Invasion Biology: Specific Problems and Possible Solutions

Invasion Biology: Specific Problems and Possible Solutions

Interactive questions

Invasion Biology: specific problems and possible solutions

1) Why are introduced species problematic?

- they are from another country, so necessarily they must be bad

X they cancause ecological and/or socio-economic problems in invaded areas


Introducedspecies have been demonstrated to be much more likely than native species to cause problems, from biodiversity loss and ecosystem-function disruption to economic and health costs.

- species from other regions of the world never have beneficial effects

- they are never problematic

2) Which of the following characteristics applies to invasive alien species (IAS)?

- theirimpacts on ecosystem are always of short duration

- they are all well identified

- they always cause immediate, visible damage

Xthey generate various perceptions or opposed interests


One of the difficulties with dealing with IAS is that some stakeholders have interests in the presence of these species (e.g. wildlife traders), some have interests in low biosecurity measures that could limit IAS (e.g. international traders), and some stakeholders can be negatively affected by IAS.

3) Which of the following characteristics is specific to biological invasions?

- unlike pollution, overexploitation or climate change, biological invasions are only local problems and not an aspect of global change

- they are a major driver of biodiversity loss

- they are not caused by human activities

Xthey areneitherwell understood nor well known by the public


Biological invasions are similar to other major human-induced drivers of biodiversity loss and global change, but unlike them they convey definitions and concepts less intuitive for the general public, which may present them as a lesser threat.

4) To avoid the “deficit model”,what form of science communication should be preferred?

- one-way communication

- top-down communication

X multi-way discussion


The “dialogue model” works much better than the “deficit model”. It is a two- or multi-way discussion based on a genuine interchange with people that recognizes and incorporates differences in knowledge, values, perspectives and interests.

- communicating facts only, from scientists to others

5) Which of the following characteristics is false about the “dialogue model” of science communication?

- scientists engage with the public

- it is a multi-way communication

- it implies an authentic dialogue between scientists and citizens

X scientists are well trained for it


Scientists are seldom trained in any form of science communication, but the historical model that they are naturally more familiar with is the ineffective “deficit model” of expecting people to accept scientific facts, not the more effective “dialogue model”.

- it claims that knowledge is one of many factors for reaching decisions

6) Why is there low support from the public for actions against IAS?

- there is a lack of sympathy for these species

- actions never involve harming living beings

X the public often confuses invasive with introduced species


Not all introduced species are problematic, only a subset of introduced species will becomeestablished and spread but those will generally cause significant problems to the invaded areas and need to be identified, monitored and controlled.

- most IAS affect everybody, everywhere

7) What hinders the demonstration of the impact of IAS?

X There is often a lack of pre-invasion data on invaded ecosystems


Invasion impact can really be best demonstrated if one can compare an invaded ecosystem with a control (not invaded) ecosystem, and the invaded ecosystem before and after invasion, what has been called the BACI (Before After Control Invaded) protocol. Because one can seldom predict where invasions will occur, it is difficult to obtain such demonstration.

- Researchers do not put their efforts into measuring the impacts of IAS

-Impacts usually happen too quickly to be noticed

X It is hard to distinguish the impact of the IAS from the background noise of normal ecological variation


First, impacts may become visible only a long time after invasion. Second, natural ecosystems are constantly evolving, so it is tricky to show that the introduced species is responsible for a particular change. Third, each invasion event has its own characteristics, and it is difficult to anticipate the type of impact to look for. Last, ecosystems involve dozen, sometimes hundreds of interacting species, and impacts can be subtle and not easily discernable.

8) Which solutions is the standardization of the definition of IAS likely to bring?

- International lists of IAS, valid for all countries, will be produced

- Exotic and invasive species will be considered the same

X Across borders, laws and economic incentives will be put into place more effectively


Global standardisation will enable all countries to develop common action plans (each directed against their specific IAS), targeted at IAS only (and not alien but harmless species). It will also enable all actors to speak the same language (in the fields of law, science, politics, ethics, …) and think about this issue in an effective and comprehensive manner.

- It will make the concept more difficult to grasp by to the public

9) What can be done to avoid new introductions of potential invasive species?

- Stop all international exchanges, including trade and tourism

- Rely on public common sense

- Do not communicate with the public but rather to custom services

- Nothing can be done

X Enhance consistency and efficiency of police and legislative authority

Explanation: Numerous legislative texts and international treaties exist to limit the spread and impact of invasive alien species but due to a lack of people (number and skilled), congruity amongst legislative levels (international, regional, national and even international) and laws often impossible to apply (species identifications, species origin, etc.)