Great Ideas in Riverine Ecology Linear to Landscapes FISH 7380; Dr. E. Irwin

Geology and climate (present and historical) River Morphology Hydrology Sediment transport Nutrient/elemental availability Basin flora and fauna Terrestrial communities Systems created by water running downhill depend on: Carbon/solar input Patterns of flows = community function 4) spiraling and retention 5) connectedness 6) biotic/abiotic controls Human interference 1) stream classification 2) longitudinal processes 3) Riparian-river interactions Land use heterotrophy biota Trophic structure Habitat structure

Classification Streams can be classified Allows managers and scientists to organize river systems Conceptual and regional approaches Climate and geology, but vegetation important also NA-Ecosystem approach (broad scale) Climate, physiography and vegetation

Hierarchical classification Spatially nested levels of resolution Problem— relatively distinct boundaries

Stream Order Strahler (1952) and modified by Horton (1945) Variation from headwaters to mouth Ordering gives a measure of position Others-link magnitude, d-link

Longitudinal Zonation

River Continuum Concept Downstream transfers of energy and matter Invertebrate functional groups US—DS in lowland rivers=lateral exchanges and vertical fluxes

River-Riparian Interactions Allochtonous inputs, LWD Flood-pulse concept Annual floods drive organic matter and nutrient input in large floodplain rivers.

Lateral and vertical bounds revisited

Longitudinal, lateral and vertical fluxes

Spiraling and Retention

Connectedness

Disturbance Other abiotic controls Biotic? Limiting resources Abiotic and Biotic Control

Disturbance-structures stream communities High/low flows Especially in headwaters

Pressure Points Interference: how management can mess things up. Discontinuity- Serial Faunal