Population-level responses of stream macroinvertebrates to drying can be density-independent or density-dependent

Abstract

The frequency and intensity of droughts and stream drying are likely to increase with climate change, but how freshwater macroinvertebrate populations respond to such disturbances is poorly understood. Theory predicts that stochastic disturbances should generate density-independent mortality, but density dependence is possible if mortality arises indirectly through changes in consumer-resource dynamics, or if mortality is mediated by disturbance refugia. Empirical evidence for density-dependent or density-independent mortality in freshwater invertebrates is scarce, but important to predict how population sizes will alter with changing climate. In a stream mesocosm experiment, we tested wheth..