PNW 98 Session - Full AbstractsPNW 98 Session - Full AbstractsPrior to the design and implementation for restoration of a 1.5-acre forested
wetland area in Orenco, Washington County, Oregon, soil and hydrologic
data were collected and analyzed. Data collection was conducted for
a one-year period to assess conditions following clearing of the forested
wetland area. It was suspected that site grading and clearing activities
might have altered the hydrologic conditions of the cleared forested
wetland area. Soil data collection included excavation of soil pits to a
depth of 6.0 feet, to describe soil horizons. Hydrologic data collection
included installing five groundwater monitoring wells and staff gauges
at various locations within the cleared forested wetland area, and
monitoring depth-to-water during the growing season. Data indicate a
complex hydrologic system highly influenced by the soil stratigraphy.
A semi-impermeable clay layer was present at depths between 20 and 30
inches below grade. The clay layer allowed the saturated conditions
necessary for wetland development. Depth-to-water during the growing
season varied according to depth-to-clay layer and weather conditions.
Data collection and interpretation were used to design the restoration plan.
Advanced biology students from a local high school are assisting in the
design and implementation of the cleared forested wetland.