The widely held assumption that any important scientific information would be available in English underlies the underuse of non-English-language science across disciplines. However, non-English-language science is expected to bring unique and valuable scientific information, especially in disciplines where the evidence is patchy, and for emergent issues where synthesising available evidence is an urgent challenge. Yet such contribution of non-English-language science to scientific communities and the application of science is rarely quantified. Here, we show that non-English-language studies provide crucial evidence for informing global biodiversity conservation. By screening 419,679 peer-reviewed papers in 16 languages, we identified 1,234 non-English-language studies providing evidence on the effectiveness of biodiversity conservation interventions, compared to 4,412 English-language studies identified with the same criteria. Relevant non-English-language studies are being published at an increasing rate in 6 out of the 12 languages where there were a sufficient number of relevant studies. Incorporating non-English-language studies can expand the geographical coverage (i.e., the number of 2° × 2° grid cells with relevant studies) of English-language evidence by 12% to 25%, especially in biodiverse regions, and taxonomic coverage (i.e., the number of species covered by the relevant studies) by 5% to 32%, although they do tend to be based on less robust study designs. Our results show that synthesising non-English-language studies is key to overcoming the widespread lack of local, context-dependent evidence and facilitating evidence-based conservation globally. We urge wider disciplines to rigorously reassess the untapped potential of non-English-language science in informing decisions to address other global challenges. Please see the Supporting information files for Alternative Language Abstracts.

The widely held assumption that any important scientific information would be available in English underlies the underuse of non-English-language science across disciplines. However, non-English-language science is expected to bring unique and valuable scientific information, especially in disciplines where the evidence is patchy, and for emergent issues where synthesising available evidence is an urgent challenge. Yet such contribution of non-English-language science to scientific communities and the application of science is rarely quantified. Here we show that non-English-language studies provide crucial evidence for informing global biodiversity conservation. By screening 419,680 peer-reviewed papers in 16 languages, we identified 1,234 non-English-language studies providing evidence on the effectiveness of biodiversity conservation interventions, compared to 4,412 English-language studies identified with the same criteria. Relevant non-English-language studies are being published at an increasing rate, and can expand the geographical (by 12-25%) and taxonomic (by 5-32%) coverage of English-language evidence, especially in biodiverse regions, albeit often based on less robust study designs. Our results show that synthesising non-English-language studies is key to overcoming the widespread lack of local, context-dependent evidence and facilitating evidence-based conservation globally. We urge wider disciplines to rigorously reassess the untapped potential of non-English-language science in informing decisions to address other global challenges.

Consulting the best available evidence is key to successful conservation decision-making. While much scientific evidence on conservation continues to be published in non-English languages, a poor understanding of how non-English language science contributes to conservation decision-making is causing global assessments and studies to practically ignore non-English-language literature. By investigating the use of scientific literature in biodiversity assessment reports across 37 countries/territories, we uncover the established role of non-English-language literature as a major information source locally. On average, non-English-language literature constituted 65% of the references cited, and were recognised as relevant knowledge sources by 75% of report authors. This means that by ignoring non-English-language science, international assessments may overlook important information on local/regional biodiversity. A quarter of the authors acknowledged the struggles of understanding English-language literature. This points to the need to aid the use of English-language literature in domestic decision-making, for example, by providing non-Englishlanguage abstracts or improving/implementing machine translation.

The impact of multiple disturbances on populations could be synergistic or antagonistic via disturbance interaction and are considered to be provoked by alternation of the impact of an ecosystem disturbance due to the effect of a preceding disturbance. The impact of a focal disturbance can also change when a preceding disturbance alters the proportion of individuals in a population exposed to these disturbances (i.e., interaction exposure effects), although this effect has not been addressed to date. Herein, we propose and test interaction exposure effects by elucidating disturbance interactions between canopy gap formation and ungulate grazing. Based on a vegetation and seed bank survey conducted on an island in Hokkaido, northern Japan, we examined whether canopy openness changes the impact of ungulate grazing on the occurrence probability of palatable plant species through the facilitation of germination. Species occurrence in the seed bank significantly decreased with increasing canopy openness under the presence of grazing; however, it slightly increased under the absence of grazing, suggesting that gap creation, which facilitates germination, exposes the seed bank to ungulate grazing. Because disturbances of various types often modify the habitat structure, these proposed disturbance interactions are expected to operate within various ecosystems and taxa. An understanding of the impacts of disturbances on ecosystems is indispensable for comprehending the persistence of populations 1-3. Climate change and increasing pressures from human development have increased disturbance frequency; therefore, it is more likely that ecosystems will be exposed to multiple co-occurring disturbances 4,5 that could severely impact these environments 6-8. Therefore, the interacting effects of multiple disturbances on populations should be understood to help predict the fate of ecosystems 4,9. The population impact of multiple disturbances may be larger or smaller than the sum of the impacts of respective individual disturbances 4,10-14. These cumulative or antagonistic impacts have been attributed to two types of interaction effects: interaction chain effects (linked disturbances in the context of Buma et al. 5) and interaction modification effects 4,9. Within the interaction chain effects, the total impact of disturbances on a population is altered by the indirect effects of a supportive disturbance to the strength and/or extent of main disturbances 15-17 (Fig. 1a), e.g., a typical example of an interaction chain effect would be enhanced severity of a forest fire within a severely blown-down forest 16. Within interaction modification effects, indirect effect(s) of supportive disturbance(s) on main disturbances modifies the per capita impact of the main disturbance 18,19 (Fig. 1b). An example of interaction modification effects is that of savanna fires reducing the resistance of tree trunks to hurricanes, as rapid tree growth following fires results in low wood density 18. Although both interaction chain and modification effec...