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Riparian Plants: Oregon Ash - Fraxinus latifolia

Return to riparian plant list or the Ecological Tolerances of Riparian Plants page.

Oregon ash can be found in mixed riparian forest plant communities, but it is typically a non-dominant species. Oregon ash is most commonly found as medium sized trees in mixed riparian forests dominated by oaks, at moderate elevations relative to the water table. Under a closed canopy and at lower elevations relative to the water table where flooding and physical battering is more frequent, Oregon ash remains more shrub-like. Oregon ash has shallow roots that do not have to reach the water table. It is tolerant of long duration flooding and periods of drought. Oregon ash most commonly grows in loamy soils.

Oregon Ash will reach 9m in about 20 years, and can grow up to 23m. The trunks can reach just under a meter in diameter, and the smooth bark in young trees and shrubs will eventually grow thick and become deeply furrowed. Oregon Ash provides a low overstory or midstory layer in riparian forests, which provides additional cover and nesting locations for riparian wildlife. The seeds and leaves are eaten by birds and mammals, and the leaves provide a good source of insects.

For more information about the ecological tolerances and structure of riparian plants, see Gaines 1977, Conard and others 1977, Holstein 1984, Sacchi and Price 1988, Faber and Holland 1996, Cooper and others 1999, Vaghti 2003, Fremier and Talley 2009, and Vaghti and others 2009.

Oregon Ash dimensions

Oregon Ash

Young Oregon Ash in winter

Young Oregon Ash in winter