Conducting model ecosystem studies in tropical climate zones: Lessons learned from Thailand and way forward

Little research has been done so far into the environmental fate and side effects of pesticides in the tropics. In addition, those studies conducted in tropical regions have focused almost exclusively on single species laboratory tests. Hence, fate and effects of pesticides on higher-tier levels have barely been studied under tropical conditions. To address this lack of knowledge, four outdoor aquatic model ecosystem experiments using two different test systems were conducted in Thailand evaluating the insecticide chlorpyrifos, the herbicide linuron and the fungicide carbendazim. Results of these experiments and comparisons of recorded fate and effects with temperate studies have been published previously. The present paper discusses the pros and cons of the methodologies applied and provides indications for i) possible improvements; ii) important aspects that should be considered when performing model ecosystem experiments in the tropics; iii) future research.

Research highlights
► Methodologies used overall seemed adequate to evaluate pesticide stress.
► Identification and sampling of tropical macroinvertebrates should be improved.
► Additional studies needed for different compounds and greater geographical scale.
► Different exposure regimes and ecosystem types should be simulated.
► Trophic interrelationship and recovery potential need to be evaluated.