Sven Bacher
titular professor
sven.bacher@unifr.ch
+41 26 300 8822
https://orcid.org/0000-0001-5147-7165
Prof.tit., Dr., group leader, applied ecology
Prof.tit., PhD, Group Leader, Applied Ecology
Senior Researcher
Department of Biology
Ch. Du Musée 15
1700 Fribourg
Senior Researcher
Department of Biology
Ch. Du Musée 15
1700 Fribourg
Biography
GoogleScholar
Employment history
2007- present University of Fribourg, research group leader
2007 University of Potsdam (D), full professor, declined
1996-2007 University of Bern, Group leader
1993-1996 ETH Zurich (PhD)
1991-1993 CABI Bioscience Centre Délémont
Prizes, awards, fellowships
2017-21 Highly Cited Researcher (Clarivate Analytics, formerly Thompson/Reuters)
2016 CIB Fellowship, Centre of Invasion Biology, University of Stellenbosch (South Africa)
2015 Titular professorship, University of Fribourg
2003 Bernese Prize for Environmental Research (15000 CHF)
Research and publications
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All Publications
176 publications
Global Impacts Dataset of Invasive Alien Species (GIDIAS)
Scientific Data (2025) | Journal articleManagement Measures and Trends of Biological Invasions in Europe: A Survey‐Based Assessment of Local Managers
Global Change Biology (2025) | Journal articleGlobal Impacts Dataset of Invasive Alien Species (GIDIAS)
Lisanna Schmidt, Alberto Santini, Davide Santoro, Riccardo Scalera, Tinyiko Cavin Shivambu, Sima Sohrabi, Elena Tricarico, Alejandro Trillo, Pieter G. van't Hof, Lara Volery, Tsungai A. Zengeya, Aikaterini Christopoulou, Virginia G. Duboscq-Carra, Ioanna A. Angelidou, Pilar Castro-Díez, Paola Tatiana Flores Males, Phill Cassey, Sven Bacher, Ellen Ryan-Colton, Mario Coiro, Bella Galil, Martín A. Nuñez, Michael Ansong, Katharina Dehnen-Schmutz, Georgi Fayvush, Romina Daiana Fernandez, Ankila Hiremath, Makihiko Ikegami, Angeliki F. Martinou, Shana M. McDermott, Cristina Preda, Montserrat Vilà Planella, Olaf L. F. Weyl, Neelavara Ananthram Aravind, Katerina Athanasiou, Vidyadhar Atkore, Jacob N. Barney, Tim M. Blackburn, Eckehard G. Brockerhoff, Clinton Carbutt, Luca Carisio, Vanessa Céspedes, Diego F. Cisneros-Heredia, Meghan Cooling, Maarten de Groot, Jakovos Demetriou, James Dickey, Regan Early, Thomas Evans, Belinda Gallardo, Monica Gruber, Cang Hui, Jonathan Jeschke, Natalia Joelson, Mohd Asgar Khan, Sabrina Kumschick, Lori Lach, Katharina Lapin, Simone Lioy, Chunlong Liu, Zoe J. MacMullen, Manuela A. Mazzitelli, John Measey, Agata Mrugała, Camille Musseau, Helen F. Nahrung, Alessia Lucia Pepori, Luis R. Pertierra, Elizabeth F. Pienaar, Petr Pyšek, Gonzalo Rivas-Torres, Henry Rojas Martinez, JULISSA ROJAS-SANDOVAL, Ned Ryan-Schofield, Rocio Sanchez, (2025) | Data setGlobal Impacts Dataset of Invasive Alien Species (GIDIAS)
Sven Bacher, Ellen Ryan-Colton, Mario Coiro, Phill Cassey, Bella Galil, Martín A. Nuñez, Michael Ansong, Katharina Dehnen-Schmutz, Georgi Fayvush, Romina Daiana Fernandez, Ankila Hiremath, Makihiko Ikegami, Angeliki F. Martinou, Shana M. McDermott, Cristina Preda, Montserrat Vilà Planella, Olaf L. F. Weyl, Neelavara Ananthram Aravind, Katerina Athanasiou, Vidyadhar Atkore, Jacob N. Barney, Tim M. Blackburn, Eckehard G. Brockerhoff, Clinton Carbutt, Luca Carisio, Vanessa Céspedes, Diego F. Cisneros-Heredia, Meghan Cooling, Maarten de Groot, Jakovos Demetriou, James Dickey, Regan Early, Thomas Evans, Belinda Gallardo, Monica Gruber, Cang Hui, Jonathan Jeschke, Natalia Joelson, Mohd Asgar Khan, Sabrina Kumschick, Lori Lach, Katharina Lapin, Simone Lioy, Chunlong Liu, Zoe J. MacMullen, Manuela A. Mazzitelli, John Measey, Agata Mrugała, Camille Musseau, Helen F. Nahrung, Alessia Lucia Pepori, Luis R. Pertierra, Elizabeth F. Pienaar, Petr Pyšek, Gonzalo Rivas-Torres, Henry Rojas Martinez, JULISSA ROJAS-SANDOVAL, Ned Ryan-Schofield, Rocio Sanchez, Alberto Santini, Davide Santoro, Sima Sohrabi, Riccardo Scalera, Lisanna Schmidt, Tinyiko Cavin Shivambu, Elena Tricarico, Alejandro Trillo, Pieter G. van't Hof, Lara Volery, Tsungai A. Zengeya, Aikaterini Christopoulou, Virginia G. Duboscq-Carra, Ioanna A. Angelidou, Pilar Castro-Díez, Paola Tatiana Flores Males, (2025) | Data setIdentifying candidate host plants for trap cropping against Drosophila suzukii in vineyards
Journal of Pest Science (2024) | Journal articleHarms of introduced large herbivores outweigh their benefits, while both are greater on islands and for higher trophic levels
Zoé Bescond--Michel, Sven Bacher, Giovanni Vimercati, (2024) | PreprintBenefits do not balance costs of biological invasions
BioScience (2024) | Journal articleCurbing the major and growing threats from invasive alien species is urgent and achievable
Nature Ecology & Evolution (2024) | Journal articleRisks posed by invasive species to the provision of ecosystem services in Europe
Nature Communications (2024) | Journal articleEffects of pesticides on soil bacterial, fungal and protist communities, soil functions and grape quality in vineyards
Ecological Solutions and Evidence (2024) | Journal article -
Research projects
10002485 - Understanding positive and negative environmental and socio-economic impacts of alien species
Status: OngoingStart 01.01.2025 End 31.12.2028 Funding SNSF Open project sheet Alien species are a main driver of environmental change worldwide. About 40,000 species have established outside their native ranges, and their numbers are rapidly increasing. While many are innocuous, some devastate native biodiversity, ecosystem services, and human livelihoods. Alien species can also have positive environmental and socio-economic impacts, and it has been claimed, without empirical validation, that these impacts are underreported and underestimated in comparison with negative impacts. Notably, factors associated with variation in magnitude and frequency of both positive and negative impacts on native biodiversity and human well-being are poorly understood, mainly for the dearth of meaningful comparative efforts across taxonomic and environmental contexts. The project proposed here will overcome these difficulties by utilising the standardised impact frameworks S/EICAT(+) to (1) globally assess positive and negative environmental and socio-economic impacts of selected alien taxa, (2) quantify reporting bias in terms of impact direction and magnitude in different taxa, (3) identify determinants of impact direction, frequency and magnitude, and (4) test how well global impact assessments predict local impacts quantified through field studies and surveys in Galápagos, one of the most iconic World Heritage sites whose unique biodiversity is threatened by biological invasions. Global impact assessments will be performed by collecting data through systematic literature reviews and analysis of frequencies, magnitude and types of positive and negative impacts through the ICAT frameworks, i.e. the IUCN Environmental Impact Classification for Alien Taxa (EICAT), the Socio-Economic Impact Classification of Alien Taxa (SEICAT), the recently developed positive Environmental Impact Classification for Alien Taxa (EICAT+) and the positive Socio-Economic Impact Classification of Alien Taxa (SEICAT+). The latter framework will be developed and validated during the project. ICAT frameworks have been designed to facilitate impact comparisons between taxa and invasion contexts using a transparent and evidence-based, ordinal scoring. Assessed impact data will be analysed using a range of statistical methods such as generalised linear mixed effects models to identify determinants of environmental and socio-economic impacts and account for context-dependency. Local, standardised quantification and assessment of impacts of alien species at a World Heritage site, the Galápagos islands, will be conducted in field studies. Our results will influence policy and management of alien species globally (e.g. IUCN, CBD, GEO BON) and locally (Galápagos, Switzerland). Risk Assessment of Invasive Plants in Iran: Introducing A Practical Model For the Different Climate Zones
Status: CompletedStart 01.08.2021 End 31.10.2021 Funding SNSF Open project sheet In many countries, social and environmental costs of invasive alien plants (IAPs) have resulted in strict risk assessment and regulations against IAPs, while in Iran with a large area, long boarders with many countries, variable topography and climates, no official list of IAPs and thus, also no standard risk assessment models have yet been developed. Iran's bio-diversity ranks 18th in the world and there are 272 conservation areas for a total of 17 million hectares run as national parks, protected areas and natural wildlife refuges. In Switzerland, scientists are at the forefront in developing practical and useful models (EICAT and SEICAT) and experimental approaches (bio-geographic comparisons) to assess impacts of IAPs. In addition, a list of IAPs is well in place and regularly updated. In a joint effort between researchers from Iran and Switzerland, the current study specifically addresses the following objectives: 1) prepare a list of potential IAPs of Iran, 2) assess the invasion risk of the listed plants for the different climatic zones, 3) prepare a list of high risk (black list), medium risk (gray list) and low risk (white list) plant species for the different climatic zones, 4) prepare a map of the current species status and distributions, and 5) prepare a website similar as available for Switzerland that lists IAPs and their level of severity (https://www.infoflora.ch/en/neophytes/lists.html). The objective (5) can further lead to educating and training students, conservation practitioners and citizens and help enhancing general knowledge about the importance of invasive species. A literature survey using specific keywords from available data bases will provide a preliminary list of IAPs that will then be revised based on the data from herbarium, digital and hard copy resources of flora. We will assess the risk of the listed IAPs using various models of analysis. Model performance will be evaluated using validation tests, and may be further developed and adapted for the various climatic zones. The outcomes will not only provide a practical list and standard assessment method for IAPs of Iran, but also strengthen the international collaboration in the field of invasion science. InvasiBES
Status: CompletedStart 01.04.2019 End 31.12.2022 Funding SNSF Open project sheet Invasive Alien Species (IAS) are considered a direct driver of biodiversity loss and have pronounced negative impacts on supporting, provisioning, regulating and cultural services. Both the numbers and distributions of IAS are increasing in many parts of the world, to the extent that the biogeographic distinctiveness of different regions is becoming blurred. The costs of IAS, currently estimated at 12.5 to 20 billion € per year in Europe, and 120 billion $ per year in the US, are therefore set to increase. These costs mostly arise from economic loss in the agriculture, forestry, energy and health sectors, diminished delivery of ecosystem services, and cost of controlling and eradicating unwanted species. Past research on biological invasions has mainly focused on the ecological factors determining IAS success and distribution, treating ecosystem services only marginally, and focusing on particular species, habitats or ecosystem functions, such as nutrient and water cycling. Moreover, current knowledge on the impacts of IAS on ecosystem services is strongly biased towards terrestrial habitats and services that have marketable values (agriculture yields, forestry production, human health), whereas aquatic habitats and non-marketable services are largely ignored. By synthesizing knowledge across habitats (terrestrial, freshwater and marine) and scales (continental to local), InvasiBES aims to provide a comprehensive understanding of the multi-faceted impacts of IAS on biodiversity and ecosystem services. It has the following scientific objectives: - Develop three intervention scenarios of IAS management in Europe and the US (WP 1), - Adapt and test impact assessment protocols to consider the beneficial and detrimental effects of IAS on biodiversity and ecosystem services (WP 2), - Evaluate current and future impacts of IAS on biodiversity and ecosystem services in Europe (WP3), - Evaluate current and future impacts of IAS on biodiversity and ecosystem services in the US (WP4), - Evaluate the effects of IAS on biodiversity and ecosystem services using freshwater (WP5.1), terrestrial (WP5.2) and marine (WP 5.3) local case-studies. Dealing with uncertainty in alien species impact assessments
Status: CompletedStart 01.09.2018 End 31.12.2022 Funding SNSF Open project sheet The recently developed protocols EICAT and SEICAT allow classification of alien taxa according to the magnitude of their environmental and socio-economic impacts. EICAT has been adopted by the IUCN as a global standard for impacts of alien taxa. However, although they allow adding a confidence score to each assessment, the consideration of this uncertainty in the final classification is currently inadequate. This leads to inconsistencies in impact assessments among assessors. The proposed project addresses these inconsistencies and will provide solutions for the treatment of uncertainty. It has four aims: 1. Development of procedures and guidelines for the treatment of uncertainty in S/EICAT assessments 2. S/EICAT assessments of 2 model groups: global alien mammals and European alien beetles 3. Development of a publicly available database with S/EICAT assessments that can be used for future assessments of all alien taxa; this database will be available online and preferentially be hosted by a prominent international organization (e.g. IUCN) 4. Identification of factors explaining heterogeneity in impact magnitude in the two model groups The protocols that we will develop during this project for the treatment of uncertainty in S/EICAT assessments will make impact scores transparent and will reduce inconsistencies. This will improve our understanding of impacts of alien species and will allow the entire field of impact research to move forward. The database will be a cornerstone in the field of biological invasions and a reference for future studies that will increase our understanding of impacts in alien taxa. The expected results will enable us to carry out meaningful tests of various hypotheses on factors underlying heterogeneity in impact magnitudes. Importantly, the data and results of our analyses can be directly used by managers in decisions to prioritize alien species for management and may contribute to key global policy measures aimed at addressing the problems associated with biological invasions, such as the Convention on Biological Diversity's (CBD) Strategic Plan for Biodiversity 2020 and associated Aichi Target 9. Alien species: beyond a common exhibition
Status: CompletedStart 01.03.2018 End 30.11.2018 Funding SNSF Open project sheet Biological invasions are widely recognized as a key component of current global change. Currently, there is much debate among scientists and other stakeholders concerning the scale of the changes caused by alien species and the extent to which management intervention is warranted. On the one hand, alien species are globally considered one of the greatest threats to biodiversity through their interactions with other drivers of change. On the other hand, most of them are innocuous and some alien species even have benefits for society (as crops, ornamentals) or for nature, when they replace ecosystem functions of native species that have declined or disappeared due to habitat degradation. Meaningful management of invasions therefore depends on the discrimination between harmful, innocuous and useful alien species. Because of this management component, support from society is essential for this discipline, not only from policy makers but also from citizens. However, awareness and understanding of biological invasions is currently lacking in large parts of society. Many issues related to the missing support of invasion biology by society arise from inappropriate communication. The Natural History Museum Fribourg is conducting an exhibition on biological invasions in 2018. In the proposed Agora project, we use modern communication tools (smartphone applications, “smart mobs”) to engage the public in authentic dialogues with scientists and stakeholders about biological invasions. In this way, the Agora project complements and extends the museum exhibition and will also reach audiences that are usually difficult to reach by traditional museum exhibitions. This project asks for funding of two elements or activities: i) a scavenger hunt, guided by a smartphone application, in the surroundings of the museum including the Botanical Garden of Fribourg (BGF) and in the city of Fribourg; and ii) “smart mobs”, i.e. several coordinated public appearances of costumed characters, dressed as alien species, engaging the public in dialogs about biological invasions at different places within the agglomeration of Fribourg. The main objectives of the activities are • To make the players conscious that alien species are part of their everyday life and to provide the opportunity to visit places that are directly and visibly impacted by alien species. • To raise awareness of problematic alien species, their introduction pathways and the possible consequences of their deliberate or accidental release in a new habitat. • To encounter damaging as well as innocuous species and even species with positive effects for our society. • To highlight why studying alien species is central in conservation biology. The proposed Agora project will substantially contribute to a broad awareness and understanding of biological invasions in the general public by not only increasing knowledge about alien species but also by offering the opportunity to directly experience alien species and their consequences in nature. PromESSinG - Management concept for Central European vineyard ecosystems: Promoting ecosystem services in grapes
Status: CompletedStart 01.01.2015 End 30.11.2018 Funding SNSF Open project sheet New approaches are needed to secure food production while creating sustainable agricultural systems requiring as few external inputs as possible. The interaction between biodiversity and ecosystem services (ESS) is recognized to play a key role in this context although large gaps in knowledge exist. Cultivation of grapevine as a perennial crop, characterized as a highly input-intensive crop often grown for several decades on exposed locations with particular climatic conditions, has a high potential of providing ESS linked to biodiversity since viticulture does not aim at producing maximum yield but rather high quality products. Additionally, viticulture can provide high levels of biodiversity inside the cropped area which cannot be found in annual cropping systems. Thus, viticultural systems provide ideal conditions for analyzing ESS relevant for the grapevine grower such as soil fertility and stability, water retention, pest and weed control as well as grape quality in relation to soil biodiversity and functioning. The PromESSinG project responds to the need to unravel biodiversity driven processes associated with the main ESS in viticultural systems taking different spatial (field, landscape) scales into account. A particular focus will be on soil biodiversity, as interactions between the diverse soil biota as well as chemical and physical properties of the soil environment are fundamental for the provision of soil-based ecosystem services. The intended research will be conducted in temperate (non-Mediterranean) vineyard systems in France, Switzerland, Germany, Austria and Romania, thus covering a gradient from maritime to continental climates. In a common study with all countries involved and using a standardized sampling design we will analyze the links between diversity of soil relevant species groups (soil microflora including mycorrhiza, macrofauna, plants), soil function and respective supporting, regulating and provisioning ESS. Management effects on these interactions are analyzed on two different scales by combining a) the factor soil management including three vineyard ground management treatments of different disturbance intensities with b) the factor landscape management consisting of three landscape heterogeneity levels. In addition, individual studies based on already existing experimental sites in Germany, Switzerland and France focusing on nitrogen fertilization and farming type (integrated, organic, biodynamic) will further promote knowledge on biodiversity-ESS relationships in the vineyard. Thus, the major aim of PromESSinG is to identify management options for promoting biodiversity linked ESS in order to reduce external inputs in Central European vineyard ecosystems. The PromESSinG project will integrate the entire knowledge chain from providing novel and improved techniques for measuring ESS in viticulture, performing empirical research in a common study across countries, to fostering exchange and consultation with local and regional stakeholder in each country. The knowledge will be spread at all levels inside and outside the European Union to all major relevant stakeholders and interested parties to achieve improvements in the utilization of ecological services provided by soil and landscape management for the grapevine grower. BLISRo - Black List of Invasive Species in Romania
Status: CompletedNCCR: Plant survival in natural and agricultural ecosystems
Status: CompletedPRATIQUE: Enhancements of Pest Risk Analysis Techniques
Status: CompletedStart 01.03.2008 End 31.05.2011 Funding Europe Open project sheet PRATIQUE (Enhancements of Pest Risk Analysis Techniques) will carry out all the key work listed in the call and address the major challenges for pest risk analysis (PRA) in Europe. This will be achieved through three principal objectives: to assemble the datasets required to construct effective PRAs valid for the whole of the EU, to conduct multi-disciplinary research that enhances the techniques used in PRA and to ensure that the PRA decision support scheme meets its purpose, is efficient and user-friendly. Pest risk analysts, phytosanitary experts, invasive alien species specialists, ecologists, economists and risk modellers from 13 leading institutes in the EU, one from Australia and one from New Zealand will produce the first structured inventory of PRA datasets for the EU and undertake targeted research to improve existing procedures and develop new methods for (a) the assessment of economic, environmental and social impacts, (b) summarising risk in effective, harmonised ways that take account of uncertainty, (c) mapping endangered areas (d) pathway risk analysis and systems approaches and (e) guiding actions during emergencies caused by outbreaks of harmful pests. The results will be tested with a representative range of the major pests and invasive alien species affecting the cultivated and uncultivated habitats of the EU and will be independently validated by phytosanitary experts. The deliverables will be provided as protocols, decision support systems and computer programs with examples of best practice made available to pest risk analysts through modules and direct links to the PRA scheme. The PRA scheme will be web-enabled providing (i) new users with context-sensitive guidance, (ii) experts with a more efficient and user-friendly process and greatly enhanced access to key datasets and analytical tools, (iii) policy makers with an improved and robust scientific basis for managing risks and (iv) stakeholders with a transparent presentation of the risks. NCCR: Plant survival in natural and agricultural ecosystems
Status: CompletedStart 01.04.2001 End 31.03.2009 Funding Other Open project sheet The survival of plants is of fundamental importance to guarantee the biodiversity in natural areas and a sustainable agriculture. Since 2001, we have established an interdisciplinary network of scientists from several Swiss universities and federal institutes to study the interactions of plants with their environment. Our research topics are grouped in four main modules: natural and agro-ecosystems disease resistance and pest control energy and resources statistics and modelling