TY - JOUR T1 - Systematic variability enhances the reproducibility of an ecological study JF - bioRxiv DO - 10.1101/080119 SP - 080119 AU - Alexandru Milcu AU - Ruben Puga-Freitas AU - Aaron M. Ellison AU - Manuel Blouin AU - Stefan Scheu AU - Thomas Girin AU - Grégoire T. Freschet AU - Laura Rose AU - Michael Scherer-Lorenzen AU - Sebastien Barot AU - Jean-Christophe Lata AU - Simone Cesarz AU - Nico Eisenhauer AU - Agnès Gigon AU - Alexandra Weigelt AU - Amandine Hansart AU - Anna Greiner AU - Anne Pando AU - Arthur Gessler AU - Carlo Grignani AU - Davide Assandri AU - Gerd Gleixner AU - Jean-François Le Galliard AU - Katherine Urban-Mead AU - Laura Zavattaro AU - Marina E.H. Müller AU - Markus Lange AU - Martin Lukac AU - Michael Bonkowski AU - Neringa Mannerheim AU - Nina Buchmann AU - Olaf Butenschoen AU - Paula Rotter AU - Rahme Seyhun AU - Sebastien Devidal AU - Zachary Kayler AU - Jacques Roy Y1 - 2016/01/01 UR - http://biorxiv.org/content/early/2016/10/10/080119.abstract N2 - 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. ER -