Table 1: Regional case studies. Grey boxes indicate the actions undertaken for each case study.
The work carried out suggested a framework to identify and organize the main factors that could determine the implementation of coexistence in specific contexts.
These factors fall into three categories:
1.- Structural variables describing the characteristics of the agroecosystem (cropping systems, landscapes, meteorology, crop management) having an influence on gene flow.
2. - Organizational variables concerning farmers and grain collecting firms, explaining how they adapt their management according to certain constraints and rooms for manoeuvre. We identified two types of adaptation. Firstly, each actor mobilizes its own resources to various degrees, from technical choices in the short term, to more strategic in the long term: a farmer, for example, may adapt agricultural practices, change his rotations, or decide new investments, while a collecting firm may amend the planning of the grain collection or decide to invest in new storage capacity. Secondly, coordination is crucial, whether between farmers, collecting firms or between farmers and collecting firms. Here arises the question of practical feasibility of collecting and sharing information in a region.
3.- Characteristics of the introduction of GMOs. Coexistence implementation also depends on market conditions (relative prices of GM and non-GM products on the marketplace), on considered thresholds (which can differ from what is required by regulation, e.g., specific market requirements) and on traits (some traits –e.g., Bt traits which require refugia areas - may facilitate or constrain certain types of coexistence measures).
For given characteristics of GM introduction (crop density, marketshare of GM, threshold), we have highlighted the variability of structural and organizational factors, between regions and within each of them. Maize case studies, for example, have shown that the comparative sensitivity to gene flow was higher inside one region than between two remote European regions (e.g., Alsace and Aragon). In fact, landscape patterns (sizes and shapes of fields) may differ more within one region than between regions and this greatly affects coexistence features.
Based on the simulation results obtained in regional case studies, we have identified four major types of situations, the so-called pre-scenarios[1]: , that local stakeholders may have to deal with :
1) segregation at the silo level is feasible without any specific measures at the field level;
2) curative measures at harvest (selection of non-GM fields or parts of fields) allows meeting market requirements in terms of targeted thresholds;
3) preventive measures at the crop level (e.g., sowing dates) or at the system level (crop rotation, spatial arrangement of crops allows meeting market requirements,
4) coexistence is not possible because whatever the agronomic measures undertaken at the crop or system level, the targeted threshold cannot be met or requires non realistic measures.
For a given threshold and a given rate of introduction of GMOs in the landscape, limits between the pre-scenarios are defined by the sensitivity of the landscape to gene flow, as well as the capacity of actors to put them to work. Oilseed rape (OSR) is a particular problem because of the dynamics of volunteers in the cropping system. If farmers wished to return to conventional varieties after GM cultivation, the fields should be managed differently from those which have never been grown with GM OSR. For these fields, a thorough control of volunteers will be required in order to meet thresholds. Even if GM and non-GM OSR fields are spatially segregated (i.e., if non-GM varieties are never grown in fields previously cultivated with GM varieties), proper management is required to reduce both spatial and temporal gene flow due to volunteers.
Role-playing games carried out in Alsace and Beauce made it feasible to test the relevance of pre-scenarios under realistic management situations. They demonstrated how players (farmers, collectors) would combine different management strategies in a more or less coordinated way, and how these strategies may evolve over time. It thus appears that risk assessment determines actions, such as the selection of "complying" or "non complying" quality harvests by the collecting firms according to their presumed GMO content and the targeted threshold firms are considering.
Risk assessment and management are not static and evolve according to feedback from experience. We observed that the effectiveness of measures undertaken at the field level was ensured only if the rules (i.e., agreement on the way to assess risks and on the measures to be implemented) were shared between the collecting firms and farmers. In addition, the role-playing games demonstrated that collating and sharing information at the territory level is essential to facilitate coexistence. This raises practical implementation problems that are not currently solved.
Three main processes determine how pre-scenarios may be embedded into global management scenarios:
1. the system and rules for collating and sharing information at the territory level,
2. the framework and procedures describing coordination between actors and,
3. learning processes (both individual and collective).
Based on these findings, contrasting global scenarios may be defined by considering different regulation approaches:
- A "bottom-up" approach, which freely allows the private actors (collector, farmers) to choose the best way to achieve the objectives of coexistence and to meet regulatory or market-based threshold requirements;
- A "top-down" approach, based on the strong intervention of public authorities with the implementation of compulsory uniform measures (e.g., isolation distances)
- and a "third way" approach, which provides a focused response of authorities to lift some constraints on information and coordination. between private actors, and allow some flexibility in the measures .
Each approach has advantages and disadvantages : the "bottom up" approach allows more flexible measures than the "top down" one, leading to subsequent lower costs. Moreover, it may help in dealing with management problems out of the scope of the GM regulations, such as specific requirements for “Identity Preserved” (IP) market. However, it may not prevent distrust from the general public and does not solve all the liability issues. The "third way" takes advantage of both local knowledge from individual stakeholders and the ability of public authorities to collect and share information at a large scale, in order to cope with practical problems raised by the implementation of coexistence measures.
[1]: The word “pre-scenario” is used because the pre-scenarios only cover a component of the overall picture and should then be integrated into overall management scenarios taking into consideration other factors than those affecting farm coexistence (see below).
