Ecological responses of freshwater macroinvertebrates to augmented drought: A literature review and projections

Drought significantly impacts freshwater ecosystems, disrupting all biological levels. In particular, freshwater macroinvertebrates undergo significant changes in taxonomic and functional diversity bioassessments. The effects often synergize with other stressors, such as pollution that drought can exacerbate. Several techniques have been well-developed (traditional) or have the potential (innovative) to address this issue. This review provides a comprehensive description of the impact of drought as a primary stressor on macroinvertebrate diversity. An overview of the research and projections are presented. Three conceptual pillars drive this study: taxonomic-functional responses, simultaneous pressure dynamics, and innovative techniques. Few studies have been conducted on lentic water bodies, arid and semi-arid systems, and on multiple continents. Common research keywords across continents are observed less frequently in experimental than in field studies. Most analyzed studies examine community structure, which is more common in field-based than experimental studies. Agricultural land use effect, urbanization, and invasive species are the stressors most associated with drought. Integrating traditional with advanced/innovative techniques that have hardly been applied makes it challenging to understand ecological responses comprehensively. If innovative techniques are employed to consider the dynamics of multiple stressors and to consistently estimate taxonomic and functional diversity, promising avenues for future research could be uncovered.