Elements of Environmental Monitoring Strategies

Presentation 1: Principles and procedures for medium- to long-term environmental monitoring. P. Jepson

Presentation 2: Strategies and tools for monitoring biodiversity and ecological function. A. Hilbeck

Presentation 3: Soil ecosystem monitoring methodologies. J. Thies

Paul Jepson reviewed monitoring principles based upon the Expert Consultation background review paper. Analysis of long-term biodiversity monitoring in agro-ecosystems tends to be retrospective, with time lags between data collection, analysis and response. Monitoring of functional, often abiotic, indicators has a better record for early detection of adverse impacts.

Decision making and effective responses are only possible when plausible mechanisms underlying effects are known, and when monitoring analysis has high inferential power. Measurements must also translate to the values and concerns of stakeholders in the final outcome if management responses are to be implemented. Post-release monitoring must consider functional, taxon-based and structural indicators to detect the drivers of change associated with GM cropping. Some farming systems will be more sensitive than others. Sensitive systems may be at intensification limits or ecologically fragile, with high species turnover rates and poor connectivity with natural areas. They may also be critically dependent upon the grower knowledge base, R&D support may be poor, and the policy environment may be inflexible.

Angelika Hilbeck discussed monitoring biodiversity and ecological functions in the context of European Union Directive 2001/18³ which requires monitoring for all GM commercial releases. Monitoring designs must be case-specific (to verify risks) and general (to detect unanticipated effects). A project of the German Federal Agency for Nature Conservation is identifying faunistic indicators using a species-ranking approach, which characterizes and ranks species by ecological function, occurrence, spatio-temporal abundance and relevance, and an impact pathway approach, which identifies hazard scenarios using ‘event-tree analysis’ and ‘fault-tree analysis’. The two tools are used in succession; the first prioritizes species based on characteristics and conservation goals independent of genetically modified organisms (GMOs) and the second subjects them to fault- and event-tree analyses to identify species at risk.

Janice Thies discussed methodologies for monitoring the soil ecosystem and its function. The soil provides many ecosystem services including decomposition and nutrient cycling. The agricultural soil food web, with crop residues as its base, includes decomposers (bacteria and fungi), and predatory protozoa, nematodes and micro-arthropods. GM crop residues have the potential to disrupt energy and material flows, and monitoring should be designed to detect detrimental changes in trophic structure and/or key ecosystem services. Soil scientists are yet to agree upon the factors that determine soil ecosystem integrity, and the level of change that might trigger concern. Promising indicators include the level of retention and form of soil organic matters⁴ , soil respiration rate, abundance of shredder species (collembola and mites), microbial biomass, nitrogen mineralization and nitrification, soil glomalin concentration, and molecular indices of soil community structure.

Discussion Summary

• Before/after comparisons, or comparisons with control (without GM crop) areas, are essential if analysis of monitoring data is to have inferential power. Data must span the whole cropping system.


• Background data required for all systems includes soil parameters, climatic conditions and crop management (fertilisers, crop protection chemicals, crop rotations and previous crop history).


• Existing biodiversity measurements and abiotic measures of system conditions should be collated, and availability of monitoring expertise must also be established.


• Monitoring should focus on potential positive and adverse effects of concern to stakeholders.


• Available data on the turnover of GM crop residues in the soil should be compiled into a global database.


• Scientific experiments, undertaken by researchers to develop understanding of mechanisms, do not constitute monitoring; they are, however, essential precursors to effective monitoring because they provide a direct link between measures of change and the mechanisms that underlie such change if it is occurring.

³Directive 2001/18/EC of the European Parliament and of the Council on the deliberate release into the environment of genetically modified organisms and repealing Council Directive 90/220/EEC. http://europa.eu.int/eur-lex/pri/en/oj/dat/2001/l_106/l_10620010417en00010038.pdf
⁴Sohi et al. (2001). Soil Science Society of America Journal 65: 1121–1128.