Can an Ecoregion Serve as a Seed Transfer Zone? Evidence from a Common Garden Study with Five Native Species


T. N. Kaye, email


Prairie restoration is often limited by the availability of appropriate local plant materials. Use of locally adapted seed is a goal in restoration, yet little information to inform seed transfer guidelines is available for native plant species. We established common gardens of five plants (Eriophyllum lanatum var. leucophyllum, Epilobium densiflorum, Potentilla gracilis var. gracilis, Lupinus polyphyllus var. polyphyllus, and Saxifraga oregana) frequently used in prairie restoration in the Pacific Northwest of North America to determine if populations differed in morphological and phenological traits and whether this variability was structured by geography, climate, or habitat. Ordination techniques were used to summarize the observed variability of multiple traits for each species. Ordination distance was significantly correlated with geographic distance in L. polyphyllus var. polyphyllus, and populations of this species differed significantly among geographic groups within an ecoregion. Little or no spatial structure was detected in the remaining species, despite correlations between ordination scores and monthly temperatures. We suggest that a single seed zone in the Willamette Valley ecoregion may be appropriate for all species examined except L. polyphyllus var. polyphyllus. Ecoregions in general may be useful boundaries for seed transfer zones, especially in regions with relatively little topographical or climatic variation.