Quantitative synthesis of the effects of drought on community composition and species interactions in terrestrial ecosystems

Droughts, increasingly frequent under human-driven climate change, are expected to intensify globally. Both pulsed and prolonged droughts can have pronounced effects on organismal survival and population dynamics, potentially altering terrestrial communities and ecosystems. Understanding the impacts of drought on communities is important to make predictions and mitigate these impacts. Here, we conducted two meta-analyses that evaluate two components of communities: community composition and species interactions, revealing overall negative effects of drought in both analyses. In particular, we found negative impacts on the richness of species, and plant and arthropod community composition, and predation and decomposition were more likely to be negatively impacted. Additionally, we found differences in the effect of droughts in different biomes, with community composition mainly impacted in grasslands and boreal forests, whereas species interaction was negatively affected in forests. Our meta-analyses highlight the potential for drought to disrupt ecological communities on a global scale. These findings underscore the importance of monitoring drought effects in terrestrial ecosystems, particularly in regions of high risk.