INVADER-B - INVAsive plant species management in Portugal: from early DEtection to Remote sensing and Biocontrol of Acacia longifolia
Coordinator - Elizabete Marchante
Programme - Projetos de Investigação Científica e Desenvolvimento Tecnológico - 2010
Execution dates - 2013-07-01 - 2015-11-30 (29 Months)
Funding Entity - COMPETE e Fundação para a Ciência e a Tecnologia
Total Funding - 199 983 €
Proponent Institution - Centro de Ecologia Funcional, Universidade de Coimbra
Participating Institutions
Escola Superior Agrária, Instituto Politécnico de Coimbra

Invasive alien species (IAS) are widely recognised as a significant component of human-caused global environmental change, often resulting in major loss in the economic value, biological diversity and function of invaded ecosystems. Scientists, politicians (European Commission(3), Portuguese government) and several Organisations with worldwide spectrum (ISSG, IUCN, Millennium Assessment), all recognise the importance of this problem. The policy response to these threats, based on scientific knowledge, stands on an internationally agreed 3-stage hierarchical approach supporting: 1) prevention, 2) early detection & eradication, and 3) control & long-term containment. In this project, we aim to contribute to all 3 stages, through a series of tasks that fit in an integrated conservation strategy.

Public awareness is fundamental to prevention; the early-detection programme proposed will involve students countrywide, in gathering field data about IAS (task5), meeting stages 1) and 2). The scientific questions of the project (task 1-4) are related to the safe use of biological control; if achieved, this will be a major contribution for the control and long-term containment (stage 3) of Acacia longifolia, one of the worst IAS in Portugal. In addition, the project will contribute to key scientific advances since 2 novel approaches, amongst others, are included: 1) prediction of indirect effects of a biocontrol agent prior to its release; and 2) use of remote sensing (spectroscopy) to follow up effects of the biocontrol agent pos-release.

Portuguese law recognises 29 plant species as invasive, including A. longifolia. This is a woody legume with negative impacts at several levels of the ecosystem. This and other Acacia species are successfully controlled in South Africa by biological control. Despite broadly used worldwide, classical biological control for environmental invaders is not yet an option in Portugal and in Europe the first agent was only released in 2010, in the UK. The concern with non-target effects explains, at least partially, this "resistance". In Portugal, millions of Euros have been applied in projects aiming to control A. longifolia, using chemical and mechanical methods, with little success, mainly due to the species' prolific seed bank. In order to provide a viable and cost-effective alternative, our team has been studying the potential use of Trichilogaster acaciaelongifoliae, an Australian gall-forming wasp that targets seeds production of A. longifolia. This agent was released in South Africa over 25 years ago, reducing the seed production in 85-100%, without direct non-target effects (only negligible split over). Unfortunately, as with most species, quantitative surveys to demonstrate the overall effectiveness of the agent are lacking.

In Portugal, specificity testing (non-target direct effects) in quarantine is completed with promising results. Still, the indirect non-target effects, often pointed out as a setback of biocontrol cannot be hidden. Indirect non-target effects were shown for some biocontrol agents after introduction, but they were never predicted pre-release (for any species in the world). In this context, our scientific goals include: 1) measure impacts of A. longifolia at a still unexplored level: interaction networks of plant-galls and associated communities; 2) explore the networks to assess the indirect non-target effects of T. acaciaelongifoliae, both before (as a predictive tool) and after (as an assessment) its release; 3) use remote sensing to map the distribution of A. longifolia on selected areas (creating a valuable tool for management of the species); 4) explore the potential of remote sensing (spectroscopy) to follow the dispersal of the biocontrol agent, and 5) evaluate the establishment of the agent and its effects on A. longifolia, since release.

To invest in control without considering prevention & early-detection would make no sense, from a management point of view. Considering this, an IAS early-detection programme will be implemented, targeting students, aiming to engage them with the program and simultaneously raising their awareness about IAS.

This is an innovative, necessary and solid proposal that can significantly decrease costs associated to IAS management and contribute to scientific advances; it will greatly benefit from the experience of the team, working for more than 10 years with invasive plants. All the tasks are closely interconnected contributing to the same goal: the successful and scientifically supported management of IAS. The PI is young but she has been involved in most of the past and current projects of CFE/UC concerning IAS (from its conception), and has completed her PhD on the subject. This project will also benefit from the solid contribution of world experts.

Members on this project
Sabrina de Carvalho
Ruben Heleno
Nuno Sá
Research fellow
Lurdes Barrico
Hélia Marchante
Helena Freitas
Elizabete Marchante
Principal investigator