Ebey's Landing National Historical Reserve vegetation inventory and mapping project

Copass, Catharine; Ramm-Granberg, Tynan

This report presents a vegetation classification, inventory, and map of plant associations found across the entirety of Ebey’s Landing National Historical Reserve. The classification, keys, and descriptions in the report will allow Reserve stakeholders to consistently identify and distinguish vegetation types within the Reserve and inform management decisions. The vegetation maps provided within the report represent the best available maps of existing (not potential) vegetation for the Reserve. During the vegetation classification of Ebey’s Landing National Historical Reserve, we inventoried 51 alliances or associations, of which 31% were forests and woodland communities, 57% were shrublands and herbaceous types, and 10 % were agricultural or developed types. The long and varied history of human land use at Ebey’s Landing National Historical Reserve has resulted in ruderal classification for nearly one third of the forest, woodland, shrubland, and herbaceous types. Ruderal types are dominated by novel combinations of native and non-native vegetation due to human disturbance. The Reserve is home to seventeen plant associations considered critically imperiled or imperiled in the state of Washington, or globally. These communities include dry forests or woodlands restricted to a limited range in the rain shadow zone of the Puget Sound basin, remnant and restoration prairie types, rare wetlands, a salt marsh type, and a fen. Each vegetation type within the Ebey’s Landing National Historical Reserve was mapped to at least the alliance level and most were mapped at the association level of the National Vegetation Classification system. The map shows that the Reserve is 59% cultural or unvegetated, roughly split between the pasture and agricultural fields map class and the combined high and low density housing map classes. A third of the Reserve is forest and woodlands. Two forest types, Pseudotsuga menziesii - Tsuga heterophylla / Rhododendron macrophyllum - Vaccinium ovatum - Gaultheria shallon Forest and Pseudotsuga menziesii - Tsuga heterophylla / Gaultheria shallon - Holodiscus discolor Forest contribute a majority of the forest cover. The Symphoricarpos albus - Rosa nutkana is the largest shrubland association, with much of that cover in the form of hedgerows. The largest non-ruderal herbaceous type is the Distichlis spicata - (Salicornia virginica) Herbaceous Vegetation Association, found ringing several of the lagoons and lakes. Map accuracy assessment focused on the natural vegetation types. Overall map accuracy is 81.1%. The vegetation inventory and map provide contemporary tools for the multiple stakeholders in the Reserve. They can be used to inform a wide variety of management decisions, as well as interpret for residents of and visitors to the Reserve both the unbroken continuity and the change in the vegetation and land cover of this unique rural landscape.

Ebey's Landing National Historical Reserve vegetation inventory and mapping project

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