Local and regional factors influencing aquatic invertebrate production

Quantifying invertebrate productivity is important because production estimates are fluxes that can be used to link consumers directly to ecosystem processes such as nutrient cycling and organic matter decomposition. Production estimates also reflect energy and materials potentially available to higher trophic levels. Given the myriad roles of invertebrates in freshwater ecosystems, understanding biotic and abiotic controls on their productivity is significant. As the number of aquatic invertebrate production studies increases, patterns of productivity across various spatial scales are emerging. While physical factors such as temperature and hydrology have pervasive influences on individual growth rates and thus productivity, there is increasing evidence that allochthonous detritus availability in streams and even lake bottoms can be a reliable indicator of invertebrate production across large spatial scales. However, tropical streams, where invertebrate production is low despite abundant detrital resources, and arctic streams, where production is high and detrital resources are low, are significant outliers from these patterns. Identifying variables that can be used to predict secondary production at multiple scales will benefit resource managers and further our understanding of relationships between ecosystem structure and function in freshwaters.