Application of r/K selection to macroinvertebrate responses to extreme floods

Abstract

1. Due to climate change, contemporary climate scenarios forecast an increase in extreme weather, which may have considerable impacts on the world's riverine ecosystems. Because the flow regime is a primary determinant of the structure and function of lotic ecosystems, changes in the weather could fundamentally alter these ecosystems through changes in hydrologic disturbance regimes. 2. In this paper, we use the abundance/biomass comparison ( ABC) method, based on r/K selection theory, and event probability distribution to characterise the responses of macroinvertebrates in Taiwan mountain streams to extreme floods. 3. Severe impacts on macroinvertebrates, resulting in a large shift in community structure toward r-selected taxa, usually were observed the year after extreme floods. 4. Macroinvertebrate communities dominated by K-selected taxa had more individuals with traits conferring resistance to flooding disturbance, while those dominated byr-selected taxa had more individuals with traits conferring resilience. 5. This relationship between the changes in flow regime and the ecological response of r-and K-selected taxa may be exploited to understand the potential effects of flood extremes in the future, and to keep decision makers informed about the ecological consequences of climate-mediated changes to hydrological regimes.