Chapter 8 - From Headwaters to Rivers to River Networks: Scaling in Stream Ecology

Abstract

The effect of environmental change on aquatic ecosystems requires a broad scale perspective because of the high degree of connectivity within river networks. This chapter demonstrates the spatial and temporal scaling issues that must be addressed to understand stream ecology at landscape scales. A mathematical framework is proposed that accounts for the heterogeneity of biogeochemical supply and demand throughout river networks as influenced by physical, chemical, and biological characteristics. Considerations for scaling each type of characteristic throughout river networks are discussed. This framework represents a synthesis of stream spiraling theory, connectivity theory, and patch dynamics. Human activities can be represented in the mathematical framework to explore how multiple changes interact to alter broad scale aquatic ecosystem function through changes in biogeochemical supply and demand.