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In the agricultural and natural environments, GM crops and their transgene products will come into contact with hundreds of non-target species with important ecological functions.

How do you assess risks to such species and to biodiversity in your environment? Which species and ecological processes are most at risk?

There are too many species to assess all potential effects individually. It is essential to evaluate, rank and select the species and ecological processes to identify those possibly most affected by the GM crop for further assessment.

Step 1. Identifying Ecological Functional Groups. Species and ecological processes can be divided into ecological functional groups – such as predators, pollinators and decomposers – that relate to possible environmental risks. Some of these may be:
- disruption of pest predators may result in increased pest densities and damage
- reduced pollination may result in lower crop yield, seed and fruit production
- fewer decomposers may reduce soil fertility, but may reduce greenhouse gas emissions (a possible benefit)

Species or ecological processes are classified to the groups. Each identified ecological functional group is analyzed separately in Step 2.

Step 2. Association with Target Crop and Significance. In each functional group from Step 1, all relevant species and ecological processes associated with the target crop in your country are ranked for their importance.

- how closely associated is the species or ecological process with the crop?
- If the species or process were adversely affected, how significant would the adverse consequences be? Or, if the species or process were to benefit, could this cause a future pest or disease problem for local farmers?

Important species and ecological processes are retained for further analysis in Step 3.

Step 3. Exposure to GM Product: Preliminary Assessment. For the retained species and ecological processes, how likely is contact between these and the transgenic products produced by the GM plant?

What other ecological impacts on these species or processes are possible?
- impacts caused by altered crop management practices
- impacts caused by changes in the plant that affect behavior

This will reduce the number of species and processes to a manageable number all of which are more likely to be associated with a risk than those not retained.

These three steps analyze and synthesize existing information, using local expertise. This helps to identify and prioritize key knowledge gaps in biodiversity at the region or country level.

Step 4. Retained species and ecological processes can be specifically tested for an actual effect on them that may represent a possible risk. It is important to use methods that are relevant to the biology and food webs of the species or ecological process in their crop environment.

The results of these analyses lead to the description of possible hazard pathways. We develop a relevant hypothesis for each pathway, and experiments to test each of them. In some cases, one simple experiment may answer the hypothesis and confirm or refute a possible risk; in other cases a series of experiments may be necessary. We suggest experiments for pre-release testing in confined use (laboratory, greenhouse or screen house), and for small-scale field trials. We also provide guidance on criteria important for designing ecologically relevant experiments.

a flow chart of the methodology for prioritizing non-target species and ecological processes

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Pentatomid bug with boll weevil

parasitised caterpillar

spider on a cotton leaf

wasp parasitoid (Braconid)