Guillaume Fried

Guillaume Fried
Agence Nationale de Sécurité Sanitaire de l'Alimentation, de l'Environnement et du Travail | ANSES · ANSES Plant Health Laboratory

PhD HDR

About

179
Publications
53,199
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Introduction
My research work is aimed at assessing the impact of human activities on the environment and more specifically on vegetation. I study two main models: i) the effects of alien plants introduction and their impact on wild vegetation or crops, and ii) the impact of agricultural practices on the flora of cultivated fields and its immediate environment, the field borders. I use and test hypotheses of community ecology with functional approaches, landscape ecology, macroecology and biogeography.
Additional affiliations
September 2008 - present
L'institut Agro | Montpellier SupAgro
Position
  • Professor
Description
  • Course on Invasive Plants, weed seedling's identification, weed sampling methods
March 2008 - present
Agence Nationale de Sécurité Sanitaire de l'Alimentation, de l'Environnement et du Travail
Position
  • Project Manager
October 2004 - February 2008
Education

Publications

Publications (179)
Article
Full-text available
It is well known that alien plant invasion modifies the composition and diversity of resident plant communities, yet our ability to predict patterns of vegetation responses to invasion is hampered by a poor understanding of which functional traits make some resident plants more or less vulnerable to invader impacts. For example, resident species ma...
Article
Biological invasions are permanent threat to biodiversity hotspots such as the Mediterranean Basin. However, research effort on alien species has been uneven so far and most countries of North Africa such as Algeria has not yet been the subject of a comprehensive inventory of introduced, naturalized and invasive species. Thus, the present study was...
Article
Full-text available
Aim: The abundance-frequency relationship (AFR) is among the most-investigated pattern in biogeography, yet the relative contributions of niche-based processes related to ecological strategies, and of neutral processes related to spatial colonization-extinction dynamics, remains uncertain. Here, we tested the influences of ecological specialization...
Article
Full-text available
Biodiversity has undergone a major decline throughout recent decades, particularly in farmland. Agricultural practices are recognised to be an important pressure on farmland biodiversity, and pesticides are suspected to be one of the main causes of this decline in biodiversity. As part of the national plan for reduction of pesticides use (Ecophyto)...
Article
Full-text available
Vineyards are an appropriate model for testing the filtering effect of management practices on weed communities, as a wide range of practices (tillage, herbicides and mowing) is implemented. The aim of this study is to highlight which trait values are selected by each practice in different environmental conditions, with special references to Grime'...
Article
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Background and Aims Decomposition is a major ecosystem process which improves soil quality. Despite that, only a few studies have analysed decomposition in an agricultural context, while most agrosystems (e.g. vineyards) are facing decreasing soil quality. The objective of this study is to understand the impacts of both pedoclimate and weed managem...
Article
Full-text available
La graminée Panicum hillmanii Chase originaire du nord de l'Amérique et naturalisée en France a été observée pour la première fois dans le Sud-Est, en Provence, en 1992, puis dans l'ouest du pays plus récemment, au cours des années 2000 et 2010. Elle vient d'être découverte en Languedoc, plus précisément dans le Gard et l'Hérault, dans quatre local...
Article
Full-text available
Winegrowers have diversified their weed management practices over the last two decades changing the structure and the composition of weed communities. Complementary to taxonomic studies, trait-based approaches are promising ways for a better understanding of weed community responses to environmental and agronomic filters. In the present study, the...
Chapter
Full-text available
La flore des parcelles viticoles est diverse et occupe une place spatiale et temporelle importante dans les vignobles ; elle varie selon les pratiques d'entretien du sol et le pédoclimat. La gestion de cette flore est déterminée selon des objectifs de rendement et de qualité, et également des enjeux écologiques (herbicides, énergie fossile, et tran...
Article
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Collectif, 2022-Cent observations botaniques remarquables en région Occitanie depuis l'an 2000 1 Title One hundred remarkable botanical observations in the Occitanie region since the year 2000 Résumé À l'occasion de l'édition du numéro 100 de Carnets botaniques, cet article collectif présente cent plantes observées en région Occitanie depuis l'an 2...
Article
Full-text available
Depuis 2012, un réseau de 500 parcelles agricoles est suivi pour mesurer l'impact des pratiques agricoles sur la biodiversité à travers quatre taxons indicateurs, dont la flore des bords de champs. Dans l'ex-région Languedoc-Roussillon, 21 parcelles sont suivies et on fait l'objet en 2017 de deux relevés : l'un par les observateurs habituels du rés...
Article
Full-text available
Deux nouvelles espèces de wolffies en France métropolitaine : Wolffia columbiana H. Karst. et W. globosa (Roxb.) Hartog & Plas (Araceae) Résumé. Trois espèces de Wolffia sont dorénavant connues en France métropolitaine : l'espèce indigène W. arrhiza (L.) Horkel ex Wimm. et deux espèces exotiques nouvellement détectées en 2020 (W. columbiana H. Kars...
Article
Cropping system (CS) diversification appears as a promising solution to increase CS sustainability. However, weed community response to different options of CS diversification remains poorly documented. Moreover, these effects are expected to be more pronounced in experimental than commercial farms because experimental farms explore more diverse co...
Article
Some troublesome weeds such as Ambrosia artemisiifolia have led farmers to adopt herbicide-tolerant varieties (HTVs) in cultivated sunflower fields. Agricultural practices associated with the use of HTVs have raised concerns among public authorities, prompting the recommendation to monitor the potential effects of HTVs on biodiversity. In this cont...
Article
Full-text available
Two scientific disciplines, vegetation science and weed science, study arable weed vegetation, which has seen a strong diversity decrease in Europe over the last decades. We compared two collections of plot‐based vegetation records originating from these two disciplines. The aim was to check the suitability of the collections for joint analysis and...
Preprint
Full-text available
Winegrowers have diversified their weed management practices over the last two decades changing the structure and the composition of weed communities. Complementary to taxonomic studies, trait-based approaches are promising ways for a better understanding of weed communities responses to environmental and agronomic filters. In the present study, th...
Article
Full-text available
Abstract Optimizing the effect of management practices on weed population dynamics is challenging due to the difficulties in inferring demographic parameters in seed banks and their response to disturbance. Here, we used a long‐term plant survey between 2006 and 2012 in 46 French vineyards and quantified the effects of management practices (tillage...
Article
Aim Humans influence species distributions by modifying the environment and by dispersing species beyond their natural ranges. Populations of species that have established in disjunct regions of the world may exhibit trait differentiation from native populations due to founder effects and adaptations to selection pressures in each distributional re...
Article
Full-text available
In the south of France, around the Salagou lake (Hérault), the observation of three populations of Wolffia globosa (Roxb.) Hartog & Plas (Araceae), a small duckweed of paleotropical origin, is the first record of this species in France. This discovery brings the number of Wolffia present in France to three. Here we summarise the available data conc...
Article
Questions: Studies in functional biogeography have mostly focused on unmanaged ecosystems, and neglected testing how management intensity affects community-level plant trait response to bioclimatic gradients. We hypothesize that trait-climate relationships for arable weeds spontaneously establishing in croplands, subject to intensive management, sh...
Article
Ambrosia trifida L. (giant ragweed, Asteraceae) is native to the North American continent and was introduced into Europe and Asia at the end of the 19th century. In its native range, this tall annual species is common in riparian and ruderal habitats and is also a major weed in annual cropping systems. For nearly a century, A. trifida has also been...
Article
Conservation agriculture has been identified as one of the farming systems likely to deliver sustainable agriculture but its effects over time on the diversity and composition of weed communities are poorly documented. Using a network of 100 winter wheat fields selected to encompass a gradient of years in conservation agriculture from 1 to 20 years...
Article
Full-text available
“Arable Weeds and Management in Europe” is a collection of weed vegetation records from arable fields in Europe, initiated within the Working Group Weeds and Biodiversity of the European Weed Research Society (EWRS). Vegetation-plot data from this scientific community was not previously contributed to databases. We aim to prove the usefulness of co...
Article
Full-text available
Establishing laws of plant and ecosystems functioning has been an enduring objective of functional and evolutionary ecology. However, most theories neglect the role of human activities in creating novel ecosystems characterized by species assemblages and environmental factors not observed in natural systems. We argue that agricultural weeds, as an...
Article
Full-text available
Prioritising the management of invasive alien species (IAS) is of global importance and within Europe integral to the EU IAS regulation. To prioritise management effectively the risks posed by IAS need to be assessed, but so too does the feasibility of their management. While the risk of IAS to the EU has been assessed, the feasibility of managemen...
Data
A species-rich weed community in South France, photographed in May 2018. It shows some threatened weeds of Mediterrean origin, but also the high temporal variability of these communities: in 2018, the rainy winter and spring allowed very high density of weeds in cultivated fields and fallows of the area, while most of the time the weed populations...
Article
Full-text available
Trifolium sylvaticum Gérard ex Loisel., a widely distributed Eurymediterranean species, is a rare taxon in France. It has just been discovered in the centre-Hérault, in the commune of Saint-Jean-de-Fos, in a rather atypical environment for the region, with other rare species such as Trifolium bocconei Savi. This observation completes the range of t...
Article
Full-text available
The definition of “arable weeds” remains contentious. Although much attention has been devoted to specialized, segetal weeds, many taxa found in arable fields also commonly occur in other habitats. The extent to which adjacent habitats are favourable to the weed flora and act as potential sources of colonisers in arable fields remains unclear. In a...
Article
Full-text available
A natural hybrid between Linaria arvensis and Linaria simplex was found at Saint-Jean-de-Fos (Hérault) region of France in decalcified fallow land in a post-cultivation situation (abandoned vineyard). This is the second observation of the hybrid after its description in its unique known location in Spain. Its description is given as well as the cha...
Article
Full-text available
The trait‐based approach can address questions in order to understand how the functioning of organisms scales up to that of ecosystems and controls some of the services they deliver to humans, including in agriculture. However, the importance of interspecific vs the intraspecific trait variability (ITV) for classifying species according to their tr...
Article
Full-text available
An amendment to this paper has been published and can be accessed via a link at the top of the paper.
Preprint
Full-text available
Optimizing the effect of management practices on weed population dynamics is challenging due to the difficulties in inferring demographic parameters in seed banks and their response to disturbance. Here, we used a long-term plant survey between 2006 and 2012 in 46 French vineyards and quantified the effects of management practices (tillage, mowing...
Article
Full-text available
The use of functional information in the form of species traits plays an important role in explaining biodiversity patterns and responses to environmental changes. Although relationships between species composition, their traits, and the environment have been extensively studied on a case-by-case basis, results are variable, and it remains unclear...
Chapter
North-Western Europe is probably the region where the cultivated agro-ecosystem has been modified most rapidly and profoundly with the intensification of agricultural practices during the twentieth century. While the richness and abundance of arable weed species has declined overall, some species historically dependent on cereals (so called ‘segeta...
Article
Full-text available
Invasion ecology has a long tradition of searching for traits distinguishing alien invasive and non-invasive plants. Surprisingly, this approach has been so far poorly used to understand why some arable weeds are abundant and widespread while others are rare and narrowly distributed. In the present study, we focus on the characteristics of successf...
Preprint
Full-text available
Invasion ecology has a long tradition of searching for traits distinguishing alien invasive and non-invasive plants. Surprisingly, this approach has been so far poorly used to understand why some arable weeds are abundant and widespread while others are rare and narrowly distributed. In the present study, we focused on the characteristics of succes...
Conference Paper
Full-text available
In order to have a factual view of the presence of Ambrosia trifida in Occitanie, the SRAL launched in 2018 a study with a double challenge: to better know and update the geographical distribution of the plant and to identify the management levers mobilized by farmers to date. This responded to an ANSES opinion (2017), considering that the sanitary...
Article
Long-term national European weed surveys, large scale classical phytosociological programs and camera-based documentation systems lead to results which can be documented in form of maps. Comparisons of these visual representations of relative weed positions can be used for the prediction of changing weed spectra and of plant biodiversity changes. S...
Article
Full-text available
The family Cactaceae Juss. contains some of the most widespread and damaging invasive alien plant species in the world, with Australia (39 species), South Africa (35) and Spain (24) being the main hotspots of invasion. The Global Cactus Working Group (IOBC GCWG) was launched in 2015 to improve international collaboration and identify key actions th...
Article
Alley cropping agroforestry is a land use practice in which arable crops are grown between tree rows. In such agroforestry systems, non-crop herbaceous vegetation develops on the tree rows, resulting in understory vegetation strips (UVS). UVS are perceived both as reservoirs for weeds and opportunities for biodiversity conservation. The purpose of...
Article
Full-text available
1. Combining several crop species and associated agricultural practices in a crop sequence has the potential to control weed abundance while promoting weed diversity in arable fields. However, how the variability of environmental conditions that arise from crop sequences affects weed diversity and abundance remains poorly understood, most previous...
Article
Full-text available
Standardized tools are needed to identify and prioritize the most harmful non-native species (NNS). A plethora of assessment protocols have been developed to evaluate the current and potential impacts of non-native species, but consistency among them has received limited attention. To estimate the consistency across impact assessment protocols, 89...
Thesis
Full-text available
Une question fondamentale en écologie est de comprendre pourquoi certaines espèces sont abondantes et largement distribuées quand d’autres sont rares et ont une distribution limitée. Nos travaux de recherche ont décliné cette question à travers deux modèles d’études : i) comment expliquer le succès versus l’échec de plantes non-indigènes introduite...
Article
Full-text available
Pour évaluer les effets non intentionnels des pratiques agricoles sur la biodiversité, un réseau de 500parcelles (réseau Biovigilance 500 ENI) a été mis en place en France métropolitaine par les pouvoirspublics. Quatre taxons sont suivis depuis 2012 : les vers de terre, la flore des bordures de champs, lescoléoptères et les oiseaux. Nous présentons...
Technical Report
Full-text available
La berce du Caucase, Heracleum mantegazzianum Sommier & Levier (Apiaceae), est une plante pérenne monocarpique. Cette plante exotique envahissante est maintenant interdite du fait de son inscription dans la liste du règlement n° 1143/2014 de l’UE. Elle est présente sur le territoire français, à des densités fortement variables en fonction des régio...
Poster
Full-text available
The pollen of the well known common ragweed (Ambrosia artemisiifolia L.) causes allergic reactions in many people. But what about others ragweed species existing in Europe? The French Agency for Food, Environmental and Occupational Health & Safety (ANSES) has conducted risk analyses for two ragweed species (Ambrosia trifida L. (1) and Ambrosia psil...
Article
To assess the unwanted side effects of farming practices on non-target plants, we used a nationwide survey of the vegetation of arable field margin strips. The vegetation was surveyed during two years (2013, 2014) in 430 field margins distributed over all agricultural regions of France. We used two complementary multivariate, trait-based approaches...
Article
Full-text available
To better manage invasive populations, it is vital to understand the environmental drivers underlying spatial variation in demographic performance of invasive individuals and populations. The invasive common ragweed, Ambrosia artemisiifolia, has severe adverse effects on agriculture and human health, due to its vast production of seeds and allergen...
Article
Full-text available
Dispersal, abiotic and biotic constraints are all involved in explaining the success of invasive plants but how these factors influence the different life stages of an invader remains poorly known. Focusing on highly invaded riparian habitats we asked: (1) how do propagule pressure, resource availability and resident vegetation influence the succes...
Article
A la demande des Ministères chargés de la santé, de l'environnement et de l'Agriculture, l'ANSES a réalisé des ARP de l'ambroisie trifide (Ambrosia trifida) et l'ambroisie à épis lisses (Ambrosia psilostachya). Résultat : Malgré la proximité botanique de ces espèces, le groupe d'expert a proposé deux conclusions différentes. Si l'ambroisie à épis l...
Data
The database includes a list of 1577 weed plant taxa found in cultivated fields of France and UK, along with basic ecological and biogeographical information. The database is a CSV file in which the columns are separated with comma, and the decimal sign is ".". It can be imported in R with the command "tax.discoweed <- read.csv("tax.discoweed_18Dec...
Article
Full-text available
Focus Ibicella lutea (Lindl.) Van Eselt. 53 Focus Ibicella lutea (Lindl.) Van Eselt. Focus sur une espèce : Ibicella lutea (Lindl.) Van Eselt. Nouvelle observation d'une curieuse plante dans la Haute Garonne