A perspective article recently published in Nature Ecology & Evolution (Haddaway et al 2020) nicely reviews various problems with ecological literature reviews and provides methodological solutions to address those problems. Nevertheless, we found that a key issue was not covered by the perspective article - the need to search and analyse literature published in languages other than English.
By reanalysing existing meta-analyses including both English- and Japanese-language studies, we show that effect sizes differ significantly between English- and Japanese-language studies, causing considerable changes in overall mean effect sizes and even their direction when Japanese-language studies are excluded (see figure below).
This piece was our initial attempt to review how language barriers affect science in two directions: (i) when compiling knowledge globally and (ii) when applying knowledge to local environmental issues.
In this paper we found that the availability of data stored in biodiversity databases is highly geographically biased (see figure below), and the proportion of English speakers in each country partly explains the distribution, with a fewer records per area stored for countries where English is not widely spoken.
The translatE project: our aims and progress so far in overcoming language barriers in conservation science. (2021) CBCS Tuesday seminar. Centre for Biodiversity and Conservation Science, The University of Queensland.
Is non-English-language literature important in science? (2020) Keynote presentation at the 2nd annual meeting of the Association for Interdisciplinary Meta-research and Open Science (AIMOS). Presentation slides available here.
Flying over the Tower of Babel: Implications of language barriers on shorebird conservation. (2020) Keynote presentation at the International Shorebird Twitter Conference 2020 (#ISTC20).