Human modification of vegetative cover can potentially change the size and timing of peak flows. However, on the Smith River, the extent that changes in vegetation have influenced stream flow is not well studied. Future vegetative cover will be most affected by:

• logging on public lands
• logging on private lands
• occurrence of fire.

Logging on public lands is greatly influenced by the Smith River National Recreation Area Act. This legislation designates one section of the NRA as a "timber management area" and specifies that timber production should apply uneven-aged management and long rotations. The legislation also states that timber harvests must also maintain "biological and ecological integrity." In several other areas of the NRA, timber harvests are allowed within existing plantations when compatible with other values, especially scenic values. Except in special circumstances, timber harvest is prohibited in streamside protection zones which generally extend one quarter mile from larger streams and 300 feet from smaller streams. Limited timber harvests are allowed in many areas when necessary for ecological reasons, such as reducing fire hazard (Smith River NRA Act 1990). Over decades, reduced logging on the National Recreation Area will tend to increase the amount of the watershed that is densely forested.

On private lands, the rate of timber harvest will depend largely on unpredictable economic and political factors. Vegetation change due to fire is even less predictable. It is probable that private timber lands near the coast will burn less frequently than public lands which occupy drier hotter inland areas. Prescribed burning programs on public lands may eventually reduce the possibility of stand-replacing fires. Because of the possibility of severe fire, there is no assurance that vegetation cover will increase either on public lands or private lands. Therefore it is not possible to predict changes in vegetation cover across the landscape and their effect on peak flows and other ecosystem processes.

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