# Exploring the invasion history of an exotic pest based on genetic markers: the case of the Asian long-horned beetle (Anoplophora glabripennis).

Marion Javal, Alain Roques, Géraldine Roux

► To cite this version:

Marion Javal, Alain Roques, Géraldine Roux. Exploring the invasion history of an exotic pest based on genetic markers: the case of the Asian long-horned beetle (Anoplophora glabripennis). Neobiota 2016; 9. International Conference on Biological Invasions Biological Invasions: Interactions with Environmental Change, Sep 2016, Vianden, Luxembourg. Fondation faune-flore - Institut de recherche sur le patrimoine naturel et la diversité biologique, 2016, NEOBIOTA 2016. Biological Invasions: Interactions with Environmental Change. 9th International Conference on Biological Invasions. hal-01603593

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Book of Abstracts

Christian Ries & Yves Krippel (eds)

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NEOBIOTA 2016

Biological Invasions: Interactions
with Environmental Change

9th International Conference on Biological Invasions

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Photos: CC Wikimedia Commons

Vianden, Luxembourg

14 - 16 September 2016

www.neobiota2016.org

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Fonds National de la
Recherche Luxembourg

Supported by the Fonds National de la Recherche, Luxembourg
(Project Code 11253560)
Exploring the invasion history of an exotic pest based on genetic markers: the case of the Asian long-horned beetle (Anoplophora glabripennis).

Marion Javal, Alain Roques, Géraldine Roux

INRA, UR0633 Zoologie forestière, Orléans, France

Insects are one of the most numerous groups of alien organisms introduced in Europe and as a result of globalization, the number of human-mediated introductions keeps growing. Among all the continents, Asia is so far considered as the region from which most of the newly-arrived alien species originate.

The Asian long-horned beetle (ALB) Anoplophora glabripennis is one of the insect species which benefited from international freight from Asia to Europe. It has been first detected in North America in 1996, then in Europe in 2003. This highly polyphagous species is able to infest a wide range of deciduous trees, especially in urban areas where its management results in significant economic costs.

In a context of recent European outbreaks (France 2013, Switzerland and Finland 2015), and in order to anticipate and to manage further ALB introductions, it is particularly important to uncover population's invasion routes as well as their pathways of dispersal in the invaded areas.

This work aims at evaluating the genetic structure of invasive populations in order to assess if the European outbreaks resulted from multiple independent introduction events or from the dispersal of a primary introduced population. We used sequences of mitochondrial COI gene as a preliminary approach. Our dataset covered most of the European outbreaks, some populations in North America and some in the native Asian range.

So far, the analysis of 36 populations from China and Korea revealed 23 haplotypes, with a very blurred geographic structure, probably resulting of an historic arrangement faded by potentially more recent population translocations, as hypothesized in previous studies. Only ten haplotypes were yet observed in Europe, three of them being shared with Asia and North America, five being private haplotypes and two being shared with Asia only. The genetic structure observed in Europe suggests a complex invasion scenario which likely includes several introduction events as well as dispersal within the invaded areas.

Keywords: invasive species, genetic structure, Asian Longhorned Beetle, Anoplophora, mitochondrial markers, insect
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NEOBIOTA 2016

Biological Invasions: Interactions with Environmental Change

9th International Conference on Biological Invasions

Vianden, Luxembourg

14-16 September 2016

**Book of Abstracts**

Christian Ries & Yves Krippel (eds)

Fondation faune-flore
Institut de recherche sur le patrimoine naturel et la diversité biologique

Supported by the Fonds national de la recherche, Luxembourg
(RESCOM/2016/11253560)
Impressum

Ries C. & Y. Krippel (2016) (eds). Biological Invasions: Interactions with Environmental Change. Book of abstracts. NEOBIOTA 2016 - 9th International Conference on Biological Invasions. Vianden, Luxembourg, 14-16 September 2016. Fondation faune-flore, Luxembourg. 256 pp. ISBN 978-99959-0-255-1.

This abstract book can be downloaded in PDF format from the neobiota.eu website.

Cover photos from https://commons.wikimedia.org (from left to right):

1. *Aedes albopictus* (Asian tiger mosquito), Maryland (US). Unknown date. Author: Susan Ellis, Bugwood.org.

2. *Fallopia japonica* (Japanese knotweed), Schwetzinger Hardt (Germany). 24 April 2015. Author: AnRo0002.

3. *Alopochen aegyptiaca* (Egyptian goose). Biyamiti Weir, Kruger NP (South Africa). 16 January 2015. Author: Bernard Dupont.

4. *Clathrus archeri* (Octopus stinkhorn). 25 October 2004. Author: Oilys.

5. *Trachemys scripta elegans* (Red-eared sliders). 17 May 2007. Author: Laszlo-photo.

6. *Neogobius kessleri* (Bighead goby), an invasive species from the Danube, here in the river Rhine at Arnhem (NL). 21 August 2009. Author: viridiflavus.

© Fondation faune-flore - Institut de recherche sur le patrimoine naturel et la diversité biologique. Luxembourg. www.faune-flore.lu

ISBN 978-99959-0-255-1
Table of contents

<table><tr><td>Partners & Sponsors</td><td>6</td></tr><tr><td>Introduction</td><td>7</td></tr><tr><td>Committees</td><td>8</td></tr><tr><td>Conference programme</td><td>9</td></tr></table>

<table><tr><td>Oral presentations</td><td>17</td></tr></table>

K1 Biological invasions and climate change 18

S1 Biological invasions and climate change 19

S2-3 Invader traits and characteristics of invaded communities 25

S3 Ecological impacts of biological invasions 35

K2 Biogeography and macroecology of invasions 40

S4-5 Biogeography and macroecology of invasions 41

S5 Invasive species and changes in landuse 48

K3 Non-native pests and pathogens 50

S6 Non-native pests and pathogens 51

S6 Socioeconomic impacts of biological invasions 53

S6 Restoration of invaded ecosystems 54

K4 Genetics and evolution of invasive species 56

S7-8 Genetics and evolution of invasive species 57

S8 Engaging the public with the topic on invasive species 63

K5 Eradication, management & control of invasive species 66

S9-10 Eradication, management & control of invasive species 67

S10 Biosecurity and risk assessment, including early detection and rapid response 73

<table><tr><td>Poster presentations</td><td>79</td></tr></table>

T01 Biological invasions and climate change 80

T02 Invader traits and characteristics of invaded communities 87

T03 Ecological impacts of biological invasions 116

T04 Biogeography and macroecology of invasions 139

T05 Invasive species and changes in landuse 156

T06 Non-native pests and pathogens 166

T07 Socioeconomic impacts of biological invasions 174

T08 Restoration of invaded ecosystems 176

T09 Genetics and evolution of invasive species 178

T10 Engaging the public with the topic on invasive species 197

T11 Eradication, management & control of invasive species 205

T12 Biosecurity and risk assessment, including early detection and rapid response 228

<table><tr><td>NEOBIOTA - European Group on Biological Invasions</td><td>244</td></tr></table>

<table><tr><td>NEOBIOTA conferences</td><td>245</td></tr></table>

<table><tr><td>NeoBiota Journal</td><td>246</td></tr></table>

<table><tr><td>Index of authors</td><td>248</td></tr></table>
# NEOBIOTA 2016 Partners and Sponsors

NEOBIOTA 2016 is organized by

* Fondation faune-flore - Institut de recherche sur le patrimoine naturel et la diversité biologique, Luxembourg

in co-operation with our international Partners

* NEOBIOTA - European Group on Biological Invasions

* European Weed Research Society (EWRS)

in co-operation with our Luxembourgian Partners & Sponsors

* Administration de la nature et des forêts (ANF)

* Fonds national de la recherche Luxembourg

* Ministère de l'économie – Direction générale du tourisme

* Ministère du développement durable et des infrastructures (MDDI) – Département de l'environnement

* Musée national d'histoire naturelle Luxembourg (MNHNL)

* Parc naturel de la Haute-Sûre

* Parc naturel de l'Our

* Société des naturalistes luxembourgeois a.s.b.l. (SNL)

* Station biologique SICONA

Further public and private partners

* Municipality of Vianden

* Municipality of Walferdange

* Vianden Castle (Les Amis du Château de Vianden a.s.b.l.)

* Tourist Office Vianden (Syndicat d'Initiative de Vianden a.s.b.l.)

Graphic and IT services

* Conference Management System (COMS), Korneuburg, Austria

* CUBE Werbung GmbH, Daleiden, Germany

* The Loupe IT-Services, Vianden

Cultural programme

* Ancien Cinéma a.s.b.l., Vianden

Catering

* Restaurant Veiner Stuff, Vianden

* De Schnékert, Windhof/Koerich
**Introduction**

"So globalised has everything become, that nothing is left in its accustomed place."

*"Nil, qua fuerat sede, reliquit pervius orbis."*<fnref n="1" />

Senecio, Medea II, V: 317.

Biological invasions are one of the components of global change, causing dramatic impacts on biodiversity and ecosystems. As in former conference editions, NEOBIOTA 2016 provides an international high-level forum to discuss how invaders respond to environmental changes and their feed-backs. Furthermore, the conference concentrates on the most recent studies on ecological and evolutionary characteristics of invasive alien species (IAS), invaded ecosystems and their management.

NEOBIOTA seeks a broad perspective, presenting oral and poster presentations on any taxonomic group, from microorganisms to vertebrates, any ecosystem type, and any region of the world. The conference constitutes an important opportunity to strengthen collaboration between the scientific community, conservation agencies, as well as policy and decision makers.

NEOBIOTA brings together a number of outstanding experts dealing with various aspects of biological invasions, including climate change, changes in land use, ecological and socioeconomic impacts, non-native pests and pathogens, genetics and evolution, invader traits and characteristics of invaded communities, biogeography and macroecology of invasions, ecosystem restoration, biosecurity and risk assessment, eradication, management and control of IAS and, lastly, ways to engage the public with the topic of IAS.

As for the abstracts submitted to NEOBIOTA 2016, we printed them as they were submitted by the authors, who assume responsibility for their own contents.

Two COST actions have meetings adjoining NEOBIOTA 2016 on September 11th-13th:
*Sustainable management of Ambrosia artemisiifolia in Europe* (SMARTER, FA1203, 2013-2017) and *European Information System for Alien Species* (Alien Challenge, TD1209, 2013-2017).

In the name of the Organizing Committee we hereby express our thanks to the Scientific Committee for the peer reviewing of the submissions, and to all partners and sponsors for their support. Their names can be found on dedicated pages inside this abstract book.

Luxembourg, August 2016
Christian Ries & Yves Krippel

www.neobiota2016.org
www.neobiota.eu

<footnote n="1">¹ Classical translation: "The world, now passable throughout, has left nothing where it once had place."</footnote>
# NEOBIOTA 2016 Conference Committees

## Scientific Committee

1. Christian Bohren, Agroscope, Nyon (CH)

2. Franz Essl, Umweltbundesamt, Wien (AT)

3. Emili García-Berthou, University of Girona (ES)

4. Piero Genovesi, INFS, IUCN, ISSG, Bologna (IT)

5. Phil Hulme, Lincoln University, Canterbury (NZ)

6. Johannes Kollmann, TU München (DE)

7. Ingo Kowarik, TU Berlin (DE)

8. Yves Krippel, Parc naturel de la Haute-Sûre (LU)

9. Darren Kriticos, CSIRO, Canberra (AU)

10. Ingolf Kühn, UFZ, Halle (DE)

11. Heinz Müller-Schärer, University of Fribourg (CH)

12. Petr Pyšek, Institute of Botany, CAS, Pruhonice (CZ)

13. Wolfgang Rabitsch, Umweltbundesamt, Wien (AT)

14. Christian Ries (coord.), National Museum of Natural History, Luxembourg (LU)

15. Helen Roy, CEH – NERC, Oxfordshire (UK)

16. Laurent Schley, Administration de la nature et des forêts, Diekirch (LU)

17. Uwe Starfinger, Julius-Kühn-Institut, Braunschweig (DE)

18. Montserrat Vilà, EBD-CSIC, Sevilla (ES)

## Organizing Committee

1. Jan Herr, Administration de la nature et des forêts, Diekirch (LU)

2. Alain Klein, Parc naturel de l'Our, Hosingen (LU)

3. Yves Krippel, Parc naturel de la Haute-Sûre, Esch/Sûre (LU)

4. Christian Ries (coord.), National Museum of Natural History, Luxembourg (LU)

5. Laurent Schley, Administration de la nature et des forêts, Diekirch (LU)

6. Simone Schneider, SICONA, Olm (LU)

7. Uwe Starfinger, Julius-Kühn-Institut, Braunschweig (DE)
NEOBIOTA 2016 - CONFERENCE PROGRAMME

Venue: Cultural centre Larei, Vianden, Luxembourg

All oral communications @ Main conference room

Poster spaces @ Sports Hall & Besseling Room & Gallery

Coffee breaks and Lunches @ Sports Hall

Wednesday, 14 September 2016

08:00 - 09:00 Registration @ Foyer

09:00 - 09:45 Conference opening
Christian Ries (Organizing Committee), Montserrat Vilà (Neobiota Consortium), Guy Arendt (Secretary of State for Culture), Carole Dieschbourg (Minister for the Environment), Marie-Claude Marx (National Research Fund Luxembourg).

**Keynote 1** *Biological invasions and climate change*. Chair: Franz Essl

09:45 - 10:30 We-K-01 Cascade Sorte
Will climate change increase the success and impacts of invasive species?

10:30 - 11:15 Coffee break

**Session 1** *Biological invasions and climate change*. Chair: Franz Essl

11:15 - 11:30 We-S1-01 - Caroline Müller
Impacts of drought and plant origin on growth and tolerance of the invasive perennial *Tanacetum vulgare*

11:30 - 11:45 We-S1-02 - Aníbal Pauchard, Jonas Lembrechts, Jonathan Lenoir, Martín Nuñez, Charly Geron, Arne Ven, Ivan Nijs, Ann Milbau
Using elevational gradients to understand plant invasions in cold environments: a field experiment in Sweden and Chile

11:45 - 12:00 We-S1-03 - Jesse Kalwij, Alexandra Erfmeier
Population dynamics of alien plants in a montane ecosystem

12:00 - 12:15 We-S1-04 - Huseyin Onen, Shahid Farooq, Hikmet Gunal, Cumali Ozaslan
Successful Adaptations to Adverse Environmental Conditions: More Areas under the Risk of Ragweed Invasion?

12:15 - 12:30 We-S1-05 - Miriam Zemanova, Olivier Broennimann, Antoine Guisan, Eva Knop, Gerald Heckel
Slug invasion and climate change: phylogenetics, interception records and climatic niche help elucidate global spread of *Arion* species

12:30 - 12:45 We-S1-06 - Matt Hill, Cleo Bertelsmeier, Susana Clusella-Trullas, Jeff Garnas, Mark Robertson, John Terblanche
Insect invasions under climate change: an agroecological perspective

12:45 - 14:00 Lunch & Poster session

13:10 - 13:50 EWRS information meeting @ Besseling Room (1st floor)
## Session 2
*Invader traits and characteristics of invaded communities.* Chair: Emili García-Berthou

14:00 - 14:15 We-S2-01 - Bruce Osborne, Margherita Gioria, Mauricio Mantoani
Early Growth and Development as a Key Defining Feature of Plant Invasions

14:15 - 14:30 We-S2-02 - Margherita Gioria, Petr Pyšek
Germination strategies and plant invasions: current knowledge, gaps and challenges

14:30 - 14:45 We-S2-03 - Andreas Menzel, Stefan Hempel, Stefan Klotz, Mari Moora, Petr Pyšek, Matthias Rillig, Martin Zobel, Ingolf Kühn
Mycorrhizal status interacting with morphological traits help explaining invasion success of alien plant species

14:45 - 15:00 We-S2-04 - Petr Pyšek, Jan Suda, Jan Cuda, Wen-Young Guo, Magdalena Lucanová, Hana Skálová, Laura Meyerson
One ring rules them all: genome size as a driver of invasiveness in plants

15:00 - 15:15 We-S2-05 - Samuel Levin, Claudia Stein, Tiffany Knight
Phylogenetic novelty alters the strength of biotic interactions for native and exotic plant species

15:15 - 15:30 We-S2-06 - Philip Hulme, Maud Bernard-Verdier
Linking divergence and dissimilarity in native and alien species traits to address invasions of plant communities

15:30 - 15:45 We-S2-07 - Jane Molofsky, Jan Divisek, Milan Chytry, Petr Pyšek, Brian Beckage, David Richardson, Nicholas Gotelli
Functional trait differences between native and invasive species across six habitats in the Czech Republic

15:45 - 16:00 We-S2-08 - Christien Steyn, Peter le Roux, Steven Chown, Mark van Kleunen, Wayne Dawson, Marten Winter, Franz Essl, Jan Pergl, Petr Pyšek. Holger Kreft, Patrick Weigelt, Michelle Greve
A biogeographical and functional approach to improve our understanding of alien plant species on Sub-Antarctic Islands

16:00 - 16:45 Coffee break

## Session 3
*Ecological impacts of biological invasions / Invader traits and characteristics of invaded communities.* Chair: Ingolf Kühn

16:45 - 17:00 We-S3-01 - Stefan Linzmaier, Jonathan Jeschke
Mechanisms of exploitation and interference competition in a novel invader – the marbled crayfish

17:00 - 17:15 We-S3-02 - William Allen, Sally Street, Isabella Capellini
How life history influences invasiveness across terrestrial vertebrate classes

17:15 - 17:30 We-S3-03 - Sabrina Kumschick
Alien species classification and missing data: impact matters
17:30 - 17:45 We-S3-04 - Lorenzo Lazzaro, Giuseppe Mazza, Lorenzo Lastrucci, Claudia Giuliani, Alessandra Lagomarsino, Silvia Landi, Giada D'Errico, Elena Tricarico, Roberta Pastorelli, Alberto Inghilesi, Giulia Torrini, Pio Roversi, Arturo Fabiani, Bruno Foggi
Multiple impacts caused by the invasive tree *Robinia pseudoacacia*: insights from soil chemical features to microarthropods, nematodes, microbial and plant communities

17:45 - 18:00 We-S3-05 - Colin Orians, Robert Schaeffer, Wilson Claire, Mauri Barrett, Carol Thornber, Evan Preisser
Interacting invasive herbivores on hemlock: Effects on chemistry, growth and phenology

18:00 - 18:15 We-S3-06 - Varos Petrosyan, Victor Golubkov, Nikolai Zavyalov, Zoya Goryainova, Natalia Dergunova, Andrey Omelchenko, Sergey Bessonov, Sergey Albov, Natalia Marchenko, Lyudmila Khlyap, Yuri Dgebuadze
The Eurasian (*Castor fiber* L.) and Canadian (*Castor canadensis* Kuhl) beavers in the European part of Russia: long-term population dynamics and interrelationships between the species

18:15 - 18:30 We-S3-07 - Marc Kenis
*Harmonia axyridis* in Europe: have we been too alarmist?

19:00 - 20:00 Neobiota Council meeting

20:00 - 23:00 Social meeting in cultural café @ Ancien Cinéma café-club

Thursday, 15 September 2016

08:00 - 09:00 Registration @ Foyer

**Keynote 2** *Biogeography and macroecology of invasions*. Chair: Philip Hulme

09:00 - 09:45 Th-K-02 - Mark van Kleunen
Pretty, hot and sometimes successful: naturalization potential of ornamental garden plants in a changing climate

**Session 4** *Biogeography and macroecology of invasions*. Chair: Philip Hulme

09:45 - 10:00 Th-S4-01 - Noëlie Maurel, Mark van Kleunen
Scaling up from local climate matching in gardens to continental naturalization success: the case of ornamental woody plants in Europe

10:00 - 10:15 Th-S4-02 - Christine Sheppard
Long-term dynamics of plant invasions: the role of residence time in determining invader performance

10:15 - 10:30 Th-S4-03 - Pavel Pipek, Petr Pyšek, Tim Blackburn
Newspaper Stars in Feathers – reconstruction of passerine invasion history in New Zealand

10:30 - 10:45 Th-S4-04 - Belinda Gallardo, Pablo González, Wilfried Thuiller, Petr Pyšek, Montserrat Vilà, Chriss Yesson
Macroecological patterns of Europe's 100 of the worst invasive species under current and future conditions
10:30 - 11:15 Coffee break

**Session 5** *Invasive species and changes in landuse / Biogeography and macroecology of invasions.* Chair: Helen Roy

11:15 - 11:30 Th-S5-01 - Franz Essl, Wayne Dawson, Holger Kreft, Petr Pyšek, Jan Pergl, Mark van Kleunen, Patrick Weigelt, Bernd Lenzner, Thomas Mang, Dietmar Moser, Stefan Dullinger, Marten Winter
The drivers of the level of plant invasions world-wide

11:30 - 11:45 Th-S5-02 - Hanno Seebens, Franz Essl, Bernd Blasius
Patterns and predictions of the global spread of alien species: The intermediate distance hypothesis

11:45 - 12:00 Th-S5-03 - Jonas Lembrechts, Jonathan Lenoir, Nina Roth, Tarek Hattab, MIREN Consortium, Ann Milbau, Ivan Nijs
Plant invasions in mountains: improving invasive species distribution models' performances by accounting for the road network

12:00 - 12:15 Th-S5-04 - Ana Montero-Castaño, Carolina Morales, Pablo González-Moreno, Montserrat Vilà, Marcelo Aizen
Influential factors across an invasion process: the invasion of the Scotch broom in Nahuel Huapi National Park (Argentina)

12:15 - 12:30 Th-S5-05 - Chad Jones
Patterns of plant invasions over 60 years in a developing forest

12:45 - 14:00 Lunch & Poster session

**Keynote 3** *Non-native pests and pathogens.* Chair: Wolfgang Rabitsch

14:00 - 14:45 Th-K-03 - Alison Dunn
Invasive Alien Species and Pathogens: interactions, impact and strategies for control

**Session 6** *Non-native pests and pathogens.* Chair: Wolfgang Rabitsch

14:45 - 15:00 Th-S6-01 - Stefan Schindler, Helen Bayliss, Mildren Adam, Wolfgang Rabitsch, Franz Essl, Hans-Peter Hutter, Peter Wallner, Swen Follak, Andrew Pullin
Alien species of human health concern: Evidence syntheses for impacts and management effectiveness

15:00 - 15:15 Th-S6-02 - Helen Roy
Exploring the barriers to predicting alien pathogen invasions

15:15 - 15:30 Th-S6-03 - Heinke Jäger, Alonso Carrion, Jacqueline Rodriguez, Denisse Barrera, Sabine Tebbich, Arno Cimadom, Christian Sevilla, Charlotte Causton
Restoration of a blackberry-invaded unique forest in Galápagos: impacts on the vegetation, birds and invertebrates

15:30 - 15:45 Th-S6-04 - Jennifer Fill, Brian van Wilgen, Johan Baard, Chad Cheney, Aurelia Forsyth, Greg Forsyth, Tineke Kraaij, David Le Maitre
Challenges to invasive alien plant control and ecosystem restoration in the Cape fynbos, South Africa
15:45 - 16:00 Th-S6-05 - Kylie Ireland, Rieks van Klinken, David Cook, David Logan, Lisa Jamieson, Joy Tyson, Philip Hulme, Susan Worner, Eckehard Brockerhoff, John Fletcher, Brendan Rodoni, Gabrielle Vivian-Smith, Rosa Crnov, Mark Whattam, Mandy Christopher, Barbara Hall, Rod Turner, David Teulon. Mike Hodda, Dean Paini
Plant pest impacts: A common set of metrics

16:00 - 16:45 Coffee break

16:45 - 18:30 Poster session @ Poster spaces

20:00 - 22:30 Conference dinner @ Vianden Castle - Vic Abens Room

20:00 - 23:00 Social meeting in cultural café @ Ancien Cinéma café-club

Friday, 16 September 2016

08:00 - 09:00 Registration @ Foyer

**Keynote 4** *Genetics and evolution of invasive species.* Chair: Petr Pyšek

9:00 - 09:45 Fr-K-04 - Carol E. Lee
Evolution of Osmoregulation Arising from Fluctuating Seas, and Implications for Invasions

**Session 7** *Genetics and evolution of invasive species.* Chair: Petr Pyšek

09:45 - 10:00 Fr-S7-01 - Frank Drygala, Alain Frantz
Using genetic tools to inference expansion pattern of the raccoon dog

10:00 - 10:15 Fr-S7-02 - Natalia Osten-Sacken, Mike Heddergott, Martin Runge, Alain Frantz
Using population genetics to understand the evolutionary potential of an introduced parasitic nematode, the raccoon roundworm (*Baylisascaris procyonis*)

10:15 - 10:30 Fr-S7-03 - Marion Javal, Alain Roques, Géraldine Roux
Exploring the invasion history of an exotic pest based on genetic markers: the case of the Asian long-horned beetle (*Anoplophora glabripennis*).

10:30 - 11:15 Coffee break

**Session 8** *Genetics and evolution of invasive species / Engaging the public with the topic on invasive species.* Chair: Ingo Kowarik

11:15 - 11:30 Fr-S8-01 - Tomasz Rewicz, Remi Wattier, Michal Grabowski, Thierry Rigaud, Tomasz Mamos, Karolina Bacela-Spychalska
Out of the Black Sea: Phylogeography of the invasive killer shrimp *Dikerogammarus villosus* across Europe

11:30 - 11:45 Fr-S8-02 - Giovanni Vimercati, Sarah Davies, John Measey
Never underestimate your opponent: adaptive phenotypic response in a recent invader
11:45 - 12:00 Fr-S8-03 - Cindy Verdu, Xavier Bouteiller, Emmi Aikio, Kasso Daïnou, Adline Delcamp, Oliver de Thier, Frédéric Gévaudant, Erwan Giuchoux, Yech'an Laizet, Philippe Lejeune, Coralie Mengal, Samuel Quevauvillers, Alexandre Raimbault, Raphaël Ségura, Ludivine Lassois, Arnaud Monty, Stéphanie Mariette, Annabel Porté
A multidisciplinary insight in *Robinia pseudoacacia* genetic and phenotypic diversity

12:00 - 12:15 Fr-S8-04 - Xenia Junge, Marcel Hunziker, Nicole Bauer, Arne Arnberger, Roland Olschewski, Daniel Fischer
Public and expert perception of invasive neobiota and development of neobiota communication tools

12:15 - 12:30 Fr-S8-05 - Charles Bargeron, Keith Douce, Joseph LaForest, David Moorhead
Smartphones: changing the way invasive species are reported

12:30 - 12:45 Fr-S8-06 - Ana Novoa, Susan Canavan, Cathleen Cybèle, Sarah Davies, Paul Downey, Mirijam Gaertner, Sjirk Sjirk, Charles Griffiths, Philip Ivey, Haylee Kaplan, Sabrina Kumschick, David Le Maitre, John Measey, Ana Nunes. David Richardson, Tamara Robinson, Ross Shackleton, Louise Stafford, Julia Touza, John Wilson
Engaging stakeholders on the management of invasive species: a step by step framework

12:45 - 14:00 Lunch & Poster session

**Keynote 5** *Eradication, management & control of invasive species*. Chair: Laurent Schley

14:00 - 14:45 Fr-K-05 - Christoph Kueffer
Managing biological invasions in the Anthropocene

**Session 9** *Eradication, management & control of invasive species*. Chair: Laurent Schley

14:45 - 15:00 Fr-S9-01 - Heinz Müller-Schärer, Bruno Chauvel, Gerhard Karrer, Gabriella Kazinczi, Per Kudsk, Alfons Oude Lansink, Urs Schaffner, Carsten Skjoth, Matt Smith, Maurizio Vurro, Letty de Weger, Yan Sun, Suzanne Lommen
Cross-fertilizing weed science and invasion science: *Ambrosia artemisiifolia* as an ideal bridge species

15:00 - 15:15 Fr-S9-02 - Suzanne Lommen, Caspar Hallmann, Eelke Jongejans, Heinz Müller-Schärer
Environmental drivers of European-wide variation in *Ambrosia* pollen and seed production, and implications for management of this invasive, allergenic species

15:15 - 15:30 Fr-S9-03 - Janine Saegesser, Daniel Fischer, Kathrin Fischer
Long-term control of *Impatiens glandulifera* in a Swiss Forest: does zero-tolerance pay off?
15:30 - 15:45 Fr-S9-04 - Pablo González-Moreno, Alex Brook, Kate Constantine, René Eschen, Daisuke Kurose, Corin Pratt, Nikolai Thom, Sarah Thomas, Richard Shaw
Making the psyllid work: the biological control of Japanese knotweed in England and Wales as a study system to understand and manage biological invasions

15:45 - 16:00 Fr-S9-05 - Pauline Palmas, Elsa Bonnaud, Raphaël Gouyet, Malik Oedin, Alexandre Millon, Corentin Chaillon, Frédéric Rigault, Jean-Jérôme Cassan, Eric Vidal
How to deal with cat (*Felis silvestris catus*) management on a large and inhabited island?

16:00 - 16:45 Coffee break

**Session 10**
*Eradication, management & control of invasive species / Biosecurity and risk assessment, including early detection and rapid response.* Chair: Uwe Starfinger

16:45 - 17:00 Fr-S10-01 - Simone Lioy, Marco Porporato, Daniela Laurino, Aulo Manino, Sandro Bertolino
Spread of *Vespa velutina* in Italy: natural diffusion, human-mediated dispersion and monitoring intensity to improve the management activities

17:00 - 17:15 Fr-S10-02 - Spyridon Flevaris
EU Regulation on invasion alien species

17:15 - 17:30 Fr-S10-03 - Montserrat Vilà, Pablo González-Moreno, Marc Kenis, et al.
Consistency of impact risk assessments across assessors

17:30 - 17:45 Fr-S10-04 - Sonia Vanderhoeven, Etienne Branquart, Bram D'hondt, Phil Hulme, Assaf Schwartz, Diederik Strubbe, Anne Turbé, Niall Moore, Jim Casaer, Hugo Verreycken, Tim Adriaens
Beyond protocols: improving the reliability of expert-based risk analysis underpinning invasive species policies

17:45 - 18:00 Fr-S10-05 - Katelyn Faulkner, Mark Robertson, Mathieu Rouget, John Wilson
Prioritising surveillance for alien organisms transported as stowaways on ships

18:00 - 18:15 Fr-S10-06 - Irene Adrian-Kalchhauser, Patricia Burkhardt-Holm
Detection of invasive gobies by probing freshwater samples for DNA traces

18:15 - 18:30 Fr-S10-07 - Katriona Shea, Ciara Hovis, Joseph Keller, Brittany Teller, Ruth Hufbauer
Parsing Propagule Pressure: The effects of multiple aspects of propagule pressure on the success of the invasive musk thistle *Carduus nutans*

18:30 - 19:00 Conference closing
Jan Herr (Poster award), Christian Ries (Organizing Committee), Bruce Osborne (10th Neobiota conference 2018 in Ireland), Montserrat Vilà (Neobiota Consortium).

20:00 - 23:00 Social meeting in cultural café @ Ancien Cinéma café-club

**Saturday, 17 September 2016**

09:00 - 17:00 Field trip

20:00 - 23:00 Social meeting in cultural café @ Ancien Cinéma café-club
Oral Presentations
**Keynote 1 - Biological invasions and climate change**

We-K-01

**Will climate change increase the success and impacts of invasive species?**

Cascade Sorte

Department of Ecology and Evolutionary Biology, University of California, Irvine, United States

Climate change and biological invasions are two of the greatest threats to global biodiversity and ecosystem functioning. Both climate change and invasions have, individually, caused population declines and local extinctions of native species. Furthermore, these threats may not be independent, leading to a “double whammy” for native species if they are simultaneously impacted by climate change and invasive species both *directly* and *indirectly*, e.g., via climate-driven increases in invasive species or invasive species impacts on the ability of natives to cope with climate change. In my talk, I address the hypothesis that climate change and species invasions will interact, to the detriment of native species. First, I ask: will invasive species be favored over native species under changing climatic conditions? Secondly, will climate change increase the impacts of invasive species on native species? I draw conclusions from empirical data and results of meta-analyses and syntheses conducted as part of two international, cross-ecosystem working groups. Together, these findings suggest that climate change is likely to increase the success and impacts of many invasive species. However, the threat varies across taxa, ecosystems, and regions, highlighting the importance of localized prevention and management efforts and scope for restoration under future change.

Keywords: climate change, extreme events, impacts, prediction, horticulture, marine, terrestrial
Session 1 - Biological invasions and climate change

We-S1-01

# Impacts of drought and plant origin on growth and tolerance of the invasive perennial *Tanacetum vulgare*

Caroline Müller

Bielefeld University, Department of Chemical Ecology, Universitätsstr. 25, Bielefeld, Germany

Abiotic conditions such as increased drought events expected due to climate change as well as numerous biotic factors, including human activities, potentially select for trait changes in invasive organisms. One of the key hypotheses in invasion biology postulates that invasive plant populations show an increased phenotypic plasticity compared to their native counterparts, which may be advantageous. We investigated how plants of different origin respond in growth, regrowth and various leaf traits to drought. Therefore, we grew 18 populations of the perennial plant *Tanacetum vulgare* with different range expansion (North America, invasive; West Europe, archaeophyte; East Europe, native) in competition with the common grass *Poa pratensis* under two irrigation treatments (dry and control) in a common garden. Aboveground biomass was cut once and regrowth as measure of tolerance evaluated under constant water conditions. The phenotypic plasticity of life-history traits in response to these treatments was determined. The irrigation treatment had only little effect on plant traits of *T. vulgare* in the first growing period. However, at regrowth plants originally exposed to dry conditions grew more vigorously. In contrast, the grass produced less biomass in response to drought before and after cutting, being thus more sensitive to drought. Contrary to our expectations, phenotypic plasticity was not higher in plants of the invasive populations and even reduced in one trait, which may be due to ecological constraints in a complex environment. Several traits such as tolerance differed between plants from different regions, reflecting in part the likely introduction pathway from East to West Europe and from there to North America. Significant effects of latitude, as indicator for climate conditions, on traits were more pronounced in plants of the native origin, whereas in invasive populations, local adaptations may be interfered by genetic admixture. Our study highlights the need to test the responsiveness of plant traits from native *versus* invasive populations in complex environments, including various stress factors. Furthermore, it demonstrates the importance of considering the range expansion and origin of populations as important factors influencing trait expression and plasticity.

Keywords: common garden, competition, phenotypic plasticity, regrowth, terpenoids, tolerance
**Using elevational gradients to understand plant invasions in cold environments: a field experiment in Sweden and Chile.**

Aníbal Pauchard<fnref n="1" />, Jonas Lembrechts<fnref n="2" />, Jonathan Lenoir<fnref n="3" />, Martín Nuñez<fnref n="4" />, Charly Geron<fnref n="2" />, Arne Ven<fnref n="2" />, Ivan Nijs<fnref n="2" />, Ann Milbau<fnref n="5" />

Plant invasions into cold environments are a growing threat to biodiversity. Mountains and high latitude environments are becoming increasingly invaded because of higher human-induced propagule pressure and disturbances, and lower climatic barriers due to global warming. Mountains in high latitudes may serve as good natural climatic gradients to understand which are the most relevant drivers of plant invasions into cold environments. We used a multifactorial field experiment to test how human-mediated (i.e. disturbance, nutrient addition and propagule pressure) and climatic factors influence the outcome of an invasion. The experiment encompassed sites in Sweden and Chile to increase the power of generalization. In 1-m2 plots located at low, medium and high elevation in three mountains in each study site, we seeded non-native plants known to occur in each region. The experiment included two levels of propagule pressure (5 and 30 seeds), nutrient addition and control (non-addition), and disturbance (removal of vegetation) and control (non-removal). We show how invader success (growth and reproduction) showed a quadratic correlation with elevation. Plants were bigger and more reproductive at mid elevation, which may be due to competition with the surrounding vegetation? at low elevations and cold climate at high elevations. Although Sweden and Chile have very different biogeographic and historical contexts, this pattern was held for both regions. Disturbance turned out to be the main driver of invader success besides elevation, with high nutrient levels playing an additional role in biomass and flower production. At this small scale, the role of propagule pressure was negligible, especially towards later stages of invader development. We thus argue that mountains are likely to see rapid increases in plant invasions in the near future, with temperatures, disturbance and human influence on the rise. Our results suggest that even though climate change is already a reality in cold environments, preventive measures should play an important role by reducing human disturbances in mountains. This research emphasizes the importance of having a global monitoring network of plant invasions in cold environments to inform managers and policy makers about critical decisions to control plant invasions.

Funding provided by the Swedish Research Council (VR 2012-6252) to AM, AP and MAN and by the Research Foundation - Flanders (FWO) to JJL. AP funded by grants ICM P05-002 and PFB-23 of the Institute of Ecology and Biodiversity.

Keywords: altitude, biosecurity, global warming, subpolar regions

<footnote n="1">¹Facultad de Ciencias Forestales, Universidad de Concepción & Instituto de Ecología y Biodiversidad (IEB), Concepción, Chile</footnote>

<footnote n="2">²Department of Biology, University of Antwerp, Wilrijk, Belgium</footnote>

<footnote n="3">³UR "Ecologie et Dynamique des Systèmes Anthropisés" (EDYSAN, FRE 3498 CNRS-UPJV), Université de Picardie Jules Verne, Amiens, France</footnote>

<footnote n="4">⁴Laboratorio Ecotono, INIBIOMA, CONICET, Universidad Nacional del Comahue, Bariloche, Argentina</footnote>

<footnote n="5">⁵Department of Biodiversity and Natural Environment, Research Institute for Nature and Forest INBO, Brussels, Belgium</footnote>
# Population dynamics of alien plants in a montane ecosystem

Jesse Kalwij<fnref n="1" />,<fnref n="2" />, Alexandra Erfmeier<fnref n="1" />,<fnref n="3" />

Our knowledge and understanding of population dynamics of invasive species in montane ecosystems is limited, mostly due to a shortage of suitable datasets. An exception is provided by a monitoring project in the Drakensberg, South Africa (Kalwij et al. 2008, Kalwij et al. 2015). This project, running since 2007, showed that alien plant species are ascending at unprecedented rates (annual ascents of 9.7 m/yr for perennials (N = 26) and 24.5 m/yr for annuals (N = 17). While Kalwij and colleagues collected data from the altitudinal range margin of species, it remains unclear whether species can complete their life cycle in these range margins. This study aims to fill that gap by also collecting data on the life stage of aliens. This enables differentiating between the core altitudinal distribution range (i.e., where species can complete their life cycle) and the altitudinal periphery of species ranges. The current monitoring protocol prescribes recording the three highest altitudinal observations of each alien species in the verges of the Sani Pass road, along an altitudinal gradient of 1,500–3,200 m a.s.l. We complemented this protocol with the highest altitudinal observations of flowering and seed-producing alien plants in January and March 2016. We found 84 exotic plant species, 63 of which were observed with seeds. For annuals, highest observed individuals were at significantly higher altitudes than flowering individuals by 104.5 m (t = 2.476, df = 35, P = 0.018), but there was no difference between flowering and seed-bearing plants (t = 1.671, df = 34, P = 0.104). For perennials, however, there was no significant difference in altitude between either of the life cycle stage pairs. These results show that exotic species can complete their life cycle even at very high altitudes, suggesting that their ecological range margin is relatively small. An altitudinal range shift, whether due to climate change or in response to anthropogenic disturbance, would therefore have a significant effect on the impact of exotic species in montane ecosystems.

Keywords: established range; potential range; range edge; Sani Pass; South Africa

<footnote n="1">¹Institute for Ecosystem Research – Geobotany, Kiel University, Kiel, Germany</footnote>

<footnote n="2">²DST-NRF Centre of Excellence for Invasion Biology, Department of Zoology, University of Johannesburg, Auckland Park, South Africa</footnote>

<footnote n="3">³German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig, Germany</footnote>
# Successful Adaptations to Adverse Environmental Conditions: More Areas under the Risk of Ragweed Invasion?

Huseyin Onen<fnref n="1" />, Shahid Farooq<fnref n="1" />, Hikmet Gunal<fnref n="2" />, Cumali Ozaslan<fnref n="3" />

Common ragweed (Ambrosia artemisiifolia L.) is an allergenic plant currently invading considerable portion of Europe. The species distribution modeling indicates that temperature will be the most limiting factor for the further spread of ragweed in Europe. Although climate predictions estimate that aridity and salinity will globally increase in the coming decades, abiotic stresses such as drought and salinity have rarely been considered in modeling the potential spread of the plant. In the current study seedling survival, growth and nutrient uptake of ragweed were tested under five available water contents (100, 75, 50, 25 and 12.5% available water based on field capacity) and four soil salinity levels (0, 3, 6 and 12 dSm⁻<fnref n="1" />) in greenhouse experiments. Experiments were conducted according to a randomized complete block design with 5 replications. The results indicated that all the transplanted seedlings successfully survived under the experimental conditions tested except severe water deficiency (12.5% available water) and the highest level of salinity (12 dSm⁻<fnref n="1" />). The growth and reproductive outputs of the plant were decreased with increasing water deficit and salinity level. However, all surviving plants have produced seeds. A sharp decline in reproductive output of the plant was observed under 25 and 12.5% available water treatments, and 6 and 12 dSm⁻<fnref n="1" /> salinity levels. The ragweed used different strategies to cope with adverse environmental conditions such as increased uptake of K, maintained higher K/Na and root-to-shoot ratios and early flowering. It is concluded that ragweed can successfully adapt to changing climate and expand its range in the currently invaded regions. Local populations adapted to low water availability and high salinity levels may cause severe problems in natural and agricultural ecosystems. However, further studies on the genetics of stress tolerance are needed to identify the genes and mechanisms behind the increased tolerance of ragweed to adverse environmental conditions.

This study was funded by TUBITAK with grant number 113 O 790 as a part of Cost Action TD-1209. The results also address the major challenges focused by Cost Action FA-1203

Keywords: Common ragweed, abiotic stress tolerance, growth, invasion

<footnote n="1">¹Department of Plant Protection, Faculty of Agriculture, Gaziosmanpasa University, Tokat, Turkey</footnote>

<footnote n="2">²Department of Soil Science and Plant Nutrition, Faculty of Agriculture, Gaziosmanpasa University, Tokat, Turkey</footnote>

<footnote n="3">³Department of Plant Protection, Faculty of Agriculture, Dicle University, Diyarbakır, Turkey</footnote>
# Slug invasion and climate change: phylogenetics, interception records and climatic niche help elucidate global spread of *Arion* species

Miriam Zemanova<fnref n="1" />, <fnref n="2" />, Olivier Broennimann<fnref n="3" />, Antoine Guisan<fnref n="3" />, <fnref n="4" />, Eva Knop<fnref n="2" />, Gerald Heckel<fnref n="1" />, <fnref n="5" />

Global trade increases the rate of biological invasions, which are causing severe problems to native ecosystems. It is therefore important to establish the routes of invasive species introduction if we are to prevent new ones. The situation might be exacerbated by climate change, which can influence the suitability of climatic conditions for the invasive species, often by increasing the amount of suitable locations. However, the opposite situation could also occur, even though this has not been reported very often. Here, we focus on three *Arion* slug species introduced to Northern America and Australia, for which the potential for global spread has never been assessed. We combined interception records, genetics and species distribution modelling to assess their introduction history and to predict which regions are of the highest risk of future invasions. We examined the genetic diversity within samples and geographic regions with two mitochondrial DNA markers. We also inferred the worldwide potential distribution of *Arion* sp. under current climatic conditions and two future timeframes using climate change scenarios and an ensemble of four different modelling techniques. We found extensive haplotype sharing among continents, and evidence of anthropogenic movement within the area of introduction. In concordance with the genetic analyses, interception records suggest that these slugs get introduced to the USA and Australia primarily from France, the Netherlands and the UK, but also from other locations in North America. Surprisingly, under the future climate scenarios, the amount of regions with suitable environmental conditions for the three species is likely to decrease and shift towards the North. However, given the potential significant impact of this invasion, the efforts to prevent new introductions should not be ceased.

Keywords: invasive species, molluscs, species distribution modelling

<footnote n="1">¹Computational and Molecular Population Genetics Group, Institute of Ecology and Evolution, University of Bern, Bern, Switzerland</footnote>

<footnote n="2">²Community Ecology Group, Institute of Ecology and Evolution, University of Bern, Bern, Switzerland</footnote>

<footnote n="3">³Spatial Ecology Group, Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland</footnote>

<footnote n="4">⁴Institute of Earth Sciences, University of Lausanne, Lausanne, Switzerland</footnote>

<footnote n="5">⁵Swiss Institute of Bioinformatics, Lausanne, Switzerland</footnote>
# Insect invasions under climate change: an agroecological perspective

Matt Hill<fnref n="1" />,<fnref n="2" />, Cleo Bertelsmeier<fnref n="3" />, Susana Clusella-Trullas<fnref n="4" />, Jeff Garnas<fnref n="5" />, Mark Robertson<fnref n="6" />, John Terblanche<fnref n="2" />

Climate change affects the rate of insect invasions as well as the abundance, distribution and impacts of such invasions on a global scale. Among the principal analytical approaches to predicting and understanding future impacts of biological invasions are Species Distribution Models (SDMs) and other forms of niche models. One niche modelling approach, the semi-mechanistic platform CLIMEX, is able to employ information on ecophysiological traits, abundance data and observed distributions to model the species relationship with climate. This combination of inductive and deductive methods to fit model parameters allows CLIMEX to avoid some of the issues of extrapolation which are a major pitfall of correlative based SDMs. CLIMEX is therefore highly applicable to investigating biological invasions in the context of climate change.

The tephritid fruit flies (Diptera: Tephritidae) comprise some of the most successful invasive species and serious economic pests around the world. As such there have been numerous modelling attempts for a number of particularly injurious species. Here we collate individually parametrized CLIMEX models from the literature for 12 tephritid species. We project these models into both present and future climate scenarios to examine overall patterns of climate suitability and forecast potential global distributional changes for this group. We further compare the aggregate response of the group against species-specific responses. Climate change is predicted to decrease global climate suitability and to shift the cumulative distribution poleward for the group of tephritid species examined here. However, when examining species-level patterns, the predominant directionality of range shifts for 11 of the 12 species is globally eastward, resulting in different degrees of species turnover at a regional level.

Whilst it is a relatively straight forward exercise to produce such maps of global distribution patterns, disconnect exists between predicting changes in invasion potential and providing management options for farmers. We explore how indices relating to trade and fruit production can be used to help understand patterns of risk and then then discuss future directions for how maps of invasion potential may be made useful to inform management strategies both now and under future climate change.

Keywords: Climate change, Trade, Food security, Fruit flies, Tephritidae, Species distribution modelling

<footnote n="1">¹CSIRO Agriculture, Canberra, Australia</footnote>

<footnote n="2">²Centre for Invasion Biology, Department of Conservation Ecology and Entomology, Faculty of AgriSciences, Stellenbosch University, Stellenbosch, South Africa</footnote>

<footnote n="3">³Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland</footnote>

<footnote n="4">⁴Centre for Invasion Biology, Department of Botany and Zoology, Faculty of Science, Stellenbosch University, Stellenbosch, South Africa</footnote>

<footnote n="5">⁵Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa</footnote>

<footnote n="6">⁶Centre for Invasion Biology, Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa</footnote>
Session 2 - Invader traits and characteristics of invaded communities

We-S2-01

**Early Growth and Development as a Key Defining Feature of Plant Invasions**

Bruce Osborne¹, Margherita Gioria², Mauricio Mantoani³

¹UCD School of Biology and Environmental Science and UCD Earth Institute, University College Dublin, Belfield, Dublin, Ireland

²Margherita Gioria, Institute of Botany, The Czech Academy of Sciences, Pruhonice, Prague, Czech Republic

³Mauricio Mantoani, UCD School of Biology and Environmental Science and UCD Earth Institute, University College Dublin, Dublin, Ireland

Despite more than two decades of investigation the trait(s) associated with successful plant invasions remain largely elusive. Although there is evidence that some traits may be important for plant invasions many may be context-specific making generalisations difficult. There is increasing evidence, however, that early growth and development could be a defining characteristic of plant invasions. Plant invaders can initiate growth and development up to three weeks before resident species and there may be at least three ways to achieve this. Growth is either initiated in the autumn 'window' and plants over winter in a semi dormant state subsequently initiating growth the following year and/or the development of storage reserves during the autumn provide resources for earlier development in the spring 'window'. For annual invaders that complete their life cycle in the same year growth and development appears to occur without a reliance on stored reserves but occurs rapidly after seed germination. A key feature of these strategies is that the acquisition of limiting essential resources, such as nitrogen and water, to support early leaf growth and development, is possible under sub optimal environmental conditions, and that growth is largely photoperiod-insensitive with little or no chilling requirement. A largely temperature-related control of the early initiation of growth and development may also explain why invasive plant species often exhibit a greater response to climate change-related factors, particularly the increased length of the growing season. In contrast, a high maximum growth rate during early season growth appears to be less important.

Whilst there are several examples of early growth in introduced species there are few comparative examples where any benefits can be directly assessed, although data on the contrasting invaders cheat grass (Bromus tectorum) and Gunnera is consistent with advantages associated with early growth and an ability to acquire limiting resources under sub-optimal conditions. The recognition that early growth and the exploitation of a period when plant-plant interactions are low may also explain the often equivocal evidence for invasive plant species having a superior competitive ability. What is puzzling, however, is why resident species initiate growth later, unless this strategy has proved more successful in the longer-term.

Keywords: early growth, resource-use, sub-optimal conditions, Gunnera
# Germination strategies and plant invasions: current knowledge, gaps and challenges

Margherita Gioria<fnref n="1" />,<fnref n="2" />, Petr Pyšek<fnref n="1" />,<fnref n="3" />

Germination patterns strongly affect the fitness and survival of a plant, its evolutionary potential, and the timing of competition among neighboring individuals/species. To improve our understanding of their significance in plant invasions, we synthesize the findings of studies examining a range of germination patterns (time to germination, germination rates, and germination percentages/ratios), under a range of environmental conditions. These patterns were compared for (1) invasive alien and non-invasive alien congeners, (2) invasive alien species and native species/congeners, (3) invasive and non-invasive congeners in their native range, and (4) invasive species in their native and non-native range. Experimental evidence indicates that invasive species germinate consistently earlier and more rapidly (lower time to germination and higher germination rates) compared to non-invasive congeners and co-occurring native species in their non-native range. Moreover, invasive species germinated consistently earlier or more rapidly in their non-native range, although the role of adaptation, plasticity or genetic variation in determining such patterns has been rarely assessed. Pre-adaptation resulting in earlier/rapid germination was also reported as an important factor in the naturalization or invasiveness of several species. In contrast, germination percentages (final or 50% germination) were higher, similar or even lower for invasive species compared to non-invasive or less invasive congeners, or to native species/congeners, suggesting that a high germination percentage is not a reliable predictor of invasiveness. The generality of these patterns and the need for additional observational and experimental studies, focusing on germination as a crucial stage in the naturalization and persistence of invasive species, are discussed.

Keywords: dormancy, germination, invasiveness, invasibility, soil seed bank

<footnote n="1">¹Institute of Botany, Department of Invasion Ecology, The Czech Academy of Sciences, Pruhonice, Czech Republic</footnote>

<footnote n="2">²UCD School of Biology and Environmental Science, University College Dublin, Dublin, Ireland</footnote>

<footnote n="3">³Department of Ecology, Faculty of Science, Charles University in Prague, Prague, Czech Republic</footnote>
# Mycorrhizal status interacting with morphological traits help explaining invasion success of alien plant species

Andreas Menzel<fnref n="1" />, Stefan Hempel<fnref n="2" />, Stefan Klotz<fnref n="1" />, Mari Moora<fnref n="3" />, Petr Pyšek<fnref n="4" />, Matthias Rillig<fnref n="2" />, Martin Zobel<fnref n="3" />, Ingolf Kühn<fnref n="1" />

It is still debated whether alien plants benefit from being mycorrhizal, or if engaging in the mycorrhizal symbiosis constrains their establishment and spread in new regions. Here, we analyzed the association between mycorrhizal status of alien plant species in Germany and their invasion success. We compared whether the representation of species with different mycorrhizal status (obligate, facultative or non-mycorrhizal) differed at several stages of the invasion process. Furthermore, we used generalised linear models to explain the range in Germany, incorporating interactions of mycorrhizal status with additional plant traits related to morphology, reproduction, and life-history. Non-naturalized aliens did not differ in their relative frequency of mycorrhizal status from naturalized aliens. Mycorrhizal status significantly explained the occupied geographical range, with facultative mycorrhizal species occupying a larger range than non-mycorrhizal aliens and obligate mycorrhizal plant species taking an intermediate position. Additionally, aliens with storage organs, shoot metamorphoses or specialized structures promoting vegetative dispersal on the expense of high carbon and energy demand, occupied a larger range if being facultative mycorrhizal. We conclude that being mycorrhizal is important for the establishment and persistence of aliens in Central Europe and constitutes an advantage compared to non-mycorrhizal plants. Being facultative mycorrhizal seems to be especially advantageous for successful spread, as the flexibility of this mycorrhizal status may lead to a broader set of ecological strategies. Still it seems that facultative mycorrhizal neophytic species benefit from trade-offs with other traits related to high carbon cost, such trade-offs are almost absent from natives. This indicates that natives and neophytes benefit differently from the symbiosis and that the benefits received by natives are independent of carbon allocation.

Keywords: alien plants, biological invasion, Central Europe, floristic status, functional traits, MycoFlor, mycorrhizal status, trait interactions

<footnote n="1">¹Helmholtz Centre for Environmental Research - UFZ, Dept. Community Ecology, Halle, Germany</footnote>

<footnote n="2">²Freie Universität Berlin, Institute of Biology, Dahlem Center for Plant Sciences, Berlin, Germany</footnote>

<footnote n="3">³University of Tartu, Institute of Ecology and Earth Sciences, Tartu, Estonia</footnote>

<footnote n="4">⁴Institute of Botany, Department of Invasion Ecology, The Czech Academy of Sciences, Pruhonice, Czech Republic</footnote>
**One ring rules them all: genome size as a driver of invasiveness in plants**

Petr Pyšek<fnref n="1" />, <fnref n="2" />, Jan Suda<fnref n="1" />, <fnref n="3" />, Jan Čuda<fnref n="1" />, <fnref n="2" />, Wen-Young Guo<fnref n="1" />, Magdalena Lučanová<fnref n="1" />, Hana Skálová<fnref n="1" />,
Laura Meyerson<fnref n="4" />

The ecological role of genome size in plant invasion research has garnered increasing attention with the rapid development of screening methods and technology associated with measuring cytological characteristics. Knowledge gained from studies analyzing large numbers of species suggests that (i) across angiosperms, small genomes are disproportionately over-represented in invasive taxa. (ii) Within the subset of 128 globally most invasive species there was a higher frequency of species with very small genomes and a lack of large genomes among invasives, compared with their non-invasive congeners (Suda et al. 2015). (iii) Invasiveness is negatively correlated with genome size but positively with ploidy level, and it is their interaction that underlies their actual effects on invasion success (Pandit et al. 2014). (iv) If stages of invasion are taken into account, small genome seems to be an attribute of naturalized, not necessarily invasive congeners within the pairs they formed with non-invasives (Kubešová et al. 2010).

In this paper, we discuss the above results, but we also present the first study that explores the role genome size in promoting invasiveness in a framework that fundamentally differs from the multi-species studies in (i) focusing on differences in monoploid genome size at the population level, (ii) testing how the effects of genome size hold in interactions with other plant traits. To address these issues, we studied multiple factors assumed to affect plant invasiveness in a grass species *Phragmites australis*. In a common garden experiment, we grew native and invasive populations from Europe and North America for three years under standardized conditions, and measured a wide range of plant traits related to demography and population dynamics, herbivory, physiology and karyology. Several important variables were most relevant for the classification of invasive vs non-invasive populations based on the random forest algorithm: monoploid genome size, below- and above-ground biomass ratio, number of shoots, rhizome length and biomass, seasonality of climate in the region from which the population was sampled, and herbivory by aphids. However, the decision tree identified monoploid genome size as the only important variable separating invasives below the 1Cx-value of 0.53 pg. That genome size is retained as one of the most important factors also in a complex model including other factors potentially affecting invasiveness is an important finding providing strong support for exploring genome-size research avenue in plant invasions.

Keywords: population invasiveness, genome size, Phragmites australis

<footnote n="1">¹Institute of Botany, The Czech Academy of Sciences, Pruhonice, Czech Republic</footnote>

<footnote n="2">²Department of Ecology, Faculty of Science, Charles University in Prague, Prague, Czech Republic</footnote>

<footnote n="3">³Department of Botany, Faculty of Science, Charles University in Prague, Prague, Czech Republic</footnote>

<footnote n="4">⁴Department of Natural Resources Science, University of Rhode Island, Kingston, United States</footnote>
# Phylogenetic novelty alters the strength of biotic interactions for native and exotic plant species

Samuel Levin<fnref n="1" />, Claudia Stein<fnref n="2" />, Tiffany Knight<fnref n="1" />, <fnref n="3" />, <fnref n="4" />

Patterns of phylogenetic relatedness within communities have been widely used to infer the importance of different ecological and evolutionary processes during community assembly and invasion processes. Novel exotic plants are expected to have less niche overlap with resident plant species and have novel defense traits. Therefore, the population dynamics of exotic plant species are expected to be less influenced by competitors and enemies. However, novel exotic plant species might also interact less strongly with resident mutualists, and this is expected to reduce the observed population growth rate of exotic plant species. Finally, it is expected that closely related native and exotic plant species will have similar strengths of biotic interactions and population dynamics, but this idea has not been thoroughly evaluated. While many studies have examined the relationships between phylogenetic novelty (or functional trait novelty) and invasiveness of exotic plant species, much fewer have examined the mechanisms that might underlie these patterns. Here we provide a comprehensive test of the relationship between phylogeny, the strength of biotic interactions, and population dynamics for eight exotic and three native plant species occurring at a single field site near St. Louis, Missouri, USA. We collected demographic data for each plant species and projected per capita growth rates under the following experimental treatments: above-ground competitor removal, above-ground insect herbivore removal, below-ground fungi removal, below-ground insect herbivore removal. We found the strongest correlation among phylogenetic relatedness and competitor removal, in a way that more closely related species benefited more strongly from release of aboveground competition compared to novel (distantly related) species. The effects of other treatments were more idiosyncratic, being highly important for one or two plant species but not showing general effects or patterns with phylogeny. This result indicates that more novel species compete less strongly with resident species in the community, and highlights the importance of competitive interactions for community and invasion dynamics.

Keywords: Darwin's Naturalization Hypothesis, competition, demography, functional traits, phylogeny, population projection modeling

<footnote n="1">¹Martin-Luther-Universität, Halle, Germany</footnote>

<footnote n="2">²Washington University in St Louis, St Louis, United States</footnote>

<footnote n="3">³German Center for Integrative Biodiversity, Leipzig, Germany</footnote>

<footnote n="4">⁴Department of Community Ecology, UFZ, Helmholtz Centre for Environmental Research, Halle, Germany</footnote>
# Linking divergence and dissimilarity in native and alien species traits to address invasions of plant communities

Philip Hulme, Maud Bernard-Verdier

Bio-Protection Research Centre, Lincoln, New Zealand

A frequent question in plant ecology is whether the traits of alien plant species differ from natives and what underpins trait similarity or difference. This question has increasingly been addressed at the plant community scale and linked to broader theory regarding the role of trait convergence and divergence on community assembly, limiting similarity and habitat filtering.

While superficially similar, trait convergence and divergence are not equivalent concepts to trait dissimilarity. Trait divergence and convergence addresses attributes relating to the distribution of traits within assemblages of co-occurring species (overlap and variance) while trait dissimilarity tests for differences among groups of species (mean or median). Quantitative examples from the literature are re-analyzed to highlight how the failure to make this distinction in trait comparisons of co-occurring alien and native plants hinders the integration of biological invasions within a plant community context.

This distinction is critical since the extent of trait convergence or divergence within native and alien assemblages is essential to place trait dissimilarity into a community context, since it may highlight whether aliens are exploiting regions of trait space unfilled by natives. Assessment of trait dissimilarity solely through comparisons of differences in trait means and variances between native and alien species may miss critical differences in trait convergence and divergence that might shed light on community assembly. A series of schematic models are presented to highlight the need to distinguish between trait divergence and dissimilarity. The extent to which these map on to real-world examples is discussed.

To address these limitations, community approaches need to quantify the distribution of a priori identified traits within communities along suitable gradients and test hypothetical trait patterns against appropriate null models. The infrequent application of such approaches may explain the limited generalizations regarding the drivers and consequences of plant invasions at the community scale. Plant invasions are dynamic processes where the trait distributions of both alien and native species may be expected to change over time through competitive exclusion as well as contemporary evolution. Repeated surveys of both species abundance and their traits are required to predict the consequences of trait dissimilarity and divergence between aliens and natives for plant community assembly.

Keywords: assembly rules, coexistence, CSR, exotic, invasion ecology, limiting similarity, niche difference, SLA, weed
# Functional trait differences between native and invasive species across six habitats in the Czech Republic

Jane Molofsky<fnref n="1" />, Jan Divisek<fnref n="2" />, Milan Chytry<fnref n="2" />, Petr Pyšek<fnref n="3" />, Brian Beckage<fnref n="1" />, David Richardson<fnref n="4" />,
Nicholas Gotelli<fnref n="1" />

Invasive species may be invasive because they are similar to native species or alternatively they may be invasive by exploiting a separate niche. Here we investigate the relationship between plant invasion status (Native, Naturalized or Invasive) and species traits using a countrywide data from the Czech Republic. The data set contains 5950 species of which 4984 are classified as native, 784 are classified as naturalized (non-native but not spreading) and 182 are designated as invasive (non-native and spreading). Each species in the data set was matched with species level plant functional traits. We focused our analyses on three life history traits: height, specific leaf area (SLA) and germinule weight because these traits encapsulate three independent axes for plant life history evolution (Westoby 1998). The species data was further broken down into six unique habitats: grassland, ruderal, scree, wetland, scrub and forest. Our analysis of single traits indicated that invasive species were significantly different for both height and germinule weight in 5 of 6 habitats but for only 2 habitats for specific leaf area. The direction of the difference was only consistent for height data; when significant, invasive plants were taller than native plants. To examine life history strategies and potential trade-offs, we combined the trait data into a multi-dimensional niche index using non-metric multidimensional scaling (NMDS) and subsequently analyzed the distance between the native multi-dimensional trait index and the invasive multi-dimensional trait index using a cumulative density function that measured the distance of the invasive NMDS from the centroid of the native NMDS trait space. Using this more integrated measure, we find that five of six habitats show that the invasive species trait space occurs farther away from the center of the native species centroid trait distribution than expected by chance; further, the only non-significant habitat, wetlands, followed the pattern but was not statistically significant. Thus it appears that that invasive species occupy a multi-dimensional trait space at the outer edge of the native trait space; this occurrence at the boundary of the niche space implies that invasive species are successful because they are beating the native species at their own game, rather than exploiting a unique strategy.

Keywords: invasive, native, naturalized, life history theory, Czech Republic, habitats

<footnote n="1">¹University of Vermont, Burlington, United States</footnote>

<footnote n="2">²Masaryk University, Brno, Czech Republic</footnote>

<footnote n="3">³Academy of Sciences of the Czech Republic, Pruhonice, Czech Republic</footnote>

<footnote n="4">⁴Stellenbosch University, Stellenbosch, South Africa</footnote>
# A biogeographical and functional approach to improve our understanding of alien plant species on Sub-Antarctic Islands

Christien Steyn<fnref n="1" />, Peter le Roux<fnref n="1" />, Steven Chown<fnref n="2" />, Mark van Kleunen<fnref n="3" />, Wayne Dawson<fnref n="3" />, Marten Winter<fnref n="4" />, Franz Essl<fnref n="5" />, Jan Pergl<fnref n="6" />, Petr Pyšek<fnref n="6" />, <fnref n="7" />, <fnref n="8" />, Holger Kreft<fnref n="9" />, Patrick Weigelt<fnref n="9" />, Michelle Greve<fnref n="1" />

As alien species continue to spread across the globe, they increasingly threaten native biodiversity. In isolated island systems, especially on those where native species diversity tends to be low, alien invasions particularly pose a risk to native species. With human assistance aliens are even reaching climatically harsh environments, invading higher altitudes and higher latitudes. The Sub-Antarctic Islands (SAIs) are little influenced by human development and disturbance; however, humans remain responsible for substantial amounts of propagules reaching these areas. This has led to over 300 alien plants establishing across the 21 SAIs, of which 28 have been reported to be invasive on single or multiple islands. To mitigate future invasions, understanding and predicting the potential of aliens becoming invasive in the Sub-Antarctic is thus essential.

Here we use a climate matching approach to predict which plant invaders around the globe have the potential to establish on the SAIs if they were to reach the islands. We obtained a list of over 13000 plant species, which have become naturalized or invasive somewhere in the world, from GloNAF and the Global Invasive Species Database. Occurrence data for all species were extracted from GBIF and a species distribution modelling approach (BIOCLIM) used to establish whether the climate envelope of the alien species overlaps with the climatic conditions of the SAIs. We were able to identify 19 species that pose a potential high risk if introduced. Although climate matching is an important and cost-effective precursor to prevent alien species establishment, it is still not enough to fully understand invasion potential in the Sub-Antarctic. We thus also took a comparative trait-based approach, identifying the key characteristics that differentiate successful invaders from non-invasive aliens. The comparisons were performed by grouping species currently on the island with those species modelled to have a high, medium and low probability of occurring on the SAIs. This is a novel approach for the Sub-Antarctic and will benefit the research community working towards a better understanding of the biogeography and functional characteristics of successful alien species.

Keywords: Biogeography, Distribution Modelling, Functional traits, Invasion potential, Island invasions, Plant invasions, Sub-Antarctic Islands

<footnote n="1">¹School of Plant Sciences, University of Pretoria, Private Bag X20, Pretoria 0002, South Africa</footnote>

<footnote n="2">²School of Biological Sciences, Monash University, Victoria 3800, Australia</footnote>

<footnote n="3">³Ecology, Department of Biology, University of Konstanz, D-78464 Konstanz, Germany</footnote>

<footnote n="4">⁴German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, 04103 Leipzig, Germany</footnote>

<footnote n="5">⁵Division of Conservation, Vegetation, and Landscape Ecology, University of Vienna, 1030 Vienna, Austria</footnote>

<footnote n="6">⁶Department of Invasion Ecology, Institute of Botany, The Czech Academy of Sciences, CZ-252 43 Pruhonice, Czech Republic</footnote>

<footnote n="7">⁷Department of Ecology, Faculty of Science, Charles University in Prague, CZ-128 44 Prague, Czech Republic</footnote>

<footnote n="8">⁸Centre for Invasion Biology, Department of Botany & Zoology, Stellenbosch University, Matieland 7602, South Africa</footnote>

<footnote n="9">⁹Biodiversity, Macroecology & Conservation Biogeography, University of Göttingen, Büsgenweg 1, D-37077 Göttingen, Germany</footnote>
**Mechanisms of exploitation and interference competition in a novel invader – the
marbled crayfish**

Stefan Linzmaier<fnref n="1" />, <fnref n="2" />, <fnref n="3" />, Jonathan Jeschke<fnref n="1" />, <fnref n="2" />, <fnref n="3" />

The capability to adapt to new or novel resources is key for the success of introduced species. In particular, differences in foraging parameters between resident and introduced predators can determine the establishment success of introduced predators and their effects on the resident community. We investigate such differences, thereby also looking at the link between predator functional responses and behavioural traits, which is largely unexplored. As model organisms, we focus on freshwater crayfish which had major impacts on recipient ecosystems worldwide. The marbled crayfish (*Procambarus fallax* forma *virginalis*) is a potentially upcoming invader and reproduces parthenogenetically, which is unique for decapod crustaceans. We compared marbled crayfish in a quantitative trait analysis with a species-archetype that is already present in many communities and exhibits comparable traits and a similar ecology: the spiny-cheek crayfish (*Orconectes limmosus*). We predicted interaction outcomes and derived expected community changes by comparing behavioural traits and functional responses of these two species. We investigated which predation parameters between the two species differ, how individuals differ in these parameters, and whether the parameters are connected to their functional response. To examine how behaviour mediates the interaction between two species and how individual behaviour and eco-evolutionary experience influence foraging behaviour, we quantified traits that determine key interspecific interactions (e.g. aggressiveness) underlying the invasion success of non-indigenous crayfish. These results were related to the individual functional responses to fathom the relationship between behaviour, predation parameters and the functional response.

Keywords: functional response, behavioral type, personality, competition, community
ecology, invasive crayfish

<footnote n="1">¹Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB), Berlin, Germany</footnote>

<footnote n="2">²Freie Universität Berlin, Department of Biology, Chemistry, Pharmacy, Institute of Biology, Berlin,
Germany</footnote>

<footnote n="3">³Berlin-Brandenburg Institute of Advanced Biodiversity Research (BBIB), Berlin, Germany</footnote>
# How life history influences invasiveness across terrestrial vertebrate classes

William Allen<fnref n="1" />,<fnref n="2" />, Sally Street<fnref n="2" />, Isabella Capellini<fnref n="2" />

Competing theoretical models of how life history influences population growth disagree on whether species with fast or slow life history traits should be advantaged in biological invasions. Species with a fast life history strategy may have an advantage because they can rapidly increase in numbers, limiting the period of increased vulnerability to stochastic events. Alternatively, species that employ a slow strategy may generally be more successful because their populations have reduced variance in vital rates in response to stochastic events. We test these competing predictions using global-scale comparative analyses of hundreds of species of mammals, reptiles and amphibians. Outcomes are tracked throughout the invasion pathway from introduction through establishment and spread. Using the largest database of life history traits yet assembled, invasion success or failure at each stage is associated with multiple life history traits to determine exactly how life history promotes invasiveness. We find that, in addition to dramatic biases in the life history traits of species humans introduce, there is a clear advantage for species with fast life history traits to establish and spread in amphibians, reptiles and mammals. This supports models that emphasize the importance of potential for rapid population growth in favourable conditions. Results contrast with studies of birds, where instead division of reproductive effort into many attempts seems to be key. We suggest that this difference can be attributable to birds' relatively long reproductive lifespans, creating potential for alternative population survival and growth strategies such as bet-hedging, storage and buffering. Results could be used to screen new introductions for species with life histories that have the highest invasion potential.

Keywords: life history traits, invasiveness, amphibians, reptiles, mammals, species prioritization, comparative methods, introduction biases

<footnote n="1">¹Swansea University, Swansea, United Kingdom</footnote>

<footnote n="2">²University of Hull, Hull, United Kingdom</footnote>
Session 3

Ecological impacts of biological invasions

We-S3-03

**Alien species classification and missing data: impact matters**

Sabrina Kumschick

*Centre for Invasion Biology, Department of Botany and Zoology, Stellenbosch University, Matieland, South Africa*

*Invasive Species Programme, South African National Biodiversity Institute, Claremont, South Africa*

Alien species can cause a broad range of changes to the recipient environments. Classifying alien species according to the magnitude of impact caused can inform management decisions and aid the protection of native biodiversity. A generic impact scoring system which enables to compare highly diverse impact metrics between taxa has been developed for this purpose. It includes impacts caused through various mechanisms, ranging in intensity from Minimal to Massive depending on the level of organization affected in the recipient environment (individuals, populations, communities, ecosystems). The classification of aliens according to this system relies on primary impact data collected on the focal species in the field. We reviewed different strategies, including specific experimental approaches and observational methods, for detecting and quantifying the ecological impacts of alien species. Our synthesis points out that different experimental methodologies are appropriate for different taxa due to particular properties of the species and ecosystems involved, even though most methods are theoretically possible for most organismal groups. Our recommendations to conduct experiments on impact include a four-way-plot experimental design (uninvaded, invaded, removal of natives, removal of aliens) – not only to reveal ecological and potentially irreversible impacts, but also to determine the potential success of restoration efforts. Furthermore, we identify hypothesis-driven parameters that should be measured at invaded sites to maximize insights into the nature of impact. Our recommendations aim at providing a basis for developing systematic quantitative measurements to allow comparisons of impact across alien species, sites and time, and to maximize the usefulness and outcomes of impact studies, also with regards to a generic classification system for alien species.

Keywords: Impact assessment, risk, management, Environmental Impact Classification of Alien Taxa
**Multiple impacts caused by the invasive tree Robinia pseudoacacia: insights from soil chemical features to microarthropods, nematodes, microbial and plant communities.**

Lorenzo Lazzaro<fnref n="1" />, Giuseppe Mazza<fnref n="2" />, Lorenzo Lastrucci<fnref n="1" />, Claudia Giuliani<fnref n="3" />, Alessandra Lagomarsino<fnref n="2" />, Silvia Landi<fnref n="2" />, Giada D'Errico<fnref n="4" />, Elena Tricarico<fnref n="5" />, Roberta Pastorelli<fnref n="2" />, Alberto Inghilesi<fnref n="5" />, Giulia Torrini<fnref n="2" />, Pio Roversi<fnref n="2" />, Arturo Fabiani<fnref n="2" />, Bruno Foggi<fnref n="1" />

The Black Locust *Robinia pseudoacacia* (BL) is a nitrogen-fixing tree belonging to the family *Fabaceae*. It is nowadays widespread and naturalized in Europe, temperate Asia, Australia, New Zealand, northern and southern Africa and temperate South America. This plant is an aggressive invader often spreading and replacing native forest formations in the invaded areas. Its ecological impacts are well-known, spanning from the decrease in native species richness and the functional shift of the invaded communities to the biotic homogenization of the understory vegetation and lichen communities. The effects of BL on native communities are mainly caused by an increase in nutrients availability associated with the nitrification of invaded soils. However, the studies on the effects of BL are often focused on few response variables, while more composite approaches, assessing the effects of the invasive plants on several response variables, are required. In particular, studies evaluating the impacts on the soil fauna and microbes are urgently demanded, given their importance in the invasion development and restoration process. The present study evaluates the impacts on soil chemical properties, soil microbial, nematodes, microarthropods and understory plant communities after the invasion of BL in a Central Italy in a comparison between uninvaded and invaded stands. To this end, soil and vegetation samplings were performed in stands invaded by *R. pseudoacacia* and native stands, represented by deciduous oak forests. As expected we detected qualitative and quantitative changes in all the components we analyzed, starting from the well-known soil nitrification and increase in soil nutrients, linked also to the soils acidification. In the invaded stands, species richness and abundance were found to be lower for plant communities, microarthropods and nematodes, while we detected an increase of richness for bacterial communities. In addition, a crucial functional shift was detected particularly for plants and for microarthropods communities. The index of Biological Quality of Soil indicates that microarthropods communities in invaded stands are poorer and less structured than those in native ones. All these data

confirm that BL transforms several components of the invaded ecosystems, modifying the plant-soil community and affecting biodiversity at several levels.

**Figure Caption.** PCA ordination diagram of sample plots and biotic and abiotic indexes varying significantly across invasion status. QBS = index of Biological Quality of Soil based on microarthropods community.

Keywords: QBS, species richness, species abundance, nitrification, alien

<figure><img src="image_10.png" /></figure>

<footnote n="1">¹Department of Biology, University of Florence, via G. La Pira 4, I-50121, Florence, Italy</footnote>

<footnote n="2">²CREA-ABP, Council for Agricultural Research and Economics, Research Centre for Agrobiology and Pedology, via di Lanciola 12/A, I-50125 Cascine del Riccio, Florence, Italy</footnote>

<footnote n="3">³Department of Pharmaceutical Sciences, University of Milan, via Mangiagalli 25, I-20133, Milan, Italy</footnote>

<footnote n="4">⁴Department of Agricultural Sciences, University of Naples Federico II, via Università 100, 80055, Portici, Italy</footnote>

<footnote n="5">⁵Department of Biology, University of Florence, via Romana 17, I-50125, Florence, Italy</footnote>
# Interacting invasive herbivores on hemlock: Effects on chemistry, growth and phenology

Colin Orians<fnref n="1" />, Robert Schaeffer<fnref n="1" />, Wilson Claire<fnref n="2" />, Mauri Barrett<fnref n="3" />, Carol Thornber<fnref n="2" />, Evan Preisser<fnref n="2" />

## Introduction:

Eastern Hemlock, *Tsuga canadensis*, is a shade-tolerant foundational tree species in eastern North America that is attacked by two invasive insects: hemlock woolly adelgid (HWA, *Adelges tsugae*) and elongate hemlock scale (EHS, *Fiorinia externa*). HWA, with minimal infestation, can reduce growth in a matter of weeks and, as densities increase, cause mortality in just 4 years. EHS's impact is more benign and can potentially ameliorate the effects of HWA when both co-infest the same host. Here, we show that the two species differ in their effects on hemlock chemistry and growth, and present new evidence that the two species have dramatically different effects on spring new flush initiation (leaf-out) and production. This has large implications for the long-term health of understory saplings that rely on early spring carbon fixation for maintenance and for the production of new growth each.

## Methods/results:

Hemlock saplings were planted in the field under a deciduous forest canopy, infested with HWA, EHS, or neither insect, and harvested after four years. Needles from HWA-infested trees had higher nitrogen, a pattern consistent with nutrient manipulation by the insect. HWA also affected traits associated with carbon gain. Rates of photosynthesis were lower, HWA-infested trees had ~15% less biomass aboveground, and the needle to ratio was ~20% lower than in control trees. The reduction in needles appears to be due to both reduced growth and premature needle loss. In addition, the production of new flush foliage in HWA-infested trees was delayed and one-third that of control trees, suggesting that HWA infestation limits the ability of hemlocks to maximize early spring carbon gain prior to hardwood leaf-out. In contrast, EHS-infested trees showed little difference in chemistry, leaf production or in the timing of bud break and production of new-flush foliage.

## Conclusion:

Adelgid-induced delays in bud break and decreases in new foliage production, in concert with the accelerated bud break of co-occurring hardwoods due to climate warming, may threaten early-spring and future resource gain in hemlocks. Since EHS has virtually no impact, our previous work showing that EHS deters HWA, suggests that the presence of EHS may be critical to the trees long-term survival in eastern North America.

Keywords: hemlock, understory, sapling, invasive insect, direct effects,

<footnote n="1">¹Tufts University, Medford, United States</footnote>

<footnote n="2">²University of Rhode Island, Kingston, United States</footnote>

<footnote n="3">³USDA-APHIS, Buzzards Bay, United States</footnote>
# The Eurasian (Castor fiber L.) and Canadian (Castor canadensis Kuhl) beavers in the European part of Russia: long-term population dynamics and interrelationships between the species

Varos Petrosyan<fnref n="1" />, Victor Golubkov<fnref n="2" />, Nikolai Zavyalov<fnref n="3" />, Zoya Goryainova<fnref n="1" />, Natalia Dergunova<fnref n="1" />, Andrey Omelchenko<fnref n="1" />, Sergey Bessonov<fnref n="1" />, Sergey Albov<fnref n="4" />, Natalia Marchenko<fnref n="5" />, Lyudmila Khlyap<fnref n="1" />, Yuri Dgebuadze<fnref n="1" />

The results of population dynamics analysis for two beaver species are presented with the help of two different models. The first model (one-species) is designed for population dynamics analysis of Eurasian beaver (Castor fiber L.) after its reintroduction into Laplandskiy, Darvinskiy, Central-Forest, Prioksko-Terrasnyi, Okskiy and Khoperskiy reserves, located in the northern, southern and central parts of the species range in European Russia. An analysis of the effectiveness of a discrete-time species-habitat relationship model (active, potential, degraded habitats) was provided for the quantitative description of the population dynamics in optimal, suboptimal and pessimal beaver habitats by the use of long-term monitoring data for the years 1934-2015. It has been demonstrated that population dynamics of Eurasian beaver could be described with the use of 4 types of models: irruptive (Laplandskiy Reserve); single-stage with a quasi-periodic oscillation (Prioksko-Terrasnyi Reserve), two-stage with quasi-periodic oscillations (Darvinskiy, Central-Forest, and Khoperskiy reserves) and logistic trend of the population number change with the periodic oscillations around it (Okskiy Reserve).

Canadian beaver (Castor Canadensis Kuhl) invaded Karelia and Leningrad Oblast of Russia in the early 1950s (Danilov et al., 2007). In recent years, Canadian beaver has invaded Arkhangelsk Oblast, the places previously inhabited by Eurasian beaver. At the same time, the replacement of Canadian beaver by Eurasian beaver in southern Karelia has been observed (Danilov et al., 2015). However, to date the nature of this replacement has been unclear. We hypothesize that between similar species could be a competition for habitat and food resources. We created the second discrete-time model (two species) in order to predict population dynamics for two species when both species use the same food resources. The estimates of the model indicate the replacement of Eurasian beaver by Canadian one for the territories of all studied reserves. However, the duration of this process depends on the initial population number of two species and their fertility characteristics, and varies from 75 to 150 years for different environmental conditions.

Data collection on the territory of the reserves was supported by RFBR grants 15-04-06423, 15-29-02550; mathematical models of population dynamics were developed with financial support of Russian Science Foundation grant № 16-14-10323.

Keywords: alien species, Castor fiber, Castor canadensis, mathematical model, competition, competitive exclusion, invasion

<footnote n="1">¹A.N. Severtsov Institute of Ecology and Evolution of the Russian Academy of Sciences, Moscow, Russia</footnote>

<footnote n="2">²Federal Research Centre "Information and Management" of the Russian Academy of Sciences, Moscow, Russia</footnote>

<footnote n="3">³Rdeysky Nature Reserve, Novgorod oblast, Russia</footnote>

<footnote n="4">⁴Prioksko-Terrasny Nature Biosphere Reserve, Moscow oblast, Russia</footnote>

<footnote n="5">⁵Khoperskiy Nature Reserve, Voronezh oblast, Russia</footnote>
Since the first feral populations of the harlequin ladybird, *Harmonia axyridis*, were found around the year 2000 in Germany and Belgium, it became one the most studied invasive alien species in Europe. From the beginning, and based on earlier observations on its invasion in North America, it was considered as a potentially very serious invader, for various reasons. First, it is a human nuisance that aggregates in very high numbers in buildings for overwintering. Secondly, it also aggregates on fruits in autumn and can taint wine when harvested and crushed with grapes. However, it was its potential ecological impact on prey and other aphidophagous predators that raised the most alarming concerns. Hundreds of native species were potentially endangered. Indeed, in the first years of its invasion, it rapidly spread to most European countries and alerted the general public because of its aggregation habits. It was also found preying on a large number of aphidophagous species, mainly ladybirds, and several studies indicated that indigenous ladybird species were declining. However, less than 20 years after the beginning of the invasion, people have become used to have ladybirds visiting their home every autumn, the beetle has never tainted any wine in Europe and, more important, recent studies suggest that only one indigenous species, *Adalia bipunctata*, has strongly declined (but remains rather abundant in some habitats). Similar observations are presently being made in North America. So, have we been too alarmist? Why has this species attracted so much concern compared to other invasive species that are economically and ecologically much more important? The presentation will also discuss the danger of over-emphasizing the impact of flagship invasive species, without forgetting to mention that *H. axyridis* provided a wonderful model species for studying insect invasion biology and ecology, fostering the discipline in Europe and being the inspiration for global collaborations at various scales.

Keywords: Harmonia axyridis, ecological impact, invasive ladybirds
Keynote 2 - Biogeography and macroecology of invasions

Th-K-02

# Pretty, hot and sometimes successful: naturalization potential of ornamental garden plants in a changing climate

Mark van Kleunen

Ecology, Department of Biology, University of Konstanz, Universitätsstrasse 10, 78464 Konstanz, Germany, Konstanz, Germany

Over 13,000 vascular plant species have become naturalized somewhere in the world. With over 46,000 species grown as ornamentals in private gardens and over 150,000 species in botanical gardens around the globe, ornamental horticulture is the major introduction pathway of alien plants. Indeed, more than 50% of the global naturalized flora is known to be grown in private gardens, and more than 90% of the global naturalized flora is grown in botanical gardens. Although this does not necessarily mean that these gardens are the actual sources of these naturalized species, it nevertheless indicates that gardens are a huge potential source for naturalized and invasive plant species. Ornamental garden plants, therefore require more attention in invasion biology.

Ornamental garden plants provide a unique system to study the potential drivers of plant naturalization and invasion for several reasons. First, for some regions, we have through the works of historian's information on the year of introduction, as well as proxies of planting frequencies for many ornamental plant species. Second, for many ornamental garden plants, we have information on their traits from garden-plant encyclopedia. Third, as many ornamental garden species have not managed to naturalize, at least not yet, we have data on non-naturalized introduced aliens to which we can compare the naturalized ones.

In this presentation, I will report on some of the recent studies from my lab and collaborators on determinants of the naturalization success of ornamental garden plants. As expected, we could show that time since introduction into gardens and planting frequency are positively related to current naturalization success. Despite recent reports of changes in climatic niches of invasive species, we showed that climatic suitability is another important driver of naturalization success. With regard to species traits, we found fewer consistent relationships with naturalization success. However, we found evidence for interactions between different traits and between traits and climatic suitability on naturalization success, thereby providing empirical evidence for the frequently claimed context dependency of traits. Moreover, using path analysis, we could show that certain frequently observed associations between species traits and naturalization success might reflect an introduction bias. In other words, we found that species with certain traits were introduced earlier and more frequently than others, and that this earlier introduction and high planting frequency promoted naturalization.

The strong effect of introduction history on naturalization success implies that with time, and possible changes in planting frequencies, many of the currently non-naturalized ornamental species pose a naturalization debt. Furthermore, given the strong association between climatic suitability and naturalization success, we might expect that with ongoing climate change, a new generation of naturalized species will emerge from our gardens. Therefore, I will finish my presentation with the first results of our BiodivERsA project WhoIsNext, in which we address
with modelling and experimental studies which ornamental garden species might be the invaders of the future.

Keywords: invasive alien species, horticulture, ornamental garden plants, naturalization, climate change

Thursday, 15 September 2016 - 09:45 - 10:30

Session 4 - Biogeography and macroecology of invasions

Th-S4-01

Scaling up from local climate matching in gardens to continental naturalization success: the case of ornamental woody plants in Europe

Noëlie Maurel, Mark van Kleunen

University of Konstanz, Konstanz, Germany

The ornamental pathway supplies considerable numbers of alien plant species, of which many escape from cultivation and establish self-sustaining populations in the wild (i.e. they naturalize). The geography of cultivation (i.e. which species are grown where) may depend on species traits in the first place. In particular, the local pool of species cultivated in a given garden may be restricted to those that are climatically suited (hardy enough) locally. To which extent this is true, and whether this ultimately affects the chance for a species to naturalize in the larger region, has thus far been largely overlooked. To test this hypothesis, we took advantage of a large dataset of ~1500 ornamental woody plant species grown in ~200 gardens s.l. (botanic gardens, parks and arboreta) across Europe, where the status of reproduction has been reported for each species in each garden. We compiled these data with information about the native range of the species, their growth form and winter hardiness, as well as their year of introduction to Europe and planting frequency. We first assessed the drivers of local reproductive success (fruiting yes/no). We then tested whether local reproductive success could mediate the effects of species traits and introduction history on naturalization success in Europe. We found that local matching between species winter hardiness and garden climatic conditions was associated with a higher probability of fruiting. Furthermore, we found that naturalization success in Europe was positively associated with the proportion of European gardens where a species successfully reproduced. Together, our results suggest that local climate matching in gardens promotes local reproductive success, which in turn contributes to continental naturalization success.

Keywords: hardiness, traits, introduction history, reproductive success, establishment, indirect effects
# Long-term dynamics of plant invasions: the role of residence time in determining invader performance

Christine Sheppard

University of Hohenheim, Stuttgart, Germany

Biological invasions are a major threat to biodiversity, but also pose useful natural experiments with the potential to provide many ecological and evolutionary insights. Aiming to explain causes of invasions, much research effort has focused on investigating differences between native and invaded ranges or between the two distinct groups of native and alien species. In contrast, temporal dynamics such as the potential effects of eco-evolutionary changes during the invasion process have received far less attention. However, new insights might be gained by comparing the dynamics of species and populations that differ in residence time and face different biotic and abiotic dissimilarities compared to their native range. This study investigated differences in invasion dynamics using Asteraceae species in Germany along an alien-native species continuum, which includes species of continuously increasing residence time (from recent neophyte over archaeophyte to native species). To investigate how residence time determines the performance and impacts of these plant species, a multi-species small-scale common garden experiment was combined with a large-scale macroecological analysis. In the experimental approach, small-scale establishment success in a native resident grassland community among 35 annual Asteraceae species with varying residence times was determined. From the macroecological perspective, a large-scale analysis of all Asteraceae species occurring in Germany illustrated how range sizes are influenced by residence time. At both scales, nonlinear patterns between plant performance and residence time were found, highlighting the importance of temporal dynamics. By contributing to a better understanding of the dynamic nature of biological invasions this study assists in explaining invasion mechanisms and determining appropriate management responses. Moreover, investigating temporal dynamics of invasions and associated changing biotic interactions among invaders and resident species will give insights to fundamental ecological and evolutionary processes in general.

Keywords: plant invasion, temporal dynamics, residence time, rapid evolution, biotic interaction, experiment, macroecology, alien-native continuum
# Newspaper Stars in Feathers – reconstruction of passerine invasion history in New Zealand

Pavel Pipek<fnref n="1" />, <fnref n="2" />, Petr Pyšek<fnref n="1" />, <fnref n="2" />, <fnref n="3" />, Tim Blackburn<fnref n="4" />

Bird introductions to New Zealand are a model system for macroecological analyses of invasiveness because the introductions of birds were deliberate, organized, and the Acclimatization Societies responsible for the majority of introductions kept good records. However, the propagule pressure data used for these analyses have recently been criticized, and indeed the data on which these studies are based have been subject to errors and misinterpretations. Recently, we published a case study of the history of Yellowhammer (Aves: Emberiza citrinella) introductions to New Zealand (Pipek et al. 2015) to show that such errors and misinterpretations can be corrected when all available documents (including newspaper articles) are utilized. In this paper, we extend the Yellowhammer case study to all passerine species imported to New Zealand, with the aim of producing robust and accurate data on the pathways and numbers of birds shipped to and liberated there in the second half of the 19th century. In total, we identified 129 records of ships carrying birds to New Zealand (mostly from Great Britain and Australia), from 35 of which we have information about shipping mortality (both the number of birds loaded and surviving). The data show that some species were liberated earlier than has generally been appreciated, even before the first Acclimatization Societies were founded. Some species were being translocated from one part of New Zealand to other (often in their hundreds), instead of being imported directly from Great Britain. Overall, therefore, these preliminary results show that the history of alien passerine introductions is more complex than thought based on works of previous researchers. How this affects our understanding of the drivers of establishment success in this system will be the subject of future analysis.

Keywords: birds, invasions, New Zealand, propagule pressure

<footnote n="1">¹Department of Ecology, Faculty of Science, Charles University, Prague, Czech Republic</footnote>

<footnote n="2">²Institute of Botany, Czech Academy of Science, Pruhonice, Czech Republic</footnote>

<footnote n="3">³Centre for Invasion Biology, Department of Botany & Zoology, Stellenbosch University, Mtieland, South Africa</footnote>

<footnote n="4">⁴Centre for Biodiversity & Environment Research, London, United Kingdom</footnote>
# Macroecological patterns of Europe's 100 of the worst invasive species under current and future conditions

Belinda Gallardo<fnref n="1" />, Pablo González<fnref n="2" />, Wilfried Thuiller<fnref n="3" />, Petr Pyšek<fnref n="4" />, Montserrat Vilà<fnref n="2" />, Chriss Yesson<fnref n="5" />

Among over 14,000 non-native species currently present in Europe, experts highlighted 100 species with some of the 'worst' ecological and socio-economic impacts. Here, we investigate macroecological patterns in their distribution under current and future climate conditions.

Species Distribution Models (SDM) were used to calculate Europe's suitability for each of the invasive species investigated. Beyond climate, we included information on global accessibility to account for the close relationship between invasive species distribution and human transportation. We projected SDM onto 12 different future scenarios combining different circulation models, emission trends and time periods. Sensitivity tests were conducted to investigate, and whenever possible correct, the influence on models of: algorithm, strategy of pseudo-absence selection, maximum number of presence records, spatial autocorrelation, sampling bias, and extrapolation onto novel climates.

The accuracy of SDM ranged from 0.87 to 0.99 AUC (0.61-0.97 TSS), which can be considered excellent. Between 47 and 73% of Europe's some of the worst invasive species are predicted to expand their range of distribution, depending on the future scenario analysed. Further, 41 species consistently showed range expansions for at least 10 out of the 12 future scenarios evaluated, whereas 32 species showed consistent contractions. Spatially, the Continental, Atlantic and Mediterranean (in that order) biogeographic regions accumulated the highest current and projected richness of invasive species. The core distribution of invaders shifted on average 37±16 km per decade towards the north, and 17±22 km towards the east of Europe. This velocity is two to six times faster than previously reported for native communities using a similar methodology. Range expansion was greatest at global mean temperature increases of 3.5°C, well above the 2°C cap recently adopted by the international community in Paris.

The effects of climate change are complex, multi-layered and context-dependent, which make estimation of future changes particularly difficult. Yet, considering additional information on the species biological traits (movement ability, ecological generalization and reproductive strategy), dispersal capacity and niche conservatism, we conclude that invasive species are likely to track the predicted spatial changes in climate suitability. Our projections provide the best estimated trends of some of the worst invasive species in Europe's based on current knowledge.

Keywords: climate change, biological invasion, Paris Agreement, poleward shift, range expansion

<figure><img src="image_11.png" /></figure>

<footnote n="1">¹Pyrenean Institute of Ecology (IPE-CSIC), Zaragoza, Spain</footnote>

<footnote n="2">²Doñana Biological Station (EBD-CSIC), Sevilla, Spain</footnote>

<footnote n="3">³University Joseph Fourier, Laboratoire d'Ecologie Alpine (LECA), Grenoble, France</footnote>

<footnote n="4">⁴Czech Academy of Sciences, Institute of Botany, Pruhonice, Czech Republic</footnote>

<footnote n="5">⁵Institute of Zoology (IOZ-LZS), London, United Kingdom</footnote>
Session 5

**Biogeography and macroecology of invasions**

Topic continued from previous session

Th-S5-01

**The drivers of the level of plant invasions world-wide**

Franz Essl, Wayne Dawson, Holger Kreft, Petr Pyšek, Jan Pergl, Mark van Kleunen, Patrick Weigelt, Bernd Lenzner, Thomas Mang, Dietmar Moser, Stefan Dullinger, Marten Winter

University Vienna / Environment Agency Austria, Vienna, Austria

Biological invasions have become a defining feature of global environmental change. However, the factors that determine variation in the level of invasions world-wide are still poorly understood. Here, we present and analyze the level of plant invasions across invasion stages (i.e. the proportion of naturalized and invasive species relative to the native species numbers) in 849 regions world-wide.

We use the Global Naturalized Alien Flora (GloNAF) database, which has become the most comprehensive resource for alien plant species distributions (van Kleunen et al. 2015), as source for calculating naturalized and invasive plant species richness per region. We then analyze the level of invasions by naturalized and invasive plant species dependent on region variables by means of generalized linear mixed effects models. In this presentation, we will present key insights that have emerged from this analysis.

We show that highest absolute numbers of native plant species are found in tropical mainland regions, while naturalized species numbers peak in temperate to subtropical mainland regions. We find that highest numbers of invasive alien plant species are again reported for temperate to subtropical regions, but with a strong decline towards tropical regions. However, in relation to native species diversity the global level of plant invasions shows a remarkably different picture. Highest levels of naturalized plant species are found in tropical and subtropical islands across the globe, with 82 of all islands (26%) having accumulated more naturalized alien plant species than are native on the same island. This contrast in the level of invasion between islands and mainland regions is perpetuated for invasive alien species. Finally, we reveal how environmental and anthropogenic pressures and biogeographic context interact in driving the level of plant invasions, and how the relevance of these pressures changes across invasion stages.

**Reference**

van Kleunen M. et al. (2015). Global exchange and accumulation of non-native plants. Nature 525: 100–103.

Keywords: alien species, biogeography, distribution, macro-ecology
# Patterns and predictions of the global spread of alien species: The intermediate distance hypothesis

Hanno Seebens<fnref n="1" />, <fnref n="2" />, <fnref n="3" />, Franz Essl<fnref n="3" />, Bernd Blasius<fnref n="2" />

The global distribution of alien species is largely driven by human activities such as global trade, horticulture or tourism. For example, the number of alien species of a country has been shown to be highly related to the volume of imported commodities. However, the global spreading dynamics of alien species, e.g. the spread between continents, remain poorly understood although knowledge about their spread is crucial to understand the global distribution of alien species. Furthermore, although many studies analyzed the relationship between alien species numbers and imported commodities, the global flows of alien species have never been compared to the global flows of commodities. We will present a first analysis of the geographic distance between native and alien regions of alien species using distributional data of 1380 species from various taxonomic groups. We show that the number of alien species is roughly spoken a hump-shaped function of geographic distance between native and alien ranges with highest species numbers at intermediate global distances of around 10,000 km. In contrast, the volume of exchanged commodities is highest at short distances. Consequently, exchanged trade volume alone is a poor predictor of alien species spread. We solve this discrepancy to common expectations by formulating a simple model combining exchanged trade volume with a measure biogeographical dissimilarity of ecological communities. Despite its simplicity, the model can already explain a large amount of the observed variability. Formulated in the intermediate distance hypothesis, we state that trade volume is only a good predictor in conjunction with the consideration of the proportion of alien to native species at a given distance. The process of invasion is often very complex for single species, but here we show that the resulting global spreading patterns across taxa can already be explained by simple models.

Keywords: global spread, model, trade

<footnote n="1">¹Senckenberg Biodiversity and Climate Research Centre (BiK-F), Frankfurt, Germany</footnote>

<footnote n="2">²Institute for Chemistry and Biology of the Marine Environment, University of Oldenburg, Oldenburg, Germany</footnote>

<footnote n="3">³Division of Conservation, Landscape and Vegetation Ecology, University of Vienna, Vienna, Austria</footnote>
# Plant invasions in mountains: improving invasive species distribution models' performances by accounting for the road network

Jonas Lembrechts<fnref n="1" />, Jonathan Lenoir<fnref n="2" />, Nina Roth<fnref n="1" />, Tarek Hattab<fnref n="2" />, MIREN Consortium<fnref n="3" />, Ann Milbau<fnref n="4" />, <fnref n="5" />, Ivan Nijs<fnref n="1" />

Roads are known to act as corridors for the dispersal of non-native plant species into mountain ecosystems. Previous research has shown a strong correlation between mountain roads and the distribution of most non-native mountain invaders, with upward expanding ranges of non-native species in roadsides compared to their distribution in the surrounding vegetation. With their different microclimate, reoccurring disturbance events, altered biotic interactions and facilitation of species movement, roads show several characteristics that indeed improve the chances for range expansion of non-native species. We argue that the connection of most common global non-native species with the road network in mountains could be more determinant of their spatial distribution than their climatic niche, as most of them are climate generalists and able to cope with a wide range of climatic conditions. It is thus key to integrate roads into species distribution models (SDMs) of non-native plants in mountains, as it will greatly improve our ability to describe and predict the current and future distribution of mountain invaders. With an elegant dataset of the occurrence of non-native species along mountain roads in more than ten mountain regions all over the world (from MIREN, the Mountain Invasion Research Network: http://www.mountaininvasions.org), we show here how SDMs based on a combination of fine-grain (50 m x 50 m) climate and topographical data and accounting for “distance to the road” as an extra predictor variable greatly improves model performances. We highlight the important implications for the conservation of mountain environments in a warming climate.

Keywords: Disturbance, mountains, plant invasion, roads, SDMs

<footnote n="1">¹Centre of Excellence of Plant and Vegetation Ecology, University of Antwerp, Wilrijk, Belgium</footnote>

<footnote n="2">²UR "Ecologie et Dynamique des Systèmes Anthropisés" (EDYSAN, FRE 3498 CNRS-UPJV), Université de Picardie Jules Verne, Amiens, France</footnote>

<footnote n="3">³Institute of Integrative Biology (IBZ), ETH Zürich, Zürich, Switzerland</footnote>

<footnote n="4">⁴Climate Impacts Research Centre (CIRC), Department of Ecology and Environmental Science, Umea University, Abisko, Sweden</footnote>

<footnote n="5">⁵Research Institute for Nature and Forest INBO, Department of Biodiversity and Natural Environment, Brussels, Belgium</footnote>
Session 5
Invasive species and changes in landuse

Th-S5-04

Influential factors across an invasion process: the invasion of the Scotch broom in Nahuel Huapi National Park (Argentina)

Ana Montero-Castaño<fnref n="1" />, Carolina Morales<fnref n="2" />, Pablo González-Moreno<fnref n="1" />,<fnref n="3" />, Montserrat Vilà<fnref n="1" />, Marcelo Aizen<fnref n="2" />

Exotic species have to overcome a series of biotic and abiotic barriers in order to succeed and become invasive. Influential factors, either intrinsic of the exotic species or environmental, change their relative importance along the invasion process. For instance, factors determining the arrival of an exotic entomophilous plant to a new area might highly differ from those determining the availability of suitable pollinators, decisive for its reproduction and persistence.

<figure><img src="image_12.png" /></figure>

In this study, we built a theoretical causal model for the invasion process of entomophilous exotic plants (Figure).

Our objective was to complete this model with the most explicative factors, testing it through Structural Equation Models. For that purpose, we studied the invasion of the Scotch broom (Cytisus scoparius) in Nahuel Huapi National Park (Argentina); a very interesting study system for several reasons. First, C. scoparius exclusively depends on sexual

reproduction and is self-incompatible and alogamous. Besides, once its flowers are visited, they remain tripped, being the proportion of tripped flowers a good surrogate of visitation rate, allowing the estimation of visitation rate in a high number of populations without the need of conducting pollination censuses. Second, the study area is an ecotone between the steppe and the humid forest, allowing the exploration of wide environmental (climatic, topographic and land use) ranges. Along three transects with marked and non-correlated environmental gradients, we studied 107 populations of C. scoparius, in which we estimated its cover in 100m radius, as a proxy of its establishment; and visitation rate, as a proxy of its reproductive success. In addition, in each population we measured a total of 11 climatic, topographical and land use factors.

The propagule pressure was determined by urban cover at 100m radius, as this plant is used in gardens as ornamental. This pressure, together with the annual mean temperature, positively affected C. scoparius cover. Interestingly, the relationship between C. scoparius cover and visitation rate was negative. Finally, the availability of pollinators was determined by both urban and shrubland covers at 500m radius. Shrubland cover might provide suitable areas for pollinators. However, urban cover had a negative effect on the availability of pollinators and subsequent visitation rate, probably because there other ornamental species are simultaneously in bloom competing for pollinators with C. scoparius. We expect this approach to be a useful theoretical framework for other invaded systems.

Keywords: Cytisus scoparius, entomophilous alien plants, landscape scale

<footnote n="1">¹Estación Biológica de Doñana (EBD-CSIC), Sevilla, Spain</footnote>

<footnote n="2">²Laboratorio Ecotono, Universidad Nacional del Comahue-INIBIOMA (CONICET), San Carlos de Bariloche, Argentina</footnote>

<footnote n="3">³Centre for Agriculture and Biosciences International (CABI), Egham, United Kingdom</footnote>
# Patterns of plant invasions over 60 years in a developing forest

Chad Jones

Connecticut College, New London, United States

For many years, intact forests have been thought to resist invasion. However, recent evidence suggests that even undisturbed forests are susceptible to invasive plant species. This could either be because species are able to invade following disturbances and then persist (the window of opportunity pattern) or because they are shade tolerant and able to spread even in undisturbed conditions. Using a long term dataset, I examined the overall patterns in abundance and diversity of exotic and invasive species over time to determine the effects of forest development and maturation on invasion. I then explored environmental factors influencing the spread of six common invasive species at the study site. Data were collected in 890 3X3m plots every 10 years beginning in 1952 in a natural area in southeastern Connecticut, USA. In 1952 the study area consisted of a mix of old fields, shrub land and secondary forest, but forests have been allowed to develop and mature since then throughout the site.

Overall, the abundance of exotic species declined significantly in the first 20 years of forest development. However invasive exotic species increased across the 60 years, due largely to six species. Three of these increased dramatically over the first 30 years but have since leveled off – suggesting the window of opportunity pattern - while the other three invaded later and continued to increase. Across the study site, the youngest forests have been more heavily invaded, but this pattern has decreased over time with some of the species (particularly *Celastrus orbiculatus*) progressively moving into older forests. Tree basal area was not a strong predictor of invasions for any of the species, suggesting that they are not taking advantage of canopy gaps to spread. Invasion by these species was greater in areas with higher existing richness and closer to existing populations of the species. These results suggest that while undisturbed forests are likely to have fewer exotic species overall, forests will continue to be invaded by a subset of species, either taking advantage of windows of opportunity or through the spread of shade tolerant invasive species. Both patterns can operate simultaneously.

Keywords: temperate forest, shade-tolerance
**Keynote 3 - Non-native pests and pathogens**

Th-K-03

**Invasive Alien Species and Pathogens: interactions, impact and strategies for control**

Alison Dunn

Institute of Integrative and Comparative Biology, Faculty of Biological Sciences, University of Leeds,
Leeds, United Kingdom

Species distributions are changing at an ever-increasing rate as a result of human activity. Two key processes of redistribution - biological invasion and disease emergence - are often interlinked. Indeed, for nearly one quarter of the invasive alien species (IAS) in "100 of the world's worst" list, environmental impacts are linked to diseases of wildlife. Parasites (macroparasites, microparasites) are frequently implicated in altering the outcome or impact of invasions. Parasites may be left behind in the host's ancestral range, affording the host "enemy release", or they may be introduced into new communities along with invading species. I will use studies of freshwater ecosystems to illustrate how parasites can change the strength of interactions between invasive and native species.

Although IAS are a significant source of 'pathogen pollution' defined as the human-mediated introduction (often unintentional) of a pathogen to a new host or region, surprising little is known about the biology of alien pathogens and their biodiversity impacts after introduction into new regions. I discuss the outcome of a recent EU workshop which identified areas for research and action, including those relevant to the processes of introduction and establishment of an alien pathogen and to prediction of the spread and associated impact of an alien pathogen on native biota and ecosystems.

In contrast with international policy on emerging diseases of humans and managed species, global policy on invasive species and parasites of wildlife is fragmented and the lack of international cooperation encourages individual parties to minimise their input into control. I look at the parallels between the process of biological invasion and of disease emergence, and discuss how these threats can be countered, focusing on biosecurity.

Keywords: biological invasions, pathogens
Session 6
Non-native pests and pathogens

Th-S6-01

**Alien species of human health concern: Evidence syntheses for impacts and management effectiveness**

Stefan Schindler<fnref n="1" />,<fnref n="2" />, Helen Bayliss<fnref n="3" />, Mildren Adam<fnref n="1" />, Wolfgang Rabitsch<fnref n="1" />, Franz Essl<fnref n="1" />,<fnref n="2" />, Hans-Peter Hutter<fnref n="4" />, Peter Wallner<fnref n="4" />, Swen Follak<fnref n="5" />, Andrew Pullin<fnref n="3" />

Alien species are more and more recognized for having impacts detrimental to human health through injury, allergy, or as vectors of disease. Increasing international trade and climate change are likely to impact on spread, abundance, physiology or phenology of alien species, potentially altering their health impacts. Yet despite this topic receiving increasing attention in the scientific literature, there have been few attempts to quantify recent changes in human health impacts. We conduct different approaches of knowledge and evidence syntheses on this topic for Europe: First, we present findings from a systematic map of the literature identifying evidence of any change in the occurrence, frequency or severity of impacts of alien species on human health. Relevant studies related to only a few species, often report specific cases and rarely link health impacts with ecology, distribution or spread. Much of the available evidence represented first reports of illness or injury resulting from exposure to alien species. Five studies provide the first reports of autochthonous transmission of exotic diseases (two of Chikungunya virus and three of Dengue fever) by non-native mosquito species of the *Aedes* genus (*A. albopictus* and *A. aegypti*) established within Europe with up to more than 2000 humans affected. Evidence also suggests that harmful blooms of alien unicellular algae such as *Ostreopsis* species are causing significant health impacts along Mediterranean coasts. Other impacts arising from contact with alien animal species include dermatitis associated e.g. with contact with the oak processionary moth *Thaumetopoeia processionea*. Beside first reports of impacts, changes in sensitisation levels, e.g. to *Ambrosia artemisiifolia*, among the human population are reported. These studies indicate that levels of sensitisation are rising and the proportion of young people sensitised is increasing. Secondly, we conducted a systematic review to assess the effectiveness of management options used for common ragweed *Ambrosia artemisiifolia* and the effect of confounding factors such as habitat, climate and frequency and timing of the treatments. And thirdly, we developed a questionnaire on alien species and health impacts developed for Austrian stakeholders in environmental and health management to ask respondees about priority taxa, importance of expected direct health impacts (such as infections, allergies), and measures (environmental prevention, environmental control, medical prevention, medical therapy, etc.) to be recommended.

Keywords: health impacts, management effectiveness, evidence synthesis, knowledge synthesis, systematic map, systematic review, questionnaire

<footnote n="1">¹Environment Agency Austria, Department of Biodiversity and Nature Conservation, Vienna, Austria</footnote>

<footnote n="2">²University of Vienna, Division of Conservation Biology, Vegetation and Landscape Ecology, Vienna, Austria</footnote>

<footnote n="3">³Centre for Evidence-Based Conservation, School of the Environment, Natural Resources and Geography, Bangor, United Kingdom</footnote>

<footnote n="4">⁴Medical University Vienna, Centre for Public Health, Vienna, Austria</footnote>

<footnote n="5">⁵Austrian Agency for Health and Food Safety, Institute for Sustainable Plant Production, Vienna, Austria</footnote>
# Exploring the barriers to predicting alien pathogen invasions

Helen Roy

*Centre for Ecology & Hydrology, Wallingford, United Kingdom*

Over the last few decades there have been major advances in our understanding of biological invasions but very little is known about the biology of alien pathogens (defined as a disease-causing micro-parasite (an agent living in or on a host) that includes viruses, bacteria, fungi and fungus-like organisms) and their biodiversity impacts. Environmental impacts are linked to diseases of wildlife for one quarter of invasive alien species (IAS) listed as the “100 of the world’s worst”, but research and policy focus mainly has been on diseases of humans, vertebrate livestock and cultivated plant species. The spread of alien pathogens which affect wildlife has received considerably less attention.

Species inventories are recognised as critical for the management of biological invasions, informing horizon scanning and surveillance, and underpinning prevention, control and elimination of IAS. There have been major developments in the availability of high quality data on IAS which can be used to inform science, policy and ultimately conservation. However, very few include any alien pathogens and those that do so include only a few, notably, and not surprisingly, those with devastating effects on biodiversity such as *Aphanomyces astaci*, the causal agent of crayfish plague, and *Batrachochytrium dendrobatidis* and *B. salamandrivorans*, the chytrid fungi of amphibians. The threats posed by alien pathogens to endangered species, ecosystems, and ecosystem services should receive greater attention internationally through legislation, policy and management, both globally and locally. We explored the barriers to understanding alien pathogens, using expert consensus approaches through a workshop of the COST Action ALIEN Challenge, and identified key areas for research and action. Here I will describe the key findings and highlight the need for consideration of alien pathogens within an interdisciplinary approach to the health of people, domestic animals and wildlife.

**Keywords:** Invasive alien species, wildlife disease, legislation, One Health Initiatives, Microparasites
## Session 6
### Socioeconomic impacts of biological invasions

Th-S6-05

#### Plant pest impacts: A common set of metrics

Kylie Ireland<fnref n="1" />, <fnref n="2" />, Rieks van Klinken<fnref n="1" />, <fnref n="2" />, David Cook<fnref n="1" />, <fnref n="3" />, David Logan<fnref n="5" />, Lisa Jamieson<fnref n="5" />, Joy Tyson<fnref n="5" />, Philip Hulme<fnref n="1" />, <fnref n="6" />, Susan Worner<fnref n="1" />, <fnref n="6" />, Eckehard Brockerhoff<fnref n="7" />, <fnref n="8" />, John Fletcher<fnref n="5" />, Brendan Rodoni<fnref n="1" />, <fnref n="9" />, <fnref n="10" />, Gabrielle Vivian-Smith<fnref n="10" />, Rosa Crnov<fnref n="10" />, Mark Whattam<fnref n="11" />, Mandy Christopher<fnref n="1" />, <fnref n="12" />, Barbara Hall<fnref n="13" />, Rod Turner<fnref n="14" />, David Teulon<fnref n="1" />, <fnref n="5" />, <fnref n="8" />, Mike Hodda<fnref n="1" />, <fnref n="2" />, Dean Paini<fnref n="1" />, <fnref n="2" />

Agricultural stakeholders are in need of a common set of metrics to evaluate plant pests. While conceptual frameworks for defining and classifying pest impacts have been developed in the invasion biology literature, many of these are limited by a lack of criteria for socio-economic and trade impact outcomes, which are largely prevalent in plant production systems. Despite considerable efforts to define crop loss assessment, yield losses, economic injury levels and damage thresholds for plant production systems, a generalised methodology for classifying such losses and impacts has never been clearly articulated. A generalised and common framework for quantifying and comparing pest impacts would be an invaluable tool for all plant biosecurity stakeholders. Such a framework would allow transparency, flexibility (in development and application) and harmonisation of pest management and prioritisation across spatial scales and jurisdictions. We present here a plant pest impact classification system that articulates, defines and classifies the impacts of pest species (both alien and native; historical, current and potential) in plant production systems. Criteria were defined by magnitude of impact, with a focus on production specific metrics. Economic assessment parameters used to analyse plant biosecurity impacts, risk assessment guidance tools developed by the IPPC, discussions with pest risk assessment professionals and the structure and insight of recent environmental impact classification schemes were used to identify criteria. Twenty impact metric criteria were identified, assigned to four key metric types: economic, management, spatiotemporal and socio-political, and nested under key components of the invasion and impact process. Host crop value, market access, feasibility of management and reversibility are identified as disruptor metrics, likely to influence overall impact classification by at least an order of magnitude difference compared to other criteria. Measures of spatial distribution, yield and quality losses and management response were also identified. Utility of the metric system is explored through application to Australian and New Zealand plant pests. This system demonstrates the value of integrating plant protection science with invasion biology, to derive a comprehensive measure of pest impact in agroecosystems. We acknowledge the support of the Australian Government's Cooperative Research Centres Program. This work forms a part of the Plant Biosecurity CRC project 1109: Pathways and Risk Assessment Framework for High Impact Species.

Keywords: alien invasive species (AIS), biosecurity, consequences, crop loss assessment, exotic species, non-indigenous species (NIS), plant production, prioritisation, pest effects, quarantine

<footnote n="1">¹Plant Biosecurity Cooperative Research Centre, Canberra, Australia</footnote>

<footnote n="2">²CSIRO, Canberra, Australia</footnote>

<footnote n="3">³Department of Agriculture and Food Western Australia, Western Australia, Australia</footnote>

<footnote n="4">⁴School of Agricultural and Resource Economics, University of Western Australia, Perth, Australia</footnote>

<footnote n="5">⁵The New Zealand Institute for Plant & Food Research, Auckland & Lincoln, New Zealand</footnote>

<footnote n="6">⁶The Bio-Protection Research Centre, Lincoln University, Lincoln, New Zealand</footnote>

<footnote n="7">⁷Scion (New Zealand Forest Research Institute), Christchurch, New Zealand</footnote>

<footnote n="8">⁸B3, Better Border Biosecurity, Lincoln, New Zealand</footnote>

<footnote n="9">⁹AgriBio, La Trobe University, Bundoora, Australia</footnote>

<footnote n="10">¹⁰Department of Economic Development, Jobs, Transport and Resources, Victoria, Australia</footnote>

<footnote n="11">¹¹Department of Agriculture and Water Resources, Canberra, Australia</footnote>

<footnote n="12">¹²Department of Agriculture and Fisheries, Queensland, Australia</footnote>

<footnote n="13">¹³South Australian Research and Development Institute, South Australia, Australia</footnote>

<footnote n="14">¹⁴Plant Health Australia, Canberra, Australia</footnote>
Session 6

Restoration of invaded ecosystems

Th-S6-03

# Restoration of a blackberry-invaded unique forest in Galápagos: impacts on the vegetation, birds and invertebrates

Heinke Jäger<fnref n="1" />, Alonso Carrion<fnref n="2" />, Jacqueline Rodriguez<fnref n="1" />, Denisse Barrera<fnref n="1" />, Sabine Tebbich<fnref n="3" />, Arno Cimadom<fnref n="3" />, Christian Sevilla<fnref n="3" />, Charlotte Causton<fnref n="1" />

Understanding the interactions of introduced species with their novel environment is important for any ecological system. But where invasive species pose a threat to endangered species, it is especially important since it provides a holistic perspective of invader – ecosystem interactions. Blackberry (*Rubus niveus*) and other introduced species have invaded a unique forest on the Galapagos island of Santa Cruz dominated by the endemic tree *Scalesia pedunculata*, which is a critical habitat for Darwin’s finches. High cover of invasive *Rubus* has led to significantly lower native plant species richness and cover, as well as to changes in the *Scalesia* forest structure. The intense use of herbicides by the Galapagos National Park Directorate to control these invasive species may have led to direct and indirect changes in plant communities and the composition of invertebrate communities, which could negatively impact insectivorous birds.

Consequently, we initiated a community level study to determine the direct and indirect effects that the control of *Rubus* and other invasive species has on the plant, invertebrate and bird communities. This involved quantifying plant and invertebrate diversity and abundance in 34 plots (10×10 m) and the effects of habitat change on food availability. We also studied impacts on the breeding success (nests that produced at least on fledgling) of Darwin's finches.

Our data suggest that the control of invasive plant species led to lower invertebrate abundance as herbicide usage results in the temporary removal of the entire understory. Whether this resulted in a lower breeding success of the finches is not clear at this moment, since due to drought conditions in 2015, the overall breeding success was low. We expect clearer results from the current breeding season. After an initial drop in the density and cover of plant species after herbicide application, a dramatic recovery of native plant species and especially of *Scalesia pedunculata* ensued. Although there were no *Scalesia* seedlings in the heavily *Rubus*-invaded plots, over 300 seedlings occurred in some of them only 5 months after the last herbicide application. In addition, the natural regeneration of *Scalesia* and other native and endemic species equalled that of those planted after cultivation in the nursery, making cost- and labour-intensive restoration efforts unnecessary. These results suggest long term benefits of the restoration efforts of the *Scalesia* forest on Santa Cruz Island carried out by the Galapagos National Park Directorate.

Keywords: Rubus niveus, ecological restoration, invasive species control impacts, Darwin's finches

<footnote n="1">¹Charles Darwin Foundation, Galapagos, Ecuador</footnote>

<footnote n="2">²Galapagos National Park Directorate, Galapagos, Ecuador</footnote>

<footnote n="3">³University of Vienna, Vienna, Austria</footnote>
# Challenges to invasive alien plant control and ecosystem restoration in the Cape fynbos, South Africa

Jennifer Fill<fnref n="1" />, Brian van Wilgen<fnref n="1" />, Johan Baard<fnref n="2" />, Chad Cheney<fnref n="3" />, Aurelia Forsyth<fnref n="4" />, Greg Forsyth<fnref n="5" />,
Tineke Kraaij<fnref n="6" />, David Le Maitre<fnref n="5" />

Invasive alien plants are of widespread concern due to their severe impacts on the conservation
of South Africa's fynbos biome. Although a large amount of money is being spent on invasive
alien plant control in fynbos, there are concerns that current approaches are failing to reduce the
problem. To find effective solutions, it is necessary to accurately estimate the extent of the
problem and the effectiveness of current control operations. We investigated this issue at two
scales. First, we assessed the extent of invasion in fynbos protected areas, which experience
ongoing invasion by alien woody plants in the genera *Pinus*, *Hakea* and *Acacia*. We estimated
the resources and measures that would be required for their effective control. At a smaller scale,
we examined a long-term invasive alien plant clearing effort over the last thirteen years in a
mountain catchment within the fynbos biome. Our objectives were to assess the effectiveness
of control measures in this catchment over 13 years (2001-2014) and the degree of native
vegetation recovery. The catchment was historically planted with pines (by the 1940s),
primarily *P. pinaster* and *P. radiata*, two of the most invasive *Pinus* species in fynbos. Clearing
efforts were initiated in 2001 and have continued to the present. We compared vegetation
composition and cover between cleared areas that were previously plantations or invaded
natural vegetation, with a reference site (uninvaded fynbos). We evaluated the results in light
of patterns of landscape-scale resource allocation and invasive alien plant cover. We suggest
that current approaches to invasive alien plant control in fynbos should be rigorously re-
evaluated with respect to specific restoration objectives. Strategic management and allocation
of resources will be necessary to effectively achieve desired future conditions.

Keywords: biodiversity, Cape Floristic Region, conservation, invasion, management

<footnote n="1">¹Centre for Invasion Biology, Stellenbosch University, Matieland, South Africa</footnote>

<footnote n="2">²South African National Parks, Garden Route Scientific Services, Knysna, South Africa</footnote>

<footnote n="3">³South African National Parks, Table Mountain National Park, Constantia, South Africa</footnote>

<footnote n="4">⁴Cape Nature, Scientific Services, Stellenbosch, South Africa</footnote>

<footnote n="5">⁵Natural Resources and the Environment, Council for Scientific and Industrial Research, Stellenbosch,
South Africa</footnote>

<footnote n="6">⁶Nelson Mandela Metropolitan University, School of Natural Resource Management-Nature
Conservation, George, South Africa</footnote>
**Keynote 4 - Genetics and evolution of invasive species**

Fr-K-04

**Evolution of Osmoregulation Arising from Fluctuating Seas, and Implications for Invasions**

Carol E. Lee

*Center of Rapid Evolution (CORE), University of Wisconsin, Madison, United States*

An intriguing question remains as to why some groups show the evolutionary capacity to invade novel habitats, whereas most do not. In recent years, many species invading freshwater habitats have originated from more saline environments, disproportionate to their rate of transport. Identifying the specific genetic mechanisms that underlie physiological evolution during freshwater invasions might bring us closer to determining why particular populations have the capacity to cross this formidable boundary, and also provide general insights into why certain species have the ability to invade. The copepod *Eurytemora affinis* has invaded freshwater habitats multiple times independently from saline sources within the past century. Interestingly, some populations of *E. affinis* have the capacity to invade, whereas others do not. What properties characterize the invasive populations?

To dissect evolutionary responses during these independent habitat invasions, we integrated analyses of physiological function with comparative genomics. We analysed evolutionary shifts during invasions for pairs of ancestral saline source and derived freshwater populations across multiple independent invasions from genetically distinct clades. We found evolutionary shifts in function (ion uptake), as well as in expression of genes spanning many functional categories, including osmoregulation, energy production, and stress response. In many cases, there were striking parallel evolutionary shifts across independent invasions, particularly with respect to ion uptake activity and expression. The evolutionary parallelism we observed in this study might have relevance for taxonomically different but ecologically similar species that invade across similar habitat clines.

Physiological evolution during invasions appears to occur through natural selection acting on standing genetic variation in the native range. Balancing selection in the native range would be important for maintaining this genetic variation, enabling a population to become invasive. Consistent with this fact is the striking pattern that invasive populations appear to originate from habitats characterized by fluctuating conditions, which could lead to a form of balancing selection. In addition, we found experimentally that the copepod *E. affinis* exhibits reversal of dominance in salinity tolerance between saline and freshwater habitats (or marginal overdominance). The combination of fluctuating selection and marginal overdominance would greatly promote the maintenance of genetic variation in the native range, providing genetic substrate upon which selection could act during invasions. The tendency for fluctuating habitats to increase the evolutionary potential of populations might explain why so many invaders arise from the fluctuating habitats of the Ponto-Caspian Seas.

Keywords: ionic regulation, balancing selection, standing genetic variation, adaptation, physiology, genomics, Ponto-Caspian
Session 7 - Genetics and evolution of invasive species

Fr-S7-01

**Using genetic tools to inference expansion pattern of the raccoon dog**

Frank Drygala, Alain Frantz

Section de Zoologie, Musée national d'histoire naturelle 25, rue Münster L-2160 Luxembourg

The extent of gene flow during the range expansion of non-native species influences the amount of genetic diversity retained in expanding populations. We analyse the population genetic structure of the raccoon dog (Nyctereutes procyonoides) in north-eastern and central Europe. This invasive species is of management concern because it is highly susceptible to fox rabies and an important secondary host of the virus. We hypothesized that the large number of introduced animals and the species' dispersal capabilities led to high population connectivity and maintenance of genetic diversity throughout the invaded range.

We genotyped 332 tissue samples from seven European countries using 16 microsatellite loci. Different algorithms identified three genetic clusters corresponding to Finland, Denmark and a large 'central' population that reached from introduction areas in western Russia to northern Germany. Cluster assignments provided evidence of long-distance dispersal. The results of an Approximate Bayesian Computation analysis supported a scenario of equal effective population sizes among different pre-defined populations in the large central cluster.

Our results are in line with strong gene flow and secondary admixture between neighbouring demes leading to reduced genetic structuring, probably a result of its fairly rapid population expansion after introduction. The results presented here are remarkable in the sense that we identified a homogenous genetic cluster inhabiting an area stretching over more than 1500km. They are also relevant for disease management, as in the event of a significant rabies outbreak, there is a great risk of a rapid virus spread among raccoon dog populations.

Keywords: carnivore, genetic diversity, invasion genetics, invasive species, long-distance dispersal, population genetics
# Using population genetics to understand the evolutionary potential of an introduced parasitic nematode, the raccoon roundworm (*Baylisascaris procyonis*)

Natalia Osten-Sacken<fnref n="1" />, <fnref n="2" />, Mike Heddergott<fnref n="2" />, Martin Runge<fnref n="3" />, Alain Frantz<fnref n="2" />

Lebensmittel- und Veterinärinstitut Braunschweig/Hannover, Eintrachtweg 17, 30173, Hannover,
Germany

The raccoon roundworm (*Baylisascaris procyonis*) is a common gastrointestinal parasite of the raccoon (*Procyon lotor*), that is emerging as an important helminthic zoonosis. Translocations of raccoons have increased the global geographic range its roundworm as well. Raccoons are particularly abundant and wide-spread in Germany, where they can occur at high densities. Recent genetic work on the raccoon has provided evidence for at least four independent introduction events, which gave rise to genetically differentiated subpopulations in incipient contact of relatively high genetic diversity. The roundworm, however, does not occur in all raccoon populations and might therefore be much less genetically diverse due to reduced propagule pressure. In the present study, we aimed to establish how frequently the parasite was introduced into Western Europe and to examine the changes in genetic diversity during the invasion process. We collected *B. procyonis* from a total of 258 raccoons sampled in central Germany (Lower Saxony, Saxony Anhalt, Hesse). In our study sites, two raccoon founding populations, that both are subjected to *B. procyonis* infection, are in contact. We sequenced nuclear and mitochondrial markers, based on the mitochondrial genes cytochrome c oxidase 1 and 2 (CO1 and CO2) and the ribosomal ITS1, ITS2, 5.8S and 28S genes. We performed genotyping using 19 microsatellite markers. Our results provide evidence for a strongly reduced genetic diversity of the parasites introduced range. We will present and discuss our results relating to the number of independent introduction events.

Keywords: Raccoon roundworm, Baylisascaris procyonis, Raccoon, Procyon lotor, parasite, invasive species

<footnote n="1">¹Fondation Faune-Flore, 25 r. Münster, 2160, Luxembourg, Luxembourg</footnote>

<footnote n="2">²Musee National Histoire Naturelle, 25 r. Münster, 2160, Luxembourg, Luxembourg</footnote>

<footnote n="3">³Niedersächsisches Landesamt für Verbraucherschutz und Lebensmittelsicherheit (LAVES)</footnote>
# Exploring the invasion history of an exotic pest based on genetic markers: the case of the Asian long-horned beetle (Anoplophora glabripennis).

Marion Javal, Alain Roques, Géraldine Roux

INRA, UR0633 Zoologie forestière, Orléans, France

Insects are one of the most numerous groups of alien organisms introduced in Europe and as a result of globalization, the number of human-mediated introductions keeps growing. Among all the continents, Asia is so far considered as the region from which most of the newly-arrived alien species originate.

The Asian long-horned beetle (ALB) *Anoplophora glabripennis* is one of the insect species which benefited from international freight from Asia to Europe. It has been first detected in North America in 1996, then in Europe in 2003. This highly polyphagous species is able to infest a wide range of deciduous trees, especially in urban areas where its management results in significant economic costs.

In a context of recent European outbreaks (France 2013, Switzerland and Finland 2015), and in order to anticipate and to manage further ALB introductions, it is particularly important to uncover population's invasion routes as well as their pathways of dispersal in the invaded areas.

This work aims at evaluating the genetic structure of invasive populations in order to assess if the European outbreaks resulted from multiple independent introduction events or from the dispersal of a primary introduced population. We used sequences of mitochondrial COI gene as a preliminary approach. Our dataset covered most of the European outbreaks, some populations in North America and some in the native Asian range.

So far, the analysis of 36 populations from China and Korea revealed 23 haplotypes, with a very blurred geographic structure, probably resulting of an historic arrangement faded by potentially more recent population translocations, as hypothesized in previous studies. Only ten haplotypes were yet observed in Europe, three of them being shared with Asia and North America, five being private haplotypes and two being shared with Asia only. The genetic structure observed in Europe suggests a complex invasion scenario which likely includes several introduction events as well as dispersal within the invaded areas.

Keywords: invasive species, genetic structure, Asian Longhorned Beetle, Anoplophora, mitochondrial markers, insect
Session 8
Genetics and evolution of invasive species

Topic continued from previous session

Fr-S8-01

**Out of the Black Sea: Phylogeography of the invasive killer shrimp**
*Dikerogammarus villosus* across Europe

Tomasz Rewicz<fnref n="1" />, <fnref n="2" />, Remi Wattier<fnref n="3" />, Michał Grabowski<fnref n="2" />, Thierry Rigaud<fnref n="3" />, Tomasz Mamos<fnref n="2" />,
Karolina Bacela-Spychalska<fnref n="2" />

The killer shrimp, *Dikerogammarus villosus* (Crustacea Amphipoda), has been recognised as one of the 100 worst alien species in Europe, representing a major issue for local biodiversity and ecosystem functioning. During the last 20 years, it has colonized Central and Western Europe via the central and southern invasion corridors. Its spread was associated mainly with commercial shipping in large waterways but it was also transported overland to several Alpine Lakes and even overseas to the British Isles. This studies is an attempt to track the routes and dynamics of invasion of this one of the most effective freshwater invader. Molecular methods were used to reveal phylogeography of *D. villosus* in the native and invaded area as well as to tackle conservation issues. Through molecular studies we aimed to understand the dynamics of the species invasion in Europe. Our material consisted of 606 individuals sequenced for 16S and COI mitochondrial markers and 1228 individuals sequenced for seven microsatellite loci each from its entire European range including native and colonized area. In a result, four major populations in Danube, Dnieper, Dniester mouth and also Durngol Liman in Turkey were identified in the species native area. Two of them, from Dnieper and Danube mouth, were donors for independent routes of invasion along central and southern corridor. Microsatellite data allow to indicate Western Europe populations as a origin of latest introduction of *Dikerogammarus villosus* to UK and Alpine Lakes. Strong bottleneck effects may be seen in the populations from the isolated Alpine Lakes, showing that they come from a very low number of introduced individuals (showing high risk of overland transport). Such complex knowledge on the phylogeography of the killer shrimp may help to decrease risk of its future introductions to other areas, such as the North American Great Lakes and Balkan lakes.

Keywords: invasive species, dispersal, overland transport, demography, Ponto-Caspian, routes

<footnote n="1">¹Laboratory of Microscopic Imaging and Specialized Biological Techniques, University of Lodz, Lodz, Poland</footnote>

<footnote n="2">²Department of Invertebrate Zoology and Hydrobiology, University of Lodz, Lodz, Poland</footnote>

<footnote n="3">³Écologie-Évolution, UMR CNRS 6282 Biogéosciences, Université de Bourgogne, Dijon, France</footnote>
Never underestimate your opponent: adaptive phenotypic response in a recent
invader

Giovanni Vimercati, Sarah Davies, John Measey

Centre for Invasion Biology, Department of Botany & Zoology, Stellenbosch University, Stellenbosch,
South Africa

Invasive species frequently need to cope with ecological conditions that are dissimilar from
those they adapted to, presenting an opportunity to investigate how phenotype changes across
short time scales as a consequence of altered genotype-environment interaction. Furthermore,
phenotypic comparison between native and invaded ranges not only addresses basic eco-
evolutionary questions but also determines management actions helping e.g. to estimate species
invasion potential. The guttural toad *Sclerophrys gutturalis* is a generalist and synanthropic
species naturally distributed in tropical and subtropical central and southern Africa. It has
recently invaded a peri-urban area of Cape Town (CT) and despite a sustained extirpation
program the invasive range is still in expansion. The ability of the species to thrive and spread
across CT is surprising since the area is characterized by a Mediterranean climate that is
consistently drier and colder than that of the native range. Moreover, the introduction is very
recent, with the species first being detected in 2001. We measured the field hydration state of
guttural toads from the CT invasive population and a potential founder population from Durban.
We also obtained from laboratory trials: i) rates of evaporative water loss (EWL) and water
uptake (WU), ii) sensitivity of locomotor performance to hydration state, iii) critical thermal
minima (CTmins) and iv) interaction between CTmin and hydration state. In the field, hydration
levels of CT toads were significantly lower than in Durban toads. Although our lab experiments
showed that the two populations did not significantly differ in their rates of EWL and WU, the
effect of hydration state on locomotor performance varied substantially, with CT individuals
outperforming Durban individuals when dehydrated but not when fully hydrated. Also CTmin
was significantly lower in CT individuals than in Durban individuals. This difference remained
unaltered despite the hydration state of the toads. Thus, we found that the invasive population
shows in less than 20 years from the introduction an adaptive phenotypic response that may be
due to genetic adaption or phenotypic plasticity. Our results have management and conservation
implications because they show that the invasion potential of this species in CT is already higher
than we could infer from its native range.

Keywords: amphibian, anuran, biological invasion, physiology, hydration level, locomotion, evaporative water loss, water uptake, critical thermal minimum
**A multidisciplinary insight in *Robinia pseudoacacia* genetic and phenotypic diversity**

Cindy Verdu<fnref n="2" />, Xavier Bouteiller<fnref n="1" />, Emmi Aikio<fnref n="1" />, Kasso Daïnou<fnref n="2" />, Adline Delcamp<fnref n="1" />, Oliver de Thier<fnref n="2" />, Frédéric Gévaudant<fnref n="3" />, Erwan Giuchoux<fnref n="1" />, Yech'an Laizet<fnref n="1" />, Philippe Lejeune<fnref n="2" />, Coralie Mengal<fnref n="2" />, Samuel Quevauvillers<fnref n="2" />, Alexandre Raimbault<fnref n="1" />, Raphaël Ségura<fnref n="1" />, Ludivine Lassois<fnref n="2" />, Arnaud Monty<fnref n="2" />, Stéphanie Mariette<fnref n="1" />, Annabel Porté<fnref n="1" />

*Robinia pseudoacacia* is one of the 100 worst invasive species in Europe. In order to evaluate the mechanisms behind its invasiveness, we analysed the plasticity and genetic diversity of its populations, in a multidisciplinary approach. Molecular markers were developed to investigate the genetic structure and differentiation among populations. Comparative common gardens were set up to test for genetic differentiation and plasticity of phenotypic traits across the invaded range.

SNPs markers were developed from de novo RAD-seq assembly. Among 2020 RAD-loci, more than one third was identified as potential paralogous, and was filtered accordingly and 336 SNP were validated by genotyping as suitable markers. Populations from the USA (13), Belgium (10), Hungary (3) and Romania (2) were genotyped. Clones were detected with a maximum of 197m between two clones, indicating a high capacity of vegetative reproduction. A clear structure was observed between the native range and Europe. However, no structure was observed within Europe, suggesting an important and long-term gene flow between populations.

In parallel, 2000 seeds from 10 populations in Southern France and 10 populations in Belgium were sampled to set up a controlled experiment: seedlings were cultivated in two climatic chambers set at 18°C and 22°C, respectively (representative of Belgium and France spring temperatures). Germination and phenology of young seedlings were monitored, along with growth and photosynthetic traits. One individual per family was genotyped using SNP markers. Populations demonstrated a strong plasticity to temperature for all measured traits, the warmer environment being generally more suitable whatever the origin of the population. No genetic differentiation was evidenced using phenotypic traits and QST indexes; but the QST - FST comparison underlined a slight genetic differentiation at the molecular level. Overall, the genetic structure of these introduced populations demonstrated no local adaptation, but a high level of admixture with presence of some outlying populations.

The genetic differentiation between French and Belgian populations was not structured by range, and rather indicated the existence of particularities in some of the sampled populations. Results of the phylogeographic study in Belgium indicates a large genetic diversity and differentiation from native populations. Thus questions remain on the origin of the European populations, and the relative role of admixture, evolutionary processes and tree breeding in *R. pseudoacacia* introduction and invasion history.

Keywords: population diversity, temperature plasticity, molecular marker, invasive tree

<footnote n="1">¹Biogeco, INRA, Univ. Bordeaux, Cestas, France</footnote>

<footnote n="2">²Gembloux Agro-Bio Tech, Université de Liège, Gembloux, Belgium</footnote>

<footnote n="3">³BFP, INRA, Univ. Bordeaux, Villenave d'Ornon, France</footnote>
Fr-S8-04

**Public and expert perception of invasive neobiota and development of neobiota communication tools**

Xenia Junge<fnref n="1" />, <fnref n="2" />, Marcel Hunziker<fnref n="2" />, Nicole Bauer<fnref n="2" />, Arne Arnberger<fnref n="3" />, Roland Olschewski<fnref n="2" />, Daniel Fischer<fnref n="1" />

A crucial prerequisite for a successful prevention and management of invasive alien species (IAS) is the communication of the problems and threats of IAS in target groups as well as in the general public. To prevent new introductions and establishments, as well as a further spreading of IAS, the knowledge of the topic and of the respective species are of utmost importance. In addition, public critique can hinder measures to combat IAS, as some species might also provide aesthetic or economic benefits. To examine the awareness and knowledge of IAS, and preferences for six invasive neophytes and their management options in Switzerland, a representative Swiss-wide public survey was conducted. Complementary, the survey was conducted among Swiss neobiota experts to compare public and expert attitudes. In a next step, workshops were conducted by the responsible authority for neobiota of the Canton of Zurich to identify problems and gaps of the neobiota communication.

The public survey revealed that there is a rather weak knowledge of the topic as well as the problems related to IAS, whereas the species themselves are almost unknown. However, interventions to combat invasive neophytes are supported. Compared to the public, experts show a higher knowledge of the topic and the species and, to some extent, different management priorities. The workshops at the cantonal authority revealed a missing consensus among the different departments dealing with invasive neobiota. A consequence is an inconsistent communication to external stakeholders, which leads to misunderstandings and discrepancies. Further, the workshop revealed a lack of public discussion on the threats and damages related to IAS. To build a consensus in neobiota communication, about a dozen neobiota key messages were identified and formulated as communication guidelines in a participative process with all relevant departments.

Our findings provide useful insights for designing information campaigns and communication concepts to increase the knowledge of threats and problems of IAS in relevant target groups as well as in the general public. Thus, they can be helpful to develop successful IAS intervention and prevention strategies for a sustainable management of invasive neobiota considering both ecological and social factors. Further, it might be interesting to evaluate the effectiveness of the neobiota key messages after introducing them in communication tools.

Keywords: invasive neophytes, public survey, expert survey, communication concept, knowledge, acceptance, preferences, key messages, consistent communication

<footnote n="1">¹Office of Waste, Water, Energy and Air, Building Department Canton Zurich, Zurich, Switzerland</footnote>

<footnote n="2">²Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, Switzerland</footnote>

<footnote n="3">³Institute for Landscape Development, Recreation and Conservation Planning, University of Natural Resources and Life Sciences, Vienna, Austria</footnote>
**Smartphones: changing the way invasive species are reported**

Charles Bargeron, Keith Douce, Joseph LaForest, David Moorhead

University of Georgia, Tifton, United States

Smartphones have provided professionals with a tool for mapping invasive species that is as accessible to experts as to citizen scientists. Operational through the University of California Los Angeles) (UCLA) from 2008-2011, the What's Invasive application proved that reporting invasive species occurrences via a smartphone application was a viable option. University of Georgia - Center for Invasive Species and Ecosystem Health (Bugwood) was asked to take over What's Invasive in 2011 after the initial project period at UCLA expired. Bugwood worked with partners in the state of Florida and together they developed the smartphone application, Iv Got1 (http://apps.bugwood.org/apps/ivegot1/), to report invasive species occurrence and data housed and available through EDDMapS. Soon, other invasive species monitoring and management programs became interested working with Bugwood to develop tools. Users wishing to report invasive species in the western U.S. can do so through the EDDMapS West smartphone application or website. In 2012, when EDDMapS West was launched, reports came in equally from the website and application. As of 2015, the EDDMapS West application accounts for 89.53% of user contributed reports and 10.47% from the website. System-wide in 2015, 69.94% of reports from individuals are coming from a smartphone application (http://apps.bugwood.org/) and 35.06% are coming from the EDDMapS website. The most important factors in ensuring a successful application are a well-designed and easy to use application, marketing and publicizing of the project, and maintaining communication with the project partners and the reporters.

Keywords: smartphone application, data aggregation, citizen science, early detection, monitoring, management tools

**Engaging stakeholders on the management of invasive species: a step by step framework**

Ana Novoa<fnref n="1" />, <fnref n="2" />, Susan Canavan<fnref n="1" />, <fnref n="2" />, Cathleen Cybèle<fnref n="3" />, Sarah Davies<fnref n="1" />, Paul Downey⁴, Mirijam Gaertner<fnref n="1" />, ⁵, Sjirk Sjirk<fnref n="1" />, <fnref n="2" />, ⁶, Charles Griffiths⁷, ⁸, Philip Ivey<fnref n="2" />, Haylee Kaplan<fnref n="2" />, Sabrina Kumschick<fnref n="1" />, <fnref n="2" />, David Le Maitre⁹, John Measey<fnref n="1" />, Ana Nunes<fnref n="1" />, <fnref n="2" />, ¹⁰, David Richardson<fnref n="1" />, Tamara Robinson<fnref n="1" />, Ross Shackleton<fnref n="1" />, Louise Stafford⁵, Julia Touza¹¹, John Wilson<fnref n="1" />, <fnref n="2" />

<footnote n="1">¹Centre for Invasion Biology, Department of Botany and Zoology, Stellenbosch University 2. Invasive Species Programme, South African National Biodiversity Institute, Kirstenbosch Research Centre, Claremont, South Africa, Stellenbosch, South Africa</footnote>

<footnote n="2">²Invasive Species Programme, South African National Biodiversity Institute, Kirstenbosch Research Centre, Claremont, Cape Town, South Africa</footnote>

<footnote n="3">³Université de La Réunion, UMR PVBMT, 7 chemin de l'IRAT, Ligne Paradis, 97410 Saint Pierre, Réunion, Saint Pierre, Réunion</footnote>
<sup>4</sup>Institute for Applied Ecology, University of Canberra, Australian Capital Territory 2601, Canberra, Australia

<sup>5</sup>Nature Conservation, City of Cape Town, Berkley Road, Maitland, 7405, Cape Town, South Africa

<sup>6</sup>Department of Biodiversity and Conservation, Cape Peninsula University of Technology, P.O. Box 652, Cape Town, South Africa

<sup>7</sup>Marine Research (MA-RE) Institute, University of Cape Town, Private Bag X3, Rondebosch, 7701, Cape Town, South Africa

<sup>8</sup>Department of Biological Sciences, University of Cape Town, Private Bag X3, Rondebosch, 7701, Cape Town, South Africa

<sup>9</sup>Council for Industrial and Scientific Research, P.O. Box320, 7599, Stellenbosch, South Africa

<sup>10</sup>South African Institute for Aquatic Biodiversity, Somerset street, 6139, Grahamstown, South Africa

<sup>11</sup>Environment Department, Wentworth Way, University of York, Heslington, YO10 5NG, York, United Kingdom

Invasive species have major ecological and socioeconomic impacts in their novel ranges and many invaders have both benefits and costs. This often raises substantial conflicts between interest groups. As a result, there is increasing interest in assessing the perceptions of different stakeholders positively and negatively affected by invasive species. However, in most cases, there is still very limited collaboration between stakeholders – scientific researchers, the commercial sector, invasive species managers, policy makers, non-governmental organisations and the public. This often results in the failure to develop and implement sustainable management strategies for invasive species.

To better understand the need, barriers and options to engage stakeholders in invasive species management, a two-day workshop was organized in Cape Town (South Africa), with 20 participants working with biological invasions in different organizations. This included academics and managers working on a variety of organisms and in different areas (urban vs. rural) and ecosystems (terrestrial and aquatic). During the workshop, a stakeholder engagement framework for management of invasive species was built, as well as a detailed analysis of each of its steps. After the workshop, the framework was further discussed through additional meetings and e-mail communication including participants from Australia, Réunion and the United Kingdom. Finally, each step of the framework was further augmented by searching the scientific and grey literature.

The proposed engagement framework consists of 15 steps: (1) identify and categorize stakeholders, (2) identify the benefits and costs of the species or group of species, (3) explore influential stakeholders’ perceptions, (4) identify key stakeholders for engagement, (5) develop an aim for the management action and state the rationale for engagement, (6) engage key stakeholders, (7) re-explore selected stakeholders’ perceptions, (8) revise the aim for a management action, (9) develop management objectives and time frames with selected stakeholders, (10) design a management strategy, (11) empower stakeholders’ ownership and ensure ongoing communication, (12) implement management, (13) monitor management and, if management is still needed, (14) identify new stakeholders and benefits and costs of the target species and (15) re-explore stakeholders’ perceptions. Overall, this study aims to propose guidelines for effective engagement of stakeholders in invasive species management.

Keywords: conflicts of interest, stakeholders’ ownership, perceptions, engagement, management of invasive species
**Keynote 5 - Eradication, management & control of invasive species**

Fr-K-05

**Managing biological invasions in the Anthropocene**

*Christoph Kueffer*

*Institute of Integrative Biology & TdLab, ETH Zurich, Zürich, Switzerland*

In the Anthropocene invasion science and management are confronted with major new challenges: the scale of the problem is growing with increasingly more species being transported between continents, species move within biogeographic regions due to climate and land use changes (e.g. colonizing higher elevations in mountains or new habitats), native species can become problematic and alien species part of the solution, and natural areas are mostly surrounding by anthropogenic land exposing them more directly and immediately to invasion risks.

I will argue that the key for addressing these novel challenges is to reverse the division of labour between applied and basic research. Traditionally, in invasion science, we have first identified the biological principles driving biological invasions, then defined management needs and targets (e.g. lists of problematic species), and finally applied research and management was expected to work out the details of management strategies. More effective is to start with the management issues, develop a conceptual understanding of the different management problems, and derive specific research questions from such an understanding. Typical management problems are for instance: biosecurity, prevention and rapid response; strict protection of last "pristine" natural areas from invasions; low-cost maintenance and restoration of conservation-reliant nature reserves; landscape-scale management of coexistence landscapes characterised by mosaics of alien-species dominated and natural areas; management of novel ecosystems; or addressing global change impacts through the use of alien species, re-wilding, or assisted migration. By putting management problems first, the concerns and practical constraints of managers are taken serious from the beginning, multidisciplinary approaches involving natural, social and planning sciences become the rule, and we can develop an array of complementary and context-specific strategies that might seem contradictory (e.g. at once strict biosecurity or control of certain species and in certain areas *and* acceptance or even promotion of certain alien species in other situations) but will lead to more socially acceptable and effective management strategies. One solution for all problems approaches do not work anymore.

Keywords: biological invasions, management
Session 9 - Eradication, management & control of invasive species

Fr-S9-01

**Cross-fertilizing weed science and invasion science: *Ambrosia artemisiifolia* as an ideal bridge species**

Heinz Müller-Schärer<fnref n="1" />, Bruno Chauvel<fnref n="2" />, Gerhard Karrer<fnref n="3" />, Gabriella Kazinczi<fnref n="4" />, Per Kudsk<fnref n="5" />, Alfons Oude Lansink<fnref n="6" />, Urs Schaffner<fnref n="7" />, Carsten Skjoth<fnref n="8" />, Matt Smith<fnref n="8" />, Maurizio Vurro<fnref n="9" />, Letty de Weger<fnref n="10" />, Yan Sun<fnref n="11" />, Suzanne Lommen<fnref n="1" />

Weed science and invasion science have developed as two rather distinct research areas, with different institutions and researchers involved. This is partially due to the fact that the two disciplines indeed deal with different plant species, different target habitats and ecosystems, and that they are also committed to different stakeholders. Common ragweed, *Ambrosia artemisiifolia* is one of the economically most important invasive alien species (IAS) in Europe and elsewhere and constitutes an ideal species to create synergies between the “old” weed science and the “young” invasion science as it affects several sectors. It causes huge economic costs both for public health due to its highly allergenic pollen, for agriculture as it grows as a weed in many crops in Europe, where it is hard to control, as well as partially to biodiversity by colonizing habitats of high conservation value (e.g. tall herb communities, open forests) and spreading along linear transport structures (rivers, roads, railways).

We will outline how we, in the framework of an international research program, deliberately created synergies between very diverse fields of expertise to advance impact assessment and sustainable management of common ragweed European-wide. We first list differences in the setting, focus and strengths between weed science and invasions science and outline some early successes of inter-linking the strong points of these two disciplines. These include the elaboration of guidelines for habitat-specific integrated management of common ragweed, initiating studies on biological control candidates, linking plant occurrences to aerobiology and public health, the setup of a comprehensive economic ragweed impact assessment and management evaluation, and contributing to a European regulation of IAS and concerted trans-European action plans, especially focussing on biological control and on involving multiple

<footnote n="1">¹Department Biology, University of Fribourg, Chemin du Musée 10, Fribourg, Switzerland</footnote>

<footnote n="2">²INRA, Agroécologie, Dijon, France</footnote>

<footnote n="3">³Institute of Botany, University of Natural Resources and Life Sciences Vienna, Gregor Mendel Strasse 33, Vienna, Austria</footnote>

<footnote n="4">⁴Kaposvár University, H-7400 Kaposvár, Guba S. str. 40, Kaposvár, Hungary</footnote>

<footnote n="5">⁵Department of Agroecology, Aarhus University Forsoegsvej 1, Slagelse, Denmark</footnote>

<footnote n="6">⁶Business Economics group, Wageningen University and Research Centre, Hollandseweg 1, Wageningen, Netherlands</footnote>

<footnote n="7">⁷CAB International Switzerland, Chemin des Grillons 1, Delémont, Switzerland</footnote>

<footnote n="8">⁸University of Worcester, National Pollen and Aerobiological Research Institute, Henwick Grove, Worcester, United Kingdom</footnote>

<footnote n="9">⁹Institute of Sciences of Food Production, National Council of Research, via Amendola 122/O, Bari, Italy</footnote>

<footnote n="10">¹⁰Department of Pulmonology, Leiden University Medical Center, Albinusdreef 2, Leiden, Netherlands</footnote>

<footnote n="11">¹¹Plant Evolutionary Ecology, Institute of Evolution & Ecology, University of Tübingen, Auf der Morgenstelle 5, Tübingen, Germany</footnote>
stakeholders. Finally, we highlight how the multi-forked “Ambrosia approach” can be used as a template for establishing international and interdisciplinary consortia towards (i) a comprehensive impact assessment, elaboration of efficient management options and subsequent success evaluation of IAS that impact various sectors, habitat types and regions, (ii) an interdisciplinary and more sustainable management of crop weeds in an agro-ecological context, and (iii) fostering novel insights into key ecological concepts related to species spread and management.

Keywords: ragweed, Ambrosia, management, international, biological control, health, weed, plant invasion,

Fr-S9-02

## Environmental drivers of European-wide variation in *Ambrosia* pollen and seed production, and implications for management of this invasive, allergenic species

Suzanne Lommen<fnref n="1" />, Caspar Hallmann<fnref n="2" />, Eelke Jongejans<fnref n="2" />, Heinz Müller-Schärer<fnref n="1" />

The invasive common ragweed, *Ambrosia artemisiifolia*, is readily established in most European countries, *and in very diverse habitats*. This annual plant produces extremely high amounts of pollen and seeds, forming a reason of concern due to the highly allergenic properties of the pollen, and the adverse effects of the resulting high plant densities on crop production, respectively. To eventually better manage the species, it is vital to understand natural variation in pollen and seed production of *A. artemisiifolia* populations. We here first present the results of a study on the environmental factors driving pollen and seed production of *A. artemisiifolia*. In the framework of a European-wide research network, over 20 teams participated in an in-depth field study, including more than 40 *A. artemisiifolia* populations across the European continent, covering a wide range of climates and habitats. For each population we assessed the density and performance of *A. artemisiifolia* within subplots, and collected data on environmental variables likely affecting these properties. We show that variation in pollen and seed production varies largely both between, and within populations, resulting from variation in densities as well as in individual plant sizes. We compare the power of models at three different spatial scales (the region, the site, and the subplots) in explaining this variation. We found specific drivers at the scale of the site and the subplots related to the weather and the vegetation to be most important, and we discuss their implications for *Ambrosia* management. We then present demographic models of *A. artemisiifolia* parameterized by the field data, and integrate experimental data on new management strategies (vegetation management and biological control) to project the long-term effects of these strategies for different populations.

Keywords: common ragweed, invasive plant, health problems, field survey, plant performance, demography

<footnote n="1">¹Dept. of Biology, University of Fribourg, Fribourg, Switzerland</footnote>

<footnote n="2">²Animal Ecology and Physiology, Radboud University, Nijmegen, Netherlands</footnote>
**Long-term control of *Impatiens glandulifera* in a Swiss Forest: does zero-tolerance pay off?**

Janine Saegesser, Daniel Fischer, Kathrin Fischer

*Office of Waste, Water, Energy and Air, Building Department, Canton of Zurich, Zurich, Switzerland*

Himalayan balsam (*Impatiens glandulifera*), native to India, is an invasive plant in most European countries and negatively affects the invaded ecosystems. There are hardly any reports of long-term success in controlling this species. Therefore, it is unknown how much effort is needed to eradicate the species in specific ecosystems.

To test the efficacy of an intensive control procedure, an experiment was set up in 2012 in a small isolated forest (10 ha) in the Swiss midlands (375 m.a.s.l.), strongly invaded by *I. glandulifera*. We hypothesized that frequent weeding is key to prevent seed production and propagation by this species, which flowers from June to November. From 2012 to 2014 the forest was searched for *I. glandulifera* eight to nine times per year, and five times in 2015, pulling out all plants with the roots. The number of removed plants and working hours were recorded each time.

Results show a strong decline in the number of plants (from 101'000 ha-1 in 2012 to 2'150 in 2013, to 25 in 2014, and to 4 in 2015). Assuming that 30'000 seeds were produced per m2 in the original dense population (literature value) and no new seeds were produced after 2011, plant numbers in 2013-2015 indicate that more than 99.999% of the seeds from 2011 died, were eaten or germinated in 2012, whereas only 0.0007% survived until 2013 or longer.

The working effort per hectare for removing the plants declined from 104 h (2012) to 55 h (2013) to 48 h (2014) to 25 h (2015). The decrease rate was lower than in the number of plants because of the time needed to search the entire area. The effort cannot be reduced below a certain minimal level, which depends on the search area and not on the number of remaining plants.

Since a complete eradication of the population was not yet achieved in 2015, this project will be continued for another season. Results will demonstrate the feasibility and needed effort for a complete eradication through rigorous and frequent weeding and therefore help managers decide whether this is a suitable management strategy in similar forest ecosystems.

For a complete eradication it is crucial that all plants are removed and that none produces a single seed: zero-tolerance is necessary! This requires a high effort initially, followed by a smaller but continued control effort over several years (weeding every 3-4 weeks during the whole flowering period). We propose that it is more efficient to begin removal in a small area, but remove the invasive plant rigorously. Removing it in large areas only once or twice per year might be a waste of resources.

Keywords: *Impatiens glandulifera*, forest, management, eradication, control, effort
# Making the psyllid work: the biological control of Japanese knotweed in England and Wales as a study system to understand and manage biological invasions

Pablo González-Moreno<fnref n="1" />, Alex Brook<fnref n="2" />, Kate Constantine<fnref n="1" />, René Eschen<fnref n="3" />, Daisuke Kurose<fnref n="1" />, Corin Pratt<fnref n="1" />, Nikolai Thom<fnref n="1" />, Sarah Thomas<fnref n="1" />, Richard Shaw<fnref n="1" />

Japanese knotweed (Fallopia japonica (Houtt.) Ronse Decr. 1988) is an invasive perennial weed of Asian origin that is widespread in Europe and North America, where it causes serious economic and environmental damage. Conventional chemical and mechanical control methods are unfeasible because of the widespread distribution and frequent riparian occurrence of this species. Thus, classical biological control using a specialist antagonist from the native region of the weed was considered suitable as an alternative management method in England and Wales. A research programme carried out at CABI quarantine facilities revealed that the herbivorous insect *Aphalara itadori* Shinji (Homoptera: Psylloidea) is highly specific to Japanese knotweed. Based on these studies, the psyllid *A. itadori* was licensed for release in England and Wales. Three release phases have been made since 2010 including an intense monitoring programme mainly focused on any potential negative impact of the agent on Japanese knotweed and the receiving environment. Here we present the results of the release of *A. itadori* and the monitoring efforts carried out until 2016. The first two phases of the release (2010-2014) considered eight isolated Japanese knotweed stands. Despite the large number of adults released and the observation of eggs and nymphs at several sites, the establishment of the psyllid was not successful. The following release strategy (2015-onwards) builds on the theoretical framework of biological invasions and ecological theory to disentangle the different barriers the psyllid must face to establish viable populations in the wild. We review the studies done so far in the system *A. itadori – F. japonica* in relation to climate matching, biological interactions and propagule pressure to elucidate the potential limitations for the establishment of the psyllid and to propose further recommendations. This long term project shows how linking studies on biological control and biological invasions might provide a significant advance on our understanding of the invasion process and facilitate an integrated management approach.

Keywords: biological control, japanese knotweed, weed, aphalara itadori

<footnote n="1">¹CABI, Egham, United Kingdom</footnote>

<footnote n="2">²Ebsford Environmental, Bridestowe, United Kingdom</footnote>

<footnote n="3">³CABI, Delémont, United Kingdom</footnote>
# How to deal with cat (*Felis silvestris catus*) management on a large and inhabited island?

Pauline Palmas<fnref n="1" />, <fnref n="2" />, Elsa Bonnaud<fnref n="2" />, Raphaël Gouyet<fnref n="1" />, Malik Oedin<fnref n="1" />, <fnref n="4" />, Alexandre Millon<fnref n="3" />, Corentin Chaillon<fnref n="1" />, Frédéric Rigault<fnref n="1" />, Jean-Jérôme Cassan<fnref n="5" />, Eric Vidal<fnref n="1" />

Invasive populations of feral cats (*Felis silvestris catus*) strongly threatened wildlife on worldwide islands and particularly native species. Feral cats have invaded New Caledonia archipelago from seashore habitats to the highest altitude forest (1628m), most of these habitats harboring unique species assemblages. We have already demonstrated in a previous study that cat predation at archipelago scale is huge especially on reptiles (Frequency of Occurrence (FO): 42%) and flying foxes (up to 30% in some humid forests), most of them being endemic, and petrels (FO: up to 25% in some mountain areas). Here, we aim at mitigating cat impact on Pindaï peninsula (10 km<fnref n="2" />), located in the North of the New Caledonian mainland. We studied cat recolonization process by estimating cat population size before and after a feral cat control. We used camera traps as "capture" method and calculated 3 indicators: i) abundance index; ii) minimum number of individuals and, iii) individual capture histories using the spatially explicit capture-recapture (SECR) model to calculate density. Before feral cat control, we obtained 54.5 detections/100 camera trap-days from a total effort of 889 camera-trap days over 1 month. We individualized 25 feral cats from these pictures and the density calculated was 2.02 individual/km<fnref n="2" />. Then, 35 feral cats were live-trapped for a total of 1240 trap-days over 2 months. Traps were checked twice a day and as soon as a cat was trapped the veterinary in charge proceeded to the euthanasia. 3 months after the end of feral cat control we obtained 43.32 detections/100 camera trap-days from a total effort of 1228 camera-trap days over 1.5 month. We individualized 28 cats and the preliminary density calculated was between 1.8 and 1.9 individual/km<fnref n="2" />. Our study confirms camera-trapping as a useful tool to calculate the minimum size and density of a targeted cat population. This cat population has recovered, with almost the same amount of individuals, in only 3 months after the end of cat control. This recovery is mainly due to the colonization of new individuals that re-invaded this peninsula freed from most of resident feral cats. These results demonstrated a rapid recolonization process by feral cat leaving in close vicinity of this peninsula.

Keywords: feral cat, invasive predator, CMR analysis, SECR analysis, camera trap monitoring, trapping, invasive species control

<figure><img src="image_13.png" /></figure>

<footnote n="1">¹Institut méditerranéen de biodiversité et d'écologie marine et continentale (IMBE), Aix-Marseille Université, UMR CNRS-IRD-UAPV, UMR 237 IRD, Centre IRD Nouméa BP A5, 98848, Nouméa Cedex, Nouvelle-Calédonie, Nouméa, New Caledonia</footnote>

<footnote n="2">²Unité Écologie, systématique et évolution, Equipe Écologie des populations et des communautés, Université Paris-Sud 11, UMR 8079/UPS/CNRS/AgroParisTech, Bât. 362, 91405 Orsay cedex, France, Orsay, France</footnote>

<footnote n="3">³Institut méditerranéen de biodiversité et d'écologie marine et continentale (IMBE), Aix-Marseille Université, UMR CNRS-IRD-UAPV, Europôle de l'Arbois, BP 80, 13545, Aix-en-Provence, France, Aix-en-Provence, France</footnote>

<footnote n="4">⁴Institut agronomique néo-Calédonien, Diversités biologique et fonctionnelle des écosystèmes, Port Laguerre, Paita, New Caledonia, Paita, New Caledonia</footnote>

<footnote n="5">⁵Direction du développement économique et de l'environnement (DDEE), Koohnê (Koné), Province Nord, New Caledonia, Koné, New Caledonia</footnote>
Topic continued from previous session

Fr-S10-01

# Spread of *Vespa velutina* in Italy: natural diffusion, human-mediated dispersion and monitoring intensity to improve the management activities

Simone Liov, Marco Porporato, Daniela Laurino, Aulo Manino, Sandro Bertolino

Department of Agricultural, Forest and Food Sciences, University of Turin, Grugliasco, Italy

*Vespa velutina* Lepeletier 1836 is an Asiatic hornet species introduced in France in 2004. The species quickly colonized many European countries, such as Spain, Portugal, Belgium, Italy and Germany; in Italy first nests were discovered in 2013 in the northwest part of the country. *V. velutina* actively preys honeybees and wild insects, and could exert a negative impact on apiculture, natural ecosystems and human well-being. For these reasons, monitor and control activities recently started in Italy thanks to the work of many beekeepers and volunteers, together with a European Life Project (LIFE14 NAT/IT/001128 STOPVESPA) which aims to develop new tools and methods for controlling the species.

*V. velutina* could spread by natural diffusion or through passive transports of inseminated queens. In the first case the spread will be progressive and predictable, while human-mediated transports leads to the unpredictable colonization of areas even far away from the current distribution range.

Aims of this work are: i) reconstruct the spread of *V. velutina* since his arrival in Italy and establish a method to disentangle the natural diffusion from human-mediated transportation; ii) define buffer zones with different monitor and control intensity around the current Italian distribution range of the species with different likelihood of nests probability. The analyses were performed based on nests distribution, cluster analysis and nearest neighbour analysis of nests in respect to possible source sites of the previous year.

The range of the species increased exponentially from 205 km² in 2013 to 346 km² in 2014 and 930 km² in 2015 (R² =0.97; F =32; p =0.11). The mean linear spread rate was 18.3 ± 3.3 km/year, and follows a linear trend (R² =0.99; F =200; p <0.05). A cluster analysis of nests distribution allowed to identify 17 core-areas enclosing 90% of the nests in 57 km², with a mean nest density of 2.9-3.5 nests/km². Over this threshold the inclusion of others nest quickly increased the overall area.

Mean distances of nests observed in 2015 from possible source sites were used to define areas were the species could naturally spread in 2016. The estimated probabilities were: 33.5% within 500 m from the current range, 52.5% within 1 km, 75.1% within 2 km, 92.3% within 5 km and 97.7% within 10 km. Three expansion models were then elaborated at 700, 900 and 1200 m a.s.l., considering the altitude limits were nests and adults were observed.

These results could be used to improve the effectiveness of *V. velutina* control, and better focusing possible expansions areas.

Keywords: Asian yellow-legged hornet, domestic and wild bees, range analysis, species distribution, drivers and pathways, monitoring intensity
The EU Biodiversity Strategy [1] aims to halt the loss of biodiversity and ecosystem services in the EU and help stop global biodiversity loss by 2020. This Strategy sets out 6 targets, one of which is to combat invasive alien species. In implementation of this, the EU Regulation on invasive alien species [2] entered into force on 1 January 2015 (the IAS Regulation).

At the core of the IAS Regulation is a list of invasive alien species of Union concern (the Union list). Species for inclusion on the Union list are considered following a proposal of the Commission or the request by any of the EU Member States.

The European Commission is mandated to adopt and update the Union list as appropriate by following the criteria laid down in the IAS Regulation. In this, the Commission is assisted by a Committee in which the 28 EU Member States are represented. The Commission can only adopt the Union list and its updates with the positive opinion of this Committee. A Scientific Forum, with experts appointed by the Member States, is also consulted during this process.

The first Union list is expected to be adopted in the course of July 2016. Updating this list is an ongoing process and information on species under consideration for future updates can be found on a dedicated webpage [3].

The IAS Regulation foresees three types of intervention to be applied across the EU in relation to the species on the Union list: (1) prevention, (2) early detection and rapid eradication of new invasions, and (3) management of invasions that are already widely spread.

The European Commission progressively establishes an information support system necessary to facilitate the application of the IAS Regulation. The core of this system is the European Alien Species Information Network (EASIN) [4].

**References**

[1] http://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:52011DC0244

[2] Regulation (EU) No 1143/2014 of the European Parliament and of the Council of 22 October 2014 on the prevention and management of the introduction and spread of invasive alien species: http://eur-lex.europa.eu/legal-content/EN/TXT/?qid=1465832789495&uri=CELEX:32014R1143

[3] http://ec.europa.eu/environment/nature/invasivealien/index_en.htm

[4] http://easin.jrc.ec.europa.eu/

Keywords: EU Regulation, invasive alien species
**Consistency of impact risk assessments across assessors**

Montserrat Vilà¹, Pablo González-Moreno², Marc Kenis³, et al.

¹Estación Biológica de Doñana (EBD-CSIC), Sevilla, Spain

²CABI, Egham, United Kingdom

³CABI, Delemont, Switzerland

Risk assessments offer strong tools to managers and policy makers to support their decisions on problems caused by alien species. Risk assessments vary in their scope. While some focus on the probability of establishment or invasion, some also account for their potential to cause ecological or economic impacts.

Within the WP3 COST Action AlienChallenge we tested alien species from different taxonomic groups and habitats across several impact risk assessment protocols. In total 78 species (3 to 10 per taxonomic group) were assessed by 90 experts. Each species was assessed at least by 5 assessors.

We found a large divergence in species ranks among protocols. The consistency on species ranking was dependent on whether the protocol considered socioeconomic impacts or not. General knowledge about the species was negatively related to the consistency across assessors. In general results for freshwater species were more variable than for terrestrial species.

Keywords: risk assessment, impact, management