Treesearch

A cooperative erosion control project was initiated in 1985 for the North Fork Feather River watershed in California's northern Sierra Nevada due to widespread accelerated erosion. Resulting sedimentation problems have impacted fish, wildlife and livestock resources, and have created operational concerns for hydroelectric facilities located downstream. In response, concerned groups met to develop a restoration plan. A Memorandum of Agreement was signed and a Coordinated Resources Management Planning Committee was formed to facilitate the planning and implementation process. The watershed...

Plant water relations of five obligate riparian species were studied along California's North Fork Kings River. Diurnal stomatal conductance, transpiration, and xylem pressure potentials were measured throughout the 1986 growing season and in mid-season in 1987. Patterns were similar for all species although absolute values varied considerably. Maximum stomatal conductance occurred early in the day and season during favorable environmental conditions and decreased as air temperature and the vapor pressure difference between the leaf and air increased. Maximum transpiration rates occurred...

A series of brush deflectors were installed along an eroding, undercut streambank on Lindo Channel in Chico, California. Pieces of brush were wired to sets of metal fenceposts driven into the bank perpendicular to stream flow and at strategic points upstream. Dormant cuttings of riparian plants were added for revegetation and long-term bank protection. To date (two years deployment), the system has stopped erosion.

A mathematical model is described that relates mature riparian vegetation ecophysiological response to changes in stream level. This model was developed to estimate the physiological response of riparian vegetation to reductions in streamflow. Field data from two sites on the North Fork of the Kings River were used in the model development. The physiological response of three adult white alders and one juvenile red willow were simulated as a function of the meteorological and streamflow conditions. Estimates of predawn leaf water potential, leaf temperature and transpiration rate were...

We investigated the water relations of obligate riparian plants on paired diverted and undiverted reaches on Bishop Creek, Eastern Sierra Nevada. Riparian plants on diverted reaches had reduced stomatal conductance and water potential compared to plants on undiverted reaches in a dry year, but not in a high runoff year. Juvenile plants on diverted reaches had reduced stomatal conductance and lower midday water potentials relative to surrounding mature trees, a trend that was not observed on undiverted reaches. Plants on diverted reaches possessed significantly smaller, thicker leaves and a...

Cut juniper trees (Juniperous osteosperma Hook.) anchored along eroded streambanks proved beneficial in stabilizing 96 percent of the erosion on eight streams evaluated in eastern Oregon over a 14-year-period. Juniper revetment was a successful substitute for costly rock structures on straight or slightly curved banks, but failed when placed on outside curves or when poorly anchored. Water velocities were reduced by 65 percent where juniper revetment was evaluated. Sediment buried tree tips the first and second year after treatment. Juniper revetment should last at least 20 years with...

Innovative techniques for restoring riparian habitats are of little value without a community endorsed plan for their implementation. A flood control district commissioned the Arroyo Management Plan in order to determine how it might provide public access and improve habitat along its current and future channels in a fast-growing area of Northern California. The Plan, prepared by landscape architects involving local communities and agencies, emphasizes the goals and action items that local agencies need to implement in order for the public to regain the use of their streams and arroyos....

Forest Practice Rules under the Oregon Forest Practices Act were modified in 1987 to increase protection of riparian areas adjacent to timber harvest operations. These modifications addressed concerns about water quality protection and retaining trees as sources of large woody debris for future stream channel structure. The rule changes triggered debate about the quantity and quality of trees that should be left in riparian zones. Issues still under discussion include the silvicultural consequences of these rule modifications, and the need to better predict the costs and benefits of the...

One of the most fundamental hydrologic determinations to be made in assessing the probable impacts of flow diversions on riparian vegetation is whether flows are gaining or losing water to groundwater in the reach of interest. Flow measurements on eight streams in the Owens River and Mono Lake basins show that stream- groundwater interactions can produce substantial changes in flow; these changes can vary among streams, along one stream, and in different seasons. Over one stream reach, autumn baseflow increased nearly three-fold from groundwater contributions; in another, summer flow...

Little data concerning autecological needs of desert riparian plant species is available, but the need for revegetation is great. This need results in projects being initiated without knowledge of on site conditions or needs of species planted. Research, superimposed on revegetation projects, can yield data necessary to intelligently implement revegetation projects. Our approach involves: (1) selecting sites on the basis of appropriate preliminary sampling, (2) preparing a planting design after determining distribution of soil/salts on site, (3) planting experimental/control trees at soil...