WERC Highlights -- March 2005

Reducing Fire Hazard: Scientist Jon Keeley of the USGS Western Ecological Research Center was quoted in a March 30 article in the San Bernardino Sun on the use of prescribed burning to create defensible space for fire fighters around urban areas and in forests: http://www.sbsun.com/Stories/0,1413,208~12588~2790534,00.html. (Jon Keeley, Three Rivers, CA, 559-565-3170, jon_keeley@usgs.gov)

Foxes in Aleutians: News stories about a recent study on the effects of introduced artic foxes on Aleutian island life, published in the journal Science by a group of authors that includes scientist Jim Estes of the USGS Western Ecological Research Center, have appeared in several newspapers including the New York Times (March 29), Washington Post (March 28), and Newsday (March 24): http://www.nytimes.com/2005/03/29/science/earth/29fox.html http://www.washingtonpost.com/wp-dyn/articles/A5213-2005Mar27.html http://www.newsday.com/news/health/ny-hsfox0325,0,2736241.story?coll=ny-top-headlines (Jim Estes, Santa Cruz, CA, 831-459-2820, jim_estes@usgs.gov)

Introduced Predators Transform Subarctic Islands from Grassland to Tundra: Arctic foxes were first introduced by fur traders to the Aleutian archipelago as an additional fur source beginning in the 18th century and increasingly by trappers following the collapse of the martitime fur trade in the late 19th and early 20th centuries. The foxes severely reduced seabird breeding colonies, initiating an ecosystem-wide trophic cascade that reduced the transport of nutrients from ocean to land, created nutrient-impoverished soils, and transformed a dense grassland, to low-growing tundra, according to a study by researchers from the University of California, Santa Cruz, U.S. Geological Survey, U.S. Fish and Wildlife Service, and University of Montana published in the March 25 issue of the journal Science. Because some islands remained fox-free, the researchers were able to compare fox-infested with fox-free islands and closely examine the effects of the introduced predators. Seabirds transfer nutrients from the ocean to the land by feeding on marine fish and invertebrates and spreading nutrient-rich guano around the islands. The researchers found that the density of breeding seabirds on fox-free islands was two orders of magnitude higher than on fox-infested islands. The resulting difference in nutrient inputs was reflected in soil phosphorus levels that were more than three times higher on fox-free islands. The vegetation on the islands also showed significant differences in nutrient content. Evidence that more ocean-derived nutrients were cycling through the ecosystems of fox-free islands than on fox-infested islands came from analyses of nitrogen isotopes in soil, plant, and animal samples. (Jim Estes, Santa Cruz, CA, 831-459-2820, jim_estes@usgs.gov) Citation: Croll, D. A., J. L. Maron, J. A. Estes, E. M. Danner, and G. V. Byrd. 2005. Introduced predators transform subarctic islands from grassland to tundra. Science 307:1959-1961.

California Flora Database: USGS scientist Jon Keeley of the Western Ecological Research Center has been invited to participate on an advisory board of California botanists and ecologists for a new database project titled Ecological Flora of California: An Online Plant Trait Database (EFCal). The project is a component of the Jepson Flora Project, based at the Jepson Herbarium at UC Berkeley, and will be closely tied to the ongoing revision of The Jepson Manual and the planned publication of a second edition in 2008. The database, which may be ready to launch around the 2008 publication date, will provide comprehensive information on functional and life history traits for California flora and will have powerful search and export capacities to serve research, conservation, restoration, and education communities. Its design is intended to have a high level of compatibility with other similar databases outside California. The advisory board will provide inputs on the design and content of the database to maximize its utility to a broad set of user groups. (Jon Keeley, Three Rivers, CA, 559-565-3170, jon_keeley@usgs.gov)

Salt Pond Restoration: USGS scientist John Takekawa of the Western Ecological Research Center was interviewed on March 24 by the San Francisco Chronicle about monitoring for changes in bird usage during the restoration of San Francisco South Bay salt ponds. USGS is providing science support for the 15,000-acre wetland restoration project by conducting monitoring surveys to document change and facilitate adaptive management. (John Takekawa, Vallejo, CA, 707-562-2000, john_takekawa@usgs.gov)

Effects of Organic Suspended Sediment in Streams in Forested Terrain: USGS research geologist Mary Ann Madej of the Western Ecological Research Center will present her results of sediment studies at the International Association of Hydrological Sciences meeting “Freshwater: Sustainability within Uncertainty,” which will be held in Foz do Iguaco, Brazil, April 3-8, 2005. In the past, hydrologists investigating effects of sedimentation on streams from natural events and land use activities have focused on the inorganic fraction of sediment, but Madej will show that in forested terrain, the organic component of suspended sediment can play a major role in both sediment flux and food web dynamics. When organic sediment remains in suspension at the end and between storms, turbidity changes light passing through stream waters, which in turn can affect algal production and alter the invertebrate food base for salmon and other drift-feeding fishes. Additionally, an increase in the amount of suspended organic sediment affects fish directly by making it harder for them to see their prey, leading to reduced feeding efficiency, reduced feeding rate, and depressed growth. The study areas were redwood-dominated systems, but the results may have implications to any heavily forested area, such as in the tropics. For more: http://www.cig.ensmp.fr/~iahs/. (Mary Ann Madej, Arcata, CA, 707-825-5148, mary_ann_madej@usgs.gov)

Endangered Bird Species Update: The California Least Bell's Vireo/Southwestern Willow Flycatcher/Yellow-billed Cuckoo Working Group will meet in Carlsbad, Calif., from 9 a.m. to noon on March 23, 2005. This annual meeting, organized by USGS scientist Barbara Kus of the Western Ecological Research Center, and co-sponsored by USGS, U.S. Fish and Wildlife Service, and California Department of Fish and Game, brings together over 100 researchers, resource managers, and biological consultants from federal, state, local, and non-governmental organizations to discuss the results of field investigations and other issues relevant to the recovery of these endangered species. The program will include presentations on the current status of each species, and the effectiveness of cowbird control in improving reproductive success of least Bell's vireos and southwestern willow flycatchers. (Barbara Kus, San Diego, CA, 858-637-6881, barbara_kus@usgs.gov)

Does Coring Contribute to Tree Mortality? Collecting increment cores is a standard method for measuring tree ages and growth in seasonal environments where annual rings are formed. These data are fundamental for an understanding of historic and contemporary forests and their environments, but there is concern that collecting cores may create a pathway for diseases that could contribute to tree deaths. In a study recently published in the Canadian Journal of Forest Research, USGS scientists Phil van Mantgem and Nate Stephenson used 21 years of annual census data from cored and uncored permanent forest monitoring plots in Sequoia National Park to detect changes in mortality rates for two common species in the Sierra Nevada of California, white fir and red fir. They found no differences in tree death rates up to 12 years following coring. They emphasize, however, that their 12-year post-coring records are short relative to the maximum life spans (more than 300 years) of these species, and these findings may not apply to other species growing in different environments. For more: http://www.werc.usgs.gov/pubbriefs/vanmantgempbmar2005.html. (Phil van Mantgem, Three Rivers, CA, 559-565-3179, pvanmantgem@usgs.gov) Citation: van Mantgem, P. J., and N. L. Stephenson. 2004. Does coring contribute to tree mortality? Canadian Journal of Forest Research 34:2394–2398

Use of Radio Transmitters on Breeding Alcids: Externally attached transmitters may affect breeding alcids, because these birds fly long distances from their nests to feed and must pursue their prey under water. In a radio telemetry study by USGS, Humboldt State University, and the University of California-Davis, scientists investigated effects of transmitters on the reproductive success of breeding Cassin’s auklets in the California Channel Islands. They reported their results in a recent issue of the Wildlife Society Bulletin. Chicks raised by unmarked pairs had faster mass growth rates, faster wing growth rates, greater peak fledging masses, and higher fledging success than chicks raised by radio-marked parents. Fledging success was reduced more when the authors radio-marked the male rather than the female parent. Transmitters did not appear to influence foraging ranges and at-sea distributions, however, since radio-marked Cassin’s auklets foraged in similar areas compared to unmarked auklets that were surveyed concurrently by aircraft at sea. For more: http://www.werc.usgs.gov/pubbriefs/ackermanpbmar2005.html. (Josh Ackerman, Davis, CA, 530-752-0485, jackerman@usgs.gov)

Waterfowl: A USGS study on waterfowl distribution was highlighted in the Feb/March 2005 issue of California Waterfowl, the magazine of the California Waterfowl Association in a story on wetlands accomplishments in the Tulare Basin (see page 44). The study, led by USGS scientist Joe Fleskes of the Western Ecological Research Center, examined wintering waterfowl distribution relative to habitat changes in the Central Valley, California, and documented the continued use and importance of Tulare Basin wetlands for maintaining waterfowl abundance in the southern portion of the valley. (Joe Fleskes, Dixon, CA, 707-678-0682 x628, joe_fleskes@usgs.gov)

Disease: An article featuring sea urchin disease research by USGS scientist Kevin Lafferty of the Western Ecological Research Center appears on page 9 in the January-March 2005 (vol. 6) issue of the journal Conservation in Practice (“Overfishing Implicated in Sea Urchin Epidemics”). For more: http://www.conbio.org/CIP/tocv6n1.cfm. (Kevin Lafferty, Santa Barbara, CA, 805-893-8778, klafferty@usgs.gov)

Tracking Ocean Wanderers: On 12 March, USGS scientist Josh Adams of the Western Ecological Research Center will present a research poster entitled “Migratory seabirds measure pan-Pacific connectivity among west coast National Marine Sanctuaries” at the annual Monterey Bay National Marine Sanctuary Currents Symposium (http://www.mbnms-simon.org/symposium.php) to be held at California State University, Monterey Bay. Adams and colleagues will present new satellite telemetry information linking important migratory seabirds of the California Current (sooty shearwaters and black-footed albatrosses) to key marine habitats within the interconnected network of national marine sanctuaries -- from southern California to the Pacific Northwest. Shearwaters captured off central California were tracked to New Zealand and toward Chile. Preliminary genetic analyses indicate shearwaters mixing in flocks off California included individuals from colonies on both sides of the Pacific. Albatrosses captured within Cordell Bank NMS, north of San Francisco, ranged across the north Pacific, as far as Japan and crossed areas used extensively by long-line fisheries. A companion article involving tracking Sooty Shearwaters also will be published in the MBNMS newsletter, Ecosystem Observations 2005. (Josh Adams, Moss Landing, CA, 831-633-7259, josh_adams@usgs.gov)

Environmental Changes: USGS scientist Nate Stephenson of the Western Ecological Research Center is an invited speaker at the George Wright Society conference in Philadelphia, March 14-18, 2005. Stephenson will use research results to examine the National Park Service's (NPS) natural resources mission in light of pervasive and rapid global changes. Are ongoing environmental changes of such a nature that NPS goals may evolve from restoring and maintaining naturally-functioning ecosystems toward enhancing or maintaining ecosystems that are best able to resist and recover from stresses? (Nate Stephenson, Three Rivers, CA, 559-565-3176, nstephenson@usgs.gov)

Natural Resource Research Awardee: The NPS Pacific West Region has announced winners of the PWR Natural Resource Stewardship and Science Awards for 2004. USGS scientist Gary Fellers of the Western Ecological Research Center is recipient for the category “Natural Resource Research.” Recipients of these awards contributed significantly to improve resource management and knowledge of park resources. (Gary Fellers, Point Reyes, CA, 415-464-5185, gary_fellers@usgs.gov)

Weeding out Buffelgrass in the Sonoran Desert: On March 4, 2005, the state of Arizona listed buffelgrass as a noxious weed under the “prohibited and regulated rules of the noxious weed listing.” Introduced from Africa into south Texas in the 1940s and extensively in Sonora, Mexico since the 1960s, buffelgrass has recently begun to spread vigorously in southern Arizona, invading even remote backcountry areas of national parks and wildlife refuges. The invasive nonnative perennial grass can burn in any season and is capable in most years of producing fuel loads orders of magnitude greater than red brome, a nonnative annual grass that has fueled fires in both the Mojave and Sonoran deserts. A study by USGS scientists at Saguaro National Park is investigating the most cost-effective techniques for removing buffelgrass and restoring the desert’s native vegetation. USGS scientists have also helped launch a buffelgrass eradication and outreach program at the Desert Laboratory on Tumamoc Hill in Tucson, which is operated jointly by the University of Arizona and the U.S. Geological Survey. There scientists estimate that buffelgrass covers 30-40 percent of the 860 acres, and last May a UA buffelgrass program coordinator, Travis Bean, was added to the staff. Last week, UA and USGS representatives of the Desert Laboratory met with state of Arizona officials to request listing of buffelgrass on the state’s noxious weed list; the petition included letters of support from other agencies and organizations. (Todd Esque, Henderson, NV, 702-564-4506, todd_esque@usgs.gov; Julio Betancourt, Tucson, AZ, 520-670-6821 x107, jbetanc@usgs.gov)

Buffelgrass: USGS scientists Todd Esque, Julio Betancourt, and Cecil Schwalbe were interviewed for March 4 stories in the Arizona Daily Star regarding buffelgrass, an invasive nonnative perennial grass that poses an increasing fire threat to the Sonoran Desert ecosystem: http://www.dailystar.com/dailystar/allheadlines/64028.php and http://www.dailystar.com/dailystar/allheadlines/64029.php. (Todd Esque, Henderson, NV, 702-564-4506, todd_esque@usgs.gov; Julio Betancourt, Tucson, AZ, 520-670-6821 x107, jbetanc@usgs.gov; Cecil Schwalbe, Tucson, AZ, 520-621-5508; cschwalbe@usgs.gov)