At valley and local scales, natural riparian vegetation and the stream corridor protect the integrity of freshwaters (Richardson et al. 2010b). The riparian area provides shade and thermal moderation, bank integrity, organic matter inputs, nutrient storage and transformation, supplies of terrestrial invertebrates, large and small wood, nutrient sequestration, and important habitat for freshwater and many terrestrial species (Naiman and Décamps 1997; Richardson et al. 2005; Richardson 2008). The environmental basis of freshwater ecosystem productivity depends strongly on inputs from the surrounding terrestrial landscape (Richardson et al. 2010a). Leaf litter from vegetation surrounding streams and lakes is one of the most important sources of energy to freshwaters (e.g., Fisher and Likens 1973; Richardson 1991; Wallace et al.
1999), and terrestrial invertebrates falling from riparian areas contribute
about half of the diet of many commercially and recreationally
important stream fishes (e.g., Wipfli 1997). Small streams
may transport invertebrates and organic matter into larger, fishbearing
streams and contribute most of the energy to support the
growth of fishes in those streams (e.g., Wipfli et al. 2007; Wipfli
and Baxter 2010). Lakes and wetlands also receive most of their
energy from organic matter inputs, largely in the form of particulate
and dissolved organic carbon from the surrounding landscape
(Carpenter et al. 2005).