Table 1 The main processes by which riparian features support aquatic features defined.

Erosion

Soil gradually wearing away by wind, water or gravity. When erosion is occurring within a natural range of variation, it controls sedimentation and siltation; supporting aquatic attributes such as aquatic vegetation and interstitial spaces, and channel forming processes at the longitudinal scale (i.e., meandering of a stream)

Filtration

Removing matter or sound from air or water. When filtration is occurring within a natural range of variation it prevents contaminants, excess sediments, and excess nutrients in surface and subsurface water in the riparian zone from entering a waterbody

Infiltration

Surface water entering the soil. When infiltration is occurring within a natural range of variation it maintains natural water levels and flow in the aquatic habitat by maintaining natural levels of surface and sub-surface water entering the waterbody

Shading

Adjusting the amount of light admitted onto a surface. When shading is occurring within a natural range of variation it provides cover and maintains the photic environment and water temperature in the aquatic habitat and maintains natural variation in the temperature of water entering the aquatic habitat

Subsidization

Transferring energy, food, and structural components from the terrestrial habitat to the aquatic habitat. When subsidization is occurring within a natural range of variation it provides provide food for fishes (e.g., terrestrial insects), mussels (e.g., organic matter), and their aquatic prey (e.g., nutrients and organic matter); subsidization of wood and other structural components provides cover and maintains natural flow dynamics in the aquatic habitat