The overarching question that Scale, Consumers and Lotic Ecosystem Rates (SCALER) will address is: How can small-scale ecological experiments be applied to understand the behavior of entire ecological systems? Funds are provided to address:: 1) How should measures of fundamental properties of streams and effects of animals on those properties be scaled up to predict ecosystem characteristics of stream networks. 2) How do patterns of scaling compare across the wide array of ecological systems (from tundra to tropical forest) that occurs across North American? The SCALER experiment will be done in tropical forest, temperate mountainous forest, prairie, northern boreal evergreen forest, and tundra areas. Streams in each of these five areas will be examined at scales of centimeters to 10?s of meters in small, medium and large streams. Rates of stream metabolism (photosynthesis and respiration) and nutrient uptake will be measured as well as the way these rates respond to animal exclusions (used to mimic loss of animal diversity in streams). These local results will be linked to the scale of watersheds and regions by modeling. Watershed scale predictions will be verified by broader, but less intensive sampling. Mechanistic explanation of how ecological measurements and experiments in streams can be scaled to watersheds will be provided. This scaling will be characterized in each of the five areas across the continent to explore how scaling differs across natural habitats. The knowledge that will be generated by this project is essential to quantify controls on stream ecosystem processes as well as to manage human impacts on entire watersheds. The experimental and modeling results will be relevant to general ecology because few nested, and experimental and theoretically coupled scaling experiments have been undertaken in any environment. Results will inform those involved in conservation, management, and restoration of freshwater resources. Resource managers will gain a quantitative rationale and framework to link local measurements to regional patterns. The highly collaborative team will train six graduate students, five post doctoral students, and mentor three early career faculty members. Additional collaborations will be encouraged to collaborate and perform similar projects at additional sites through workshops related to the objectives and research design.
