Risk assessment and risk management of transgenic trees

Dear Sir/Madam,

As a member of the Belgian Biosafety Council, I was implied in the evaluation of poplar trees. I was also the supervisor of Gaetan Vanloqueren who achieved a thesis on “Innovation in the era of transgenic plants” (e.g. Vanloqueren and Baret, 2008).

I will comment on two aspects of the previous contribution of Hans Bergmans and Steve Strauss.

Concerning apple trees, I consider that

1. A risk assesment should be based on scientific data and not on « general experience ». Do we have clear data or model on the impact of transgenesis on general fitness and invasiveness? Both issues are rather complex and the level of uncertainties on long-term impact is high.
2. As we are dealing with a small scale field experiment in this case, we have not yet had extensive discussions on topics that may become important at later stages, such as changes in agronomic management, as these are not (yet) actual (quotation of Hans Bergmans). This situation is a very important issue. I don’t understand why management and agronomic issues are not dealt with at early stages of the evaluation. Indeed, three reasons support an early assessment of these issues: 1) they require long term studies that should be started as early as possible, 2) they may help to design more precise risk assessment on specific aspects. It is difficult to assess risk for soils or ecosystems if the management and agronomical conditions are not determined, 3) agronomical considerations are important to define the relevance of the innovation.
3. In a specific study on apple trees (Vanloqueren, 2006), we showed that transgenic plants for disease resistance are not the only solution to this problem and that, in a problem-driven approach, more than twenty different strategies of innovations are possible. In a balanced cost-benefit approach, these different strategies should be compared.

Concerning poplar, I consider that :

4. My extensive field research with transgenic trees over the last 15 years  :Dr. Strauss is a specialist of the production of transgenic plants and not a specialist of risk assessment.  I really appreciate his contribution but there is some conflict of interest in this case, as Dr. Strauss produces transgenic poplars.
5. When considering specific novel modifications, it would be appropriate to consider the degree of novelty that is already practiced in breeding programs. The transgenic plant issue is not a question of novelty only. The public and political decision is to assess the transgenic plants. Our role, as experts, is not to discuss the opportunity of this evaluation. Our mission is to achieve this evaluation on a scientific basis.
6. Where a transgenic modification is clearly less novel than an accepted method of conventional breeding, it would be appropriate to exempt it from regulation entirely : I am very keen to know the definition of “less novel”  (see also previous remark).
7. the possibility of evolutionary increase should not be assumed in risk assessment, given that most genetic manipulations are directed at highly managed environments such as plantations, not at success in the wild, and most genes for biotic stress resistance are unlikely to be sustainable given the rapid relative evolutionary rates of pest populations compared to that of wild or feral trees. : scientific references in support of these assertions will be very welcome. If the affirmation on evolutionary rates is true, I don’t see the interest of producing transgenic trees.
8. Finally, with respect to small and short term field trials (e.g., below 10 to 100 hectares, below 10 years), the scale of possible release if often so small that the likelihood of adverse impact is extremely low and remote, even if there is a small release of seeds or pollen.  However, where provisions for harvest prior to flowering occur, or harvest of trees in the vicinity of the trial occurs (and thus most matings and regeneration), the release is almost nil compared to conventional breeding.  Strict regulations of field trials are therefore inappropriate, especially given their critical importance for risk assessment research, as discussed below. Unfortunately, in an ecosystem, there is no strict relationship between the scale and the effect. In invasiveness for example, there is many example of large-scale ecological damages due to a minuscule initial event.
9. Models are essential for risk assessment - The combination of field data to calibrate models, and models that take into account realistic details of the environment, genes, traits, fitness, demography, etc can provide very useful estimates of the range of risk possible over decades to centuries.  Sensitivity analysis allows the reliability of the model to be directly assessed.  See the work by DiFazio cited below for one example.  This allows investigations of risk scenarios that extend far beyond experimental time frames for trees.  I fully agree but the models do not require data from trials with transgenic plants. A calibration is possible with normal plants or data from confined trials (in greenhouses for example). As transgenic related risk is in many respect irreversible and considering the specific characteristics of trees (long term production of pollen, large scale plantations, monitoring on very long periods), model-based risk assessment have to be an absolute prerequisite before any kind of trial (small or large scale).

Trees have specific plant species: their lifespan may exceed the lifespan of human experimenters, they are planted in large area, they are impossible to isolate from the wild ecosystems, they have a major impact on biodiversity. Considering these specificities, they require the development of specific procedure including the use of models prior to any outdoor dissemination and an early assessment of the relevance of the proposed modification.

These remarks reflect my personal views and are not made on behalf of the Belgian Biosafety Council.

As I am not associated with industries producing transgenic plants and I am not contributing to the molecular or biotechnological aspects of transgenic plants, I declare that I have no conflict of interest considering the risk assessment of transgenic plants.

Philippe Baret, Professor at the Universite de Louvain (Louvain-la-Neuve, Belgium)


Vanloqueren G., Baret P.V. (2008)
Why are ecological, low-input, multi-resistant wheat cultivars slow to develop commercially? A Belgian agricultural ‘lock-in’ case study.
Ecological Economics 66:436-446

Vanloqueren, G., Baret, P.V.  2004
Les pommiers transgéniques résistants à la tavelure - Analyse systémique d'une plante transgénique de "seconde génération".
Le Courrier de l’Environnement de l’INRA (52):, Septembre 2004.

I would like to submit some comments regarding the contribution of prof. Baret:

By and large I agree with his comments, the main question is how to do risk assessment of field experiments at early stages, and how to initiate the risk assessment research the resukts of which will be needed later on.

Indeed, in the example that I gave, quoted in paragraph 2 of prof. Baret, we are dealing with a small scale field experiment, and according to our regulations we do a risk assessment of the field experiment as such. I have indicated that a number of discussions will become actual at later stages, and we will take them into account when risk assessment of larger scale longer term field trials become actual.
That does not preclude that we can, and probably should, have these discussions now already, it just means that these discussions at this stage do not influence the risk assessment of the small scale short term field trial. This should be assessed on its own merits.

I fully agree that it will probably only be possible to perform a risk assessment of larger studies that last for a longer period, if relevant empirical data are available. Necessary studies may take a long time, and applicants that want to perform larger and longer studies should take that into account. Governments may start the discussion on risk assessment of these cases early, and may consider if they want to fund risk assessment research for certain topics that they think are important (as we did for instance in our ERGO <http://www.nwo.nl/nwohome.nsf/pages/NWOA_6JNP94_Eng> project).

But all this does not directly influence the risk assessment of a specific small scale field experiment, even if we agree with the comments in paragraph 8, that small scale field experiments are not always as useful for collecting empirical data on the ecological behavior of the transgenic trees. The impact of the experiment will be negligible anyhow. It is up to the applicant however to decide if he wants to perform a small scale field experiments to evaluate characteristics of the GMO under field conditions. This is also an appropriate way forward in traditional breeding.
Whether strict regulations are appropriate or not is dependent on the outcome of the discussion how the conclusions of the discussion of precautionary approach for this case. Different competent authorities may reach different conclusions here.
But it is obvious that risk assessment research studies should be done under circumstances that meaningful answers for risk assessment can be generated. And indeed, as prof. Baret mentions in paragraph 9, many very relevant studies can be done with non-GMO trees, which would evade problems of permitting large scale GMO field experiments.

I just wanted to add a point of clarification to this discussion.  In a few places the phrase ‘risk assessment research’ has been used.  Research is – or should be – aimed at testing a specific hypothesis.  On the other hand, risk assessment is a process or procedure.  The procedure itself may not change under different circumstances, but the specific factors addressed and relevant information would differ on a case-by-case basis.  Research can provide data or information on specific aspects of trees that could be useful in a risk assessment, and presumably this is the kind of research to which this phrase is referring.  However, we should be careful that this phrase is not confused with a concept of doing research to test the hypothesis that there is or is not a risk.  Nothing is without risk, yet most people (perhaps thankfully) are unaware of the risks that they take routinely every day.  Risk assessments use the available data to gain an understanding of possible outcomes, and estimates of whether these are likely or unlikely.  The reality is that for any situation there can never be complete or perfect information.  Based on the risk assessment, decisions can then be made on a particular course of action (risk management) – in this case perhaps, to allow a field trial to proceed or not.