RT Journal Article SR Electronic T1 Systematic variability enhances the reproducibility of an ecological study JF bioRxiv FD Cold Spring Harbor Laboratory SP 080119 DO 10.1101/080119 A1 Alexandru Milcu A1 Ruben Puga-Freitas A1 Aaron M. Ellison A1 Manuel Blouin A1 Stefan Scheu A1 Thomas Girin A1 Grégoire T. Freschet A1 Laura Rose A1 Michael Scherer-Lorenzen A1 Sebastien Barot A1 Jean-Christophe Lata A1 Simone Cesarz A1 Nico Eisenhauer A1 Agnès Gigon A1 Alexandra Weigelt A1 Amandine Hansart A1 Anna Greiner A1 Anne Pando A1 Arthur Gessler A1 Carlo Grignani A1 Davide Assandri A1 Gerd Gleixner A1 Jean-François Le Galliard A1 Katherine Urban-Mead A1 Laura Zavattaro A1 Marina E.H. Müller A1 Markus Lange A1 Martin Lukac A1 Michael Bonkowski A1 Neringa Mannerheim A1 Nina Buchmann A1 Olaf Butenschoen A1 Paula Rotter A1 Rahme Seyhun A1 Sebastien Devidal A1 Zachary Kayler A1 Jacques Roy YR 2016 UL http://biorxiv.org/content/early/2016/10/10/080119.abstract AB Many scientific disciplines currently are experiencing a “reproducibility crisis” because numerous scientific findings cannot be repeated consistently1–4. A new but controversial hypothesis postulates that stringent levels of environmental and biotic standardization in experimental studies reduces reproducibility by amplifying impacts of lab-specific environmental factors not accounted for in study designs5–8. A corollary to this hypothesis is that the deliberate introduction of controlled systematic variability (CSV) in experimental designs can increase reproducibility. We tested this hypothesis using a multi-laboratory microcosm study in which the same ecological experiment was repeated in 14 laboratories. Each laboratory introduced environmental and genotypic CSV within and among treatments in replicated microcosms established in either growth chambers (with stringent control of environmental conditions) or glasshouses (with more variable environmental conditions). The introduction of genotypic CSV increased reproducibility of results in growth chambers but had no significant effect in glasshouses where reproducibility also was lower. Environmental CSV had little effect on reproducibility. This first deliberate attempt at reproducing an ecological experiment with added CSV reveals that introducing genotypic CSV in experiments carried out under controlled environmental conditions with stringent standardization can increase reproducibility by buffering against unaccounted lab-specific environmental and biotic factors that may otherwise strongly bias experimental outcomes.