, Volume 21, Issue 2, pp 300-303,
Open Access This content is freely available online to anyone, anywhere at any time.
Date: 08 Jan 2012

Rebuttal related to “Traits and Stress: Keys to identify community effects of low levels of toxicants in test systems” by Liess and Beketov (2011)

Identifying long-term community effects of low toxicant concentrations is one of the major challenges in ecotoxicology at present. Mesocosm investigations, which are one valuable tool to identify such long-term community effects, face the problem that results are obscured by confounding factors and high variability between replicates (Sanderson et al. 2009). This problem is even greater when assessing long-term effects of toxicants because inter-replicate variation increases with time. Under such conditions, multivariate analyses on species data such as usually conducted with PRCs dramatically lose power to identify statistical links. With the SPEARmesocosm approach based on the investigations of Liess and von der Ohe (2005), we are aiming at resolving these shortcomings. We suggested a trait based aggregation of species that reduces the variability of community measures to reveal causality between exposure and effect for mesocosm experiments. We also show that this approach offers adv...