WERC Highlights -- May 2006

Invasive Grasses/Fire Cycle in the Mojave Desert: USGS scientist Matt Brooks of the Western Ecological Research Center has been invited to give the plenary talk at the Fourteenth Wildland Shrub Symposium, to be held June 6-8, 2006, at Southern Utah University, in Cedar City, UT. His presentation is titled “Is the Mojave Desert Going the Way of the Great Basin, with Increasing Frequent Fire over Large Areas?” An increase in fire frequency and size in the Mojave Desert since the 1980s has been attributed to increasing fine fuels produced by invasive annual grasses, especially red brome and cheatgrass. The feedback between invasive grasses and fire has led to frequent and extensive fires over broad expanses of the Great Basin, and there is a concern that a similar trend is becoming established in the Mojave Desert. The Great Basin fires have negatively affected habitat for sensitive species such as the sage grouse, pygmy rabbit, and wide array of raptors, in addition to threatening human communities. In the Mojave Desert there are similar concerns, especially for the desert tortoise, since the loss of thermal cover and native forage plants that typically follow fire can significantly affect this species. For more: http://www.suu.edu/scps/confer/wildland/. (Matt Brooks, Henderson, NV, 702-564-4615, matt_brooks@usgs.gov)

USGS Scientist to Speak at Weed Meeting: USGS scientist Peggy Moore of the Western Ecological Research Center was invited to give a presentation at the Invasive Plant Mapping Roundtable on June 5, 2006, at the University of California, Davis. The meeting is sponsored by the California Invasive Plant Council. Moore will detail the approach taken by USGS to inventory, map, and prioritize non-native plant populations for management in Yosemite, Sequoia and Kings Canyon national parks. (Peggy Moore, El Portal, CA, 209-379-1309, peggy_moore@usgs.gov)

Yale Forestry Comes to the Sonoran Desert: On May 25, 2006, USGS researchers Cecil Schwalbe (Southwest Biological Science Center) and Todd Esque (Western Ecological Research Center) will host 45 graduate students, faculty, and international scientists as part of a field course conducted by the Yale School of Forestry. Esque and Schwalbe will explain their research on the relationship between fire and invasive grasses in North American deserts and the effects of those fires on native plants and animals. The group will meet with the USGS scientists near Saguaro National Park East and then visit the park to see the effects of buffelgrass removal there. (Cecil Schwalbe, Tucson, AZ, 520-621-5508 ext 3, cschwalbe@usgs.gov; Todd Esque, Henderson, NV, 702-564-4506, todd_esque@usgs.gov)

Snail’s Parasites Attest to Salt Marsh Health: NOAA’s California Sea Grant recently awarded parasite experts Armand Kuris (University of California, Santa Barbara) and Kevin Lafferty of the USGS Western Ecological Research Center support to collect California horn snails from 30 coastal salt marshes between Marin County and Imperial Beach at the U.S.-Mexico border to establish a baseline snail-trematode count in marshes, particularly those slated for restoration. The scientists have found the common marsh snail to be a “mobile data recorder” that provides the means to reconstruct the food web in an area and assess biodiversity. Horn snails are the hub for more than 20 trematode species, parasitic worms that must sequentially infect certain hosts to complete their life cycle, which typically begins in a snail and ends in a bird, with intermediate hosts variable. Hence, a healthy salt marsh is one in which many kinds of trematode worms can be found, evidence that many kinds of birds and their prey have been present in the marsh. If a certain trematode is missing at a marsh, it could indicate that its hosts are lacking appropriate habitats. By comparing worm statistics before and after a restoration project, the biologists believe that wetlands managers will have a tool for gauging restoration success and its gaps. (Kevin Lafferty, Santa Barbara, CA, 805-893-8778, klafferty@usgs.gov)

Postfire Plant Demography and Functional Types: Out of necessity, resource managers often deal with broad generalizations about plant community structure and function. In the May issue of Ecological Monographs, USGS scientist Jon Keeley and colleagues Melanie Baer-Keeley from the National Park Service and C. J. Fotheringham from the University of California, Los Angeles, investigated the extent to which species-specific rather than broad functional type approaches are required to understand community responses to disturbance. This study used highly detailed demographic data to investigate vegetation recovery during the first five years after fire in southern California chaparral and sage scrub. For more: http://www.werc.usgs.gov/pubbriefs/keeleypbmay2006.html. (Jon Keeley, Three Rivers, CA, 559-565-3170, jon_keeley@usgs.gov) Citation: Keeley, J. E., C. J. Fotheringham, and M. Baer-Keeley. 2006. Demographic patterns of postfire regeneration in mediterranean-climate shrublands of California. Ecological Monographs 76(2):235–255.

Vernal Pools: A Riverside fairy shrimp photo by USGS scientist Chris W. Brown of the Western Ecological Research Center is slated to appear on a Marine Corps Base Camp Pendleton outreach poster about vernal pools. (Chris Brown, San Diego, CA, 619-225-6433, cwbrown@usgs.gov)

Night Lights: The San Diego Union-Tribune highlighted a study on reptiles that was coauthored by USGS scientist Robert N. Fisher, and printed a California glossy snake photo taken by USGS scientist Chris W. Brown, in a May 17, 2006, story on the new book “Ecological Consequences of Artificial Night Lighting”: http://www.signonsandiego.com/uniontrib/20060517/news_1c17snakes.html. (Chris Brown, San Diego, CA, 619-225-6433, cwbrown@usgs.gov)

Landbirds Depend on Salton Sea Too: Salton Sea has become a critical habitat for aquatic and terrestrial fauna alike, especially migrating and wintering birds. In a recently published study, USGS scientists found that landbird species diversity -- both in numbers of species and numbers per species -- was dependent on proximity to the shoreline of Salton Sea. Surveys of landbird diversity in 2001 showed highest numbers in proximity to the southwest shoreline. Patterns of vegetation cover by the dominant plant species at the site were also related to proximity to the sea's edge, indicating a probable correlation between the avian community and vegetation cover. Lowering of the water surface level could cause changes in the distribution and cover of the surrounding vegetation and in turn affect landbird diversity. The publication is now available online at http://www.fs.fed.us/psw/publications/documents/psw_gtr191/Asilomar/pdfs/617-620.pdf. (Mark Mendelsohn, San Diego, CA, 619-225-6428, mmendelsohn@usgs.gov) Citation: Mendelsohn, M.B., W.I. Boarman, and R.N. Fisher. 2005. Diversity patterns in the terrestrial avifauna of the Salton Sea. Pages 617-620 in C.J. Ralph and T.D. Rich (eds). Bird Conservation Implementation and Integration in the Americas: Proceedings of the Third International Partners in Flight Conference, 2002. Gen. Tech. Rep. PSW-GTR-191. Albany, CA: Pacific Southwest Research Station, Forest Service, U.S. Department of Agriculture. Two volumes.

Partnering Up to Debunk Roadrunner Mythology: A presentation on April 25, 2006 by USGS scientist Mark Mendelsohn for the San Diego Partners for Biodiversity helped separate some fact from fiction with regards to Greater Roadrunners in San Diego County, California. After Mark presented aspects of his recently-completed MS thesis research entitled "Occurrence of the Greater Roadrunner (Geococcyx californianus) in fragmented southern California habitat patches" (San Diego State University, 2005), a lively Q&A session followed. There, fellow government- and NGO-biologists learned that roadrunners do not "meep meep!" but instead "coo coo coo coo coo," that roadrunners may actually be more common in areas without roads, and that the best way to find roadrunners may be to broadcast their vocalizations in the field rather than lay down a pile of Acme bird seeds. (Mark Mendelsohn, San Diego, CA, 619-225-6428, mmendelsohn@usgs.gov)

Desert Tortoises: USGS scientist Phil Medica of the Western Ecological Research Center was contacted by the Boulder City View, a weekly newspaper, regarding desert tortoise numbers within the Boulder City Conservation Easement of Clark County, Nevada, and the effectiveness of barrier fences along highways to reduce tortoise mortalities from vehicles. (Phil Medica, Henderson, NV, 702-564-4573, pmedica@usgs.gov)

Invasive Grasses/Fire Cycle in the Mojave Desert: USGS scientist Matt Brooks of the Western Ecological Research Center will give a presentation titled “Is a grass/fire cycle establishing in the Mojave Desert?” at the Ecology and Management of Red Bromegrass Fine Fuels in Southwest Deserts symposium, to be held May 16-17, 2006, at Arizona State University Polytechnic, in Mesa, AZ. An increase in fire frequency and size in the Mojave Desert since the 1980s has been attributed to increasing fine fuels produced by invasive annual grasses, especially red brome and cheatgrass. In the Mojave Desert there are concerns about the establishment of an invasive grass/fire cycle, especially for the desert tortoise, since the loss of thermal cover and native forage plants that typically follow fire can significantly affect this species. (Matt Brooks, Henderson, NV, 702-564-4615, matt_brooks@usgs.gov)

Southern California Aquatic Wildlife: USGS scientist Cynthia Hitchcock of the Western Ecological Research Center will give an update on the status of remaining populations of mountain yellow-legged frogs in southern California at the Southern California Academy of Sciences annual meeting, to be held May 12-13, 2006, at the Drescher Graduate Campus of Pepperdine University, in Malibu, CA. A poster by the multi-agency Southern California Native Freshwater Fauna Working Group will highlight ongoing efforts to better understand the effects of wildfire/flooding on the Santa Ana speckled dace. For more: http://scas.jsd.claremont.edu/annual/annual.html. The meeting will be held in conjunction with SETAC (Society of Environmental toxicology and Chemistry) and with CAERS (California Estuarine Research Society), which will both sponsor symposia. (Robert N. Fisher, San Diego, CA, 619-225-6422, rfisher@usgs.gov)

Fire as an Ecosystem Process: On May 3, 2006, USGS scientist Jon Keeley of the Western Ecological Research Center will give the 26th Annual William P. Thompson Memorial Lecture at Northern Arizona University, in Flagstaff. William Thompson was a faculty member in the NAU Forestry department from 1961 to 1974, and this annual lecture is supported by a permanent endowment established to advance forestry education. Keeley’s presentation is titled “Fire as an Ecosystem Process: Past, Present and Future.” (Jon Keeley, Three Rivers, CA, 559-565-3170, jon_keeley@usgs.gov)

Forest Reproduction and Climate: USGS scientists Phil van Mantgem, Nate Stephenson, and Jon Keeley of the Western Ecological Research Center recently published an article in Forest Ecology and Management about forest reproduction in relation to climate. Using elevation as a proxy for climate, the authors used permanent plot data from Sequoia and Yosemite National Parks to demonstrate that seedling densities and demographic rates (establishment, growth, and death) of forest tree species declined sharply with increasing elevation. Surprisingly, seed production was not related to elevation. These data provide valuable baseline information to compare against anticipated climatic changes. For more: http://www.werc.usgs.gov/pubbriefs/vanmantgempbapr2006.html. (Phil van Mantgem, Three Rivers, CA, 559-565-3179, pvanmantgem@usgs.gov) Citation: van Mantgem, P. J., N. L. Stephenson, and J. E. Keeley. 2006. Forest reproduction along a climatic gradient in the Sierra Nevada, California. Forest Ecology and Management 225:391-399.

Fuel Breaks Aid Spread of Nonnative Invasive Plants: Federal initiatives, including the National Fire Plan and the Healthy Forests Restoration Act of 2003 (HR 1904), have extended the scope of pre-fire fuel manipulations to include a wide range of vegetation types and treatment prescriptions, and have dramatically increased the number of acres treated to reduce fuels. In the April issue of Ecological Applications, USGS scientist Jon Keeley and USFS colleagues Kyle Merriam and Jan Beyers report that an unintended result of these fuel modification programs can be the introduction and spread of nonnative invasive plant species. Their study focused on forests and shrublands throughout California and included fuel breaks in coastal scrub, chaparral, oak woodland, and coniferous forest vegetation types. Their study also included a range of construction methods, maintenance regimes, and fire histories. The scientists reported that cover and diversity of nonnative species were significantly higher on fuel breaks than in surrounding wildland areas. Elevation and vegetation type had a marked influence on nonnative plant abundance, and the problem was most pronounced in the lower foothill chaparral and coastal scrub. In addition, wildland areas adjacent to fuel breaks were more likely to be invaded by nonnative species when the wildlands had been subject to grazing or recurrent fires. For more: http://www.werc.usgs.gov/pubbriefs/keeleypbapr2006.html. (Jon Keeley, Three Rivers, CA, 559-565-3170, jon_keeley@usgs.gov) Citation: Merriam, K. E., J. E. Keeley and J. L. Beyers. 2006. Fuel breaks affect nonnative species abundance in Californian plant communities. Ecological Applications 16:515–527.

Fire Management Impacts on Invasive Plants: Fire management practices have had diverse impacts on alien plant invasions in the western United States, as outlined in a recent paper by USGS scientist Jon Keeley of the Western Ecological Research Center. In the April issue of Conservation Biology, Keeley considers the impact of six fire management practices on alien invasions: fire suppression, forest fuel reduction, prescription burning in crown fire ecosystems, fuel breaks, targeting noxious aliens, and postfire rehabilitation. For more: http://www.werc.usgs.gov/pubbriefs/keeleypbapr2006b.html. (Jon Keeley, Three Rivers, CA, 559-565-3170, jon_keeley@usgs.gov) Citation: Keeley, J. E. 2006. Fire management impacts on invasive plants in the Western United States. Conservation Biology 20:375–384.

Factors Determining Species Diversity in Postfire California Chaparral and Sage Scrub: Diversity of mediterranean-type ecosystems is of interest because these are hotspots of species richness and diversity is typically highest in the early postfire years in California shrublands. However, as shown in recent research by USGS scientists Jon Keeley and James Grace and colleagues, published in the journals Diversity and Distributions and Ecological Applications, this generalization is overly simplistic and diversity is determined by a complex of temporal and spatial effects. For more: http://www.werc.usgs.gov/pubbriefs/keeleypbapr2006c.html. (Jon Keeley, Three Rivers, CA, 559-565-3170, jon_keeley@usgs.gov) Citations: Keeley, J. E., C. J. Fotheringham, and M. Baer-Keeley. 2005. Factors affecting plant diversity during postfire recovery and succession of mediterranean-climate shrublands in California, USA. Diversity and Distributions 11:525–537. Grace, J. B., and J. E. Keeley. 2006. A structural equation model analysis of postfire plant diversity in California shrublands. Ecological Applications 16:503-514.