Urbanizing Flora of Portland, Oregon, 1806-2008.

Abstract

This is an annotated catalog of the vascular flora of Portland and vicinity. It contains 1,553 taxa in 126 families, and compares the historical flora with changes that have occurred since 1925. Sources included additional publications, the herbarium record, and the botanical observations of the authors and contributors.

The vascular flora of the Portland-Vancouver area is documented by herbarium specimens and publications dating back to 1806. Urbanization has had inevitable and predictable effects on the region's vegetation. Wetlands have declined locally by 97 percent, coniferous forest by 92 percent, prairie and savanna by 90 percent, riparian and wetland forest by 58 percent, and oak communities of any sort by 40 percent. Open water features declined 49 percent. Old literature and specimens document the floristic composition of some of these vanished habitats.