Great Basin Naturalist Memoirs


Biogeographical considerations are important in the management of western shrublands. Seedings on rangelands have a higher probability of success when tried and tested principles are followed. It is usually best to seed mixtures that include adapted shrubs and herbs. Shrubs generally are well adapted to the environmental extremes of western ranges. Throughout the year, they provide nutrients for herbivores that are only seasonably available in herbs.

Section Tridentatae of Artemisia is endemic to western North America and distinct from the analogous Eurasian section (or subgenus) Seriphidium. The groups have separate, distinguishable centers of diversity; the two groups seem to be connected in the geologic past by way of the more primitive subgenus Artemisia. Preliminary karyotypic evidence suggests different but advanced karyotypes for both groups; chemotaxonomic and morphological data indicate differences in the groups. The Tridentatae likely evolved in North America during late Tertiary or early Quaternary times under the stimulus of cycles of aridity.

The Tridentatae (sagebrushes) are morphologically variable. Different accessions are differentially adapted. Management practices for various taxa should take into consideration the individual taxon's characteristics. Effort should be made to seed adapted taxa and accessions. Sagebrush management requires maintenance, seeding, or thinning, depending upon the circumstances.