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011)8,,2 DRAPf FINAL DRAFT - 12/19/91 LittJe regeneration of cononwood was observed during a 1991 reconnaissance of the area. Based on the relatively uniform size of the trees in the sites near the upper wilderness boundary, regeneration appears to be cyclical. Successful regeneration of cottonwood requires a closely timed sequence of events. High flows must have removed organic material and deposited or exposed a fresh layer of gravel sized and finer sediments just prior to seed drop and the seedbed must remain moist during seedling establishment. Coyote and Bebb willow reproduce by seed and likely require the same sequence of events. Other factors which conuibute to successful regeneration include the health of the parent tree and temperature and moisture conditions during flowering, pollination, seeding, sprouting, and seedling growth. These factors can be affected by the long and shan-term pattern of stream.tlow. All ecosystems are disturbed from time to time and have developed under a certain pattern of disturbances. Flooding is one of the main forces of disturbance in riparian ecosystems. Riparian plant species. including alter, willow. and red-osier are adapted to periodic flooding and often benefit from such events (Windell. 1986). Upland plant species which might encroach into riparian areas are not adapted to the dynamic nature of riparian ecosystems and the pattern of streamflow events. They oormally can not survive over the long term in a riparian setting. Modification of the pattern of disOJrbance would affect the ecological processes maintaining the riparian ecosystem. Vegetation influences the adjacent aquatic ecosystem by contributing leaf debris, which serves as a food source to aquatic insects; by moderating water temperatures through the shading provided by overhanging vegetation; by providing habitat for terrestrial insects which fall into the stream and supplement the diet of fish; and by serving as a source of logs and branches that can shape local channel morphology. provide and retain organic matter. and provide overbead cover and shading for fish. The rOOt systems can also stabilize stream banks. debris dams. and gravel bars (Meehan. 1991), River otters were first reintrOduced in the Piedra River in 1979: additional otters were released in 1982. They are a Swe listed endangered species. The released otters have distributed themselves between Navajo Reservoir and Williams Creek Reservoir. Because otters are very elusive and mobile. there are no reliable estimates of toul numbers. Although there have been few confinned sightings of otter within the wilderness. continuing evidence of their presence includes tracks and scat along the stream and signs of their feeding activities. They are carnivores and feed principally on fish and to some extent on other aquatic organisms like insects, crayfish, and snails. Riparian vegetation provides cover and shelter. Streamside vegetation improves the probability of eluding predators. and driftwood piles serve as resting areas and locations for territorial marking. Bald eagles, a Federal and State listed endangered species. have been observed along the river. It is used by eagles as a travel corridor betw~n Navajo and Williams Creek Reservoirs and as a transitory hunting area. The southwestern willow flycatcher and Lewis' woodpecker are riparian dependent species which may be present in the proposed wilderness. Lewis' woodpecker uses cottonwoods for nesting. These two species are of management concern [0 the Division of Wildlife due to habitat loss and potentially low population numbers. Page 7