Paper by Scheper et al. 2013. Environmental factors driving the effectiveness of European agri-environmental measures in mitigating pollinator loss – a meta-analysis. Ecology Letters. DOI: 10.1111/ele.12128
Discussed at the Journal Club 14 June 2013
The Journal Club’s article was this time a meta-analysis. First, our PostDoc Anni kindly explained us the basic principles of meta-analysis. The article written by Scheper et al. followed the most common type of meta-analysis. The idea is to compare two sets of results, or two means (i.e. of species richness) and as a result you receive the proportional difference which is described as Hedges’ d.
The aim of the study was to quantitatively review how environmental factors affect the effectiveness of AES (agri-environmental schemes) focusing on pollinating insects. The review included 71 studies that fulfilled the desired criteria which we thought was good job done from the authors even though pollinators have been a popular research topic.
Given that writing a meta-analysis requires a remarkably bigger effort than writing a systematic review article we discussed about the scientific value of meta-analysis. For people outside of scientific community (policymakers or other stakeholders) it probably does not make a big difference whether the review is a meta-analysis or not. In this specific case it is important on the whole to have a review on the subject because policy makers are the ones who make decisions on AES with its implications and researchers would naturally prefer that decisions made base rather on research than other influencing factors in the society.
In the scientific community a meta-analysis might give additional credibility because the studies included in the review are being tested in addition to conventional review. On the other hand, people tend to publish only significant results, so zero results are never seen in meta-analysis.
If researchers in the field more or less agree on the subject under study – as is the case in the importance of pollinators in agricultural landscapes – a meta-analysis can provide a more in-depth analysis and understanding on the subject that none of the individual studies could not.
Last we discussed the dilemma of the urge of bringing novel research results into each publication. Undeniably, the purpose of research is to create new knowledge but how can any kind of review be done if each publication is unique in its idea and methodology? Well planned reviews earn their credits in the labyrinth of countless publications especially in the field of biodiversity where two-way communication between researchers and policymakers is vital for obtaining the target to halt biodiversity loss.