Why drought?

River Itchen, HampshireWater scarcity and drought are among the most pressing environmental issues of the 21st century. Freshwater ecosystems, already damaged by the overuse of water by growing populations, stand to be further affected by climate change, with widespread shifts in rainfall patterns that are likely to intensify droughts in some regions. Across Europe, the frequency and intensity of droughts has already increased dramatically over the past thirty years. Despite its growing prevalence, research on the ecological impacts of river drought lags far behind that of other stressors (e.g. acid pulses or floods), and has focused on community-level effects (e.g. on invertebrate community composition). By contrast, consequences for the functioning of ecosystems that ultimately provide socioeconomically valuable goods and services e.g. water quality and nutrient processing, are still largely unknown.