed significant differences between these species, in terms of morphology, resource allocation and therefore properties for soil and water bioengineering structures. All of the four species appeared to be suitable in SWBE structures. These findings have important implications for the effective installation of cuttings in SWBE structures in subalpine environments.

La ripisylve désigne l’ensemble des peuplements forestiers et boisements linéaires situés aux abords des cours d'eau, à l’interface entre les milieux aquatique et terrestre. Ces dernières décennies, un nombre croissant d’études scientifiques ont mis en lumière les intérêts écologiques, sociétaux et économiques de la préservation et de la restauration des ripisylves. Dans la première partie de cet article, nous synthétisons les bénéfices associés aux ripisylves. Nous présentons, dans une seconde partie, les éléments soutenant la préservation et la restauration des ripisylves comme des stratégies d’atténuation du changement climatique et d'adaptation à ses effets sur les rivières, la biodiversité et les humains. Ces caractéristiques font de la restauration de la végétation des berges des cours d’eau une mesure de gestion à développer dans les années à venir, dans un cadre réfléchi et adapté aux contraintes locales.

Le bâchage, méthode mécanique consistant à opposer une barrière physique à la croissance des plantes en plaquant un matériau sur le sol, est régulièrement cité comme une méthode de lutte contre les renouées asiatiques, mais reste très peu documentée. Nous avons réalisé une revue de littérature et une collecte de retours d’expériences afin d’améliorer les connaissances sur la méthode et tenter d'identifier les facteurs clés de succès. Le bâchage semble de plus en plus fréquemment utilisé en France comme à l'étranger, mais les pratiques et les itinéraires techniques très variés observés amènent à des résultats contrastés. Cependant, en analysant les données collectées, nous montrons que le bâchage peut être efficace sous certaines conditions et même mener à une éradication complète. Pour cela, la prise en compte des caractéristiques biologiques des renouées est indispensable. Ainsi, nous recommandons (si l’objectif visé est l’éradication) de bâcher l’intégralité du massif avec une distance de pose de quatre mètres au-delà des limites du massif (compte tenu des capacités d’expansion des rhizomes souterrains) pour une durée minimale de six ans, avec l’utilisation d’un matériau résistant d’une durée de vie équivalente. Un suivi régulier pendant toute la durée de l’opération est nécessaire afin d’assurer l’étanchéité du dispositif.