Non-native vascular flora of the Arctic : Taxonomic richness, distribution and pathways

We present a comprehensive list of non-native vascular plants known from the Arctic, explore their geographic distribution, analyze the extent of naturalization and invasion among 23 subregions of the Arctic, and examine pathways of introductions. The presence of 341 non-native taxa in the Arctic was confirmed, of which 188 are naturalized in at least one of the 23 regions. A small number of taxa (11) are considered invasive; these plants are known from just three regions. In several Arctic regions there are no naturalized non-native taxa recorded and the majority of Arctic regions have a low number of naturalized taxa. Analyses of the non-native vascular plant flora identified two main biogeographic clusters within the Arctic: American and Asiatic. Among all pathways, seed contamination and transport by vehicles have contributed the most to non-native plant introduction in the Arctic.Peer reviewe

Digital Signal Processing Research Program

Contains table of contents for Section 2, an introduction, reports on twenty-two research projects and a list of publications.Sanders, a Lockheed-Martin Corporation Contract BZ4962U.S. Army Research Laboratory Contract DAAL01-96-2-0001U.S. Navy - Office of Naval Research Grant N00014-93-1-0686National Science Foundation Grant MIP 95-02885U.S. Navy - Office of Naval Research Grant N00014-96-1-0930National Defense Science and Engineering FellowshipU.S. Air Force - Office of Scientific Research Grant F49620-96-1-0072U.S. Navy - Office of Naval Research Grant N00014-95-1-0362National Science Foundation Graduate Research FellowshipAT&T Bell Laboratories Graduate Research FellowshipU.S. Army Research Laboratory Contract DAAL01-96-2-0002National Science Foundation Graduate FellowshipU.S. Army Research Laboratory/Advanced Sensors Federated Lab Program Contract DAAL01-96-2-000

Digital Signal Processing Research Program

Contains table of contents for Section 2, an introduction, reports on twenty-one research projects and a list of publications.U.S. Navy - Office of Naval Research Grant N00014-93-1-0686Lockheed Sanders, Inc. Contract P.O. BY5561U.S. Air Force - Office of Scientific Research Grant AFOSR 91-0034National Science Foundation Grant MIP 95-02885U.S. Navy - Office of Naval Research Grant N00014-95-1-0834MIT-WHOI Joint Graduate Program in Oceanographic EngineeringAT&T Laboratories Doctoral Support ProgramDefense Advanced Research Projects Agency/U.S. Navy - Office of Naval Research Grant N00014-89-J-1489Lockheed Sanders/U.S. Navy - Office of Naval Research Grant N00014-91-C-0125U.S. Navy - Office of Naval Research Grant N00014-89-J-1489National Science Foundation Grant MIP 95-02885Defense Advanced Research Projects Agency/U.S. Navy Contract DAAH04-95-1-0473U.S. Navy - Office of Naval Research Grant N00014-91-J-1628University of California/Scripps Institute of Oceanography Contract 1003-73-5

Consequences of Selecting Rambouillet Ewes for Mountain Big Sagebrush (Artemisia tridentata ssp. vaseyana) Dietary Preference

A dense mountain big sagebrush (Artemisia tridentata Nutt. ssp. vaseyana [Rydb] Beetle) canopy suppresses understory vegetation. Rambouillet ewes with high and low dietary preferences for mountain big sagebrush were tested for their ability to reduce the cover of dense stands of sagebrush. Eighty ewes with high and low preferences for mountain big sagebrush were grazed in October on 8 pastures with a 33% shrub cover for 3 years. Even though near infrared reflectance spectroscopy measurements of feces indicated that high-preference ewes consumed up to twice as much mountain big sagebrush than did low- preference ewes (P < 0.005), there was no difference in the reduction of sagebrush canopy between the high- and low- preference ewes (P = 0.46). Indeed, grazing did not reduce mountain big sagebrush more than in the ungrazed pastures. However, ewes with a high preference for mountain big sagebrush consumed more antelope bitterbrush (Purshia tridentata [Pursh] DC.) (P < 0.05) than did low-preference ewes (length reductions of 30 cm and 10 +/- 3.7 cm [mean +/- SE], respectively). In this study, the selection of ewes with a dietary preference for mountain big sagebrush had the unintended consequence of selecting ewes with a dietary preference for antelope bitterbrush. Antelope bitterbrush is a desirable shrub in sagebrush steppe ecosystems, and reductions in antelope bitterbrush as a result of altered livestock preferences will reduce rangeland health. Animals selected with a dietary preference for one plant species must be screened to determine what other plants they will preferentially select to limit potential negative consequences for plant communities and ecosystems.  The Rangeland Ecology & Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform August 2020Legacy DOIs that must be preserved: 10.2458/azu_rangelands_v58i4_seefeld

The United States Sheep Experiment Station: Shedding Light on Rangeland Ecosystems

The Rangelands archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform March 202