Due to the economic globalization, people introduce organisms into new habitats non-intentionally, intentionally or by inadvertence when organisms imported for a limited purpose then subsequently spread into new habitats. These species are, in the scientific discourse, called ‘exotic’ or ‘alien’. Some of these exotics thrive and proliferate in their new environment. Those species are referred by ecologist as ‘invasive’. The spread of introduced alien species (IAS) into native ecosystems and habitats is considered as the second largest cause of current biodiversity loss worldwide. In addition, the direct costs of IAS are immense. In contrast, global trade has enabled modern societies to benefit from the unprecedented movement and establishment of species around the world.The human dimension is the most unpredictable variable in any management programme to control IAS. Communication is a crucial part of a management strategy and it is not evident that it should be based primarily on ecological arguments. How to communicate to people about the need to control some of these species? How to make them aware of ecological – and therefore often considered as not entirely ‘their cup of tea’ – concerns? Misunderstandings and tension exist regarding the science, values, environmental ethics, and public policy relevant to invasive species, which are the subset of nonindigenous species that cause economic or environmental damage. Assesing how different public perceive exotics species, in general, and the problem of invasive species, in particular is thus a crucial part of a communication strategy as well as an evaluation of the feasibility of management strategies.This cluster aims: 1) at providing a framework for the evaluation of public perception of the invasive species problem in Belgium, 2) at identifying sociological constraints on the establishment of management strategies for invasive plant species including, 3) increasing communication skills of scientists and managers towards broad public on the matter of invasive species. Three projects launched in the frame of PADD-PODO II are concerned. The INPLANBEL (EV/27) research program presents objectives that are directly related to the ecological evaluation of invasive plant species in Belgium. The mixed action ECONET (MA/01) contains a sociological sub-part aiming at the evaluation of the feasibility of ecological network and at the communication with actors involved in ecological network. In this context methodologies are built that can be transferred to the problem of invasive plant species and more particularly to the analysis of perception by the broad public and definition of guidelines of communication strategies. The cluster LANDECOL (OA/00/013) aims at evaluating alternative strategies of nature conservation and contains a specific task questioning the possibility that nature conservation strategies should promote the spread of invasive species. The methodology used in the cluster will include four steps and will be based on the following methods. A structured synthesis on the ecological (scientific/expert) and sociological (lay-people) perception and interpretation of IAS will be realized with the aim to identify topics that may be prone to conflicts or contestation. Focus group meetings will be used to obtain a feed back on the most important topics identified in the theoretical synthesis from groups implicated in the INPLANBEL project and other target focus groups. A more detailed case study of the combined perception of the problem of invasive species and their environmental effect in Belgium will be realized for two different groups with different interest and reaction on IAS based on an large inquiry towards nature reserve managers and plant nurseries managers . All the actions will lead to the development of guidelines for communication on the problem of IAS. Main expected results are : 1) a structured synthesis of the perception by different kind of actors of IAS in regard to ecological definition and management objectives based on scientific analysis; 2) a structured synthesis of potential sociological constraints (acceptability / feasibility) on IAS management strategies; 3) structured guidelines on the way to communicate on IAS in regard of the perception of different public.