Tuesday, Aug. 9
Effects of Disease on Aquatic Communities
Organized Oral Session 20, Disease in Ecosystems: Reciprocal Interactions Between Pathogens and Ecosystems 1:30 pm-5:00 pm
Meeting Room 510b, Level 5
Kevin Lafferty, USGS Marine Science Institute, University of Calif., Santa Barbara, Calif.
Though small and often invisible, parasites can change seascapes. Bacterial epidemics of sea urchins can push temperate reefs toward kelp forests. Parasites, which can alter predator-prey interactions by altering prey behavior, comprise a surprising fraction of ecosystem biomass. Infectious diseases may keep common species in balance. Some parasites may even make excellent indicators of ecosystem health because they may reflect abundant and diverse host communities.
Latitudinal Variation in Height and Seed Set of Purple Loosestrife in Eurasia vs. North America: Volunteer Program for Purple Loosestrife Research.
Poster Session 16, Ecology Education 5:00 pm-6:30 pm
Exhibit Hall 220 A-E, Level 2
Beth Middleton, USGS National Wetlands Research Center, Lafayette, La.
Purple loosestrife (Lythrum salicaria), a native of Eurasia, was accidentally introduced to North America in the 1800s. This plant, with its winsomely attractive purple-flower stalk, has established itself so successfully in its new environment that botanists consider it an invasive species – one that may be decreasing the quality of wildlife habitat and altering the function of wetlands. Volunteers around the world are collecting data on seed production, height, and environment to determine how environmental factors limit this species on various continents and to learn how to control this invasive plant in North America. Researchers are looking for additional volunteers. More information is posted on: http://www.nwrc.usgs.gov/special/purplel/index.htm
Ant Communities of the Colorado Plateau and Great Basin: Comparisons of Structure in Space and Time Using Genus and Functional Group Classifications
Poster Session 10, Restoration and Adaptive Management 5:00 pm-6:30 pm
Exhibit Hall 220 A-E, Level 2
Tim Graham, USGS, 2290 West Resource Blvd, Moab, Utah
Small as they are, ants can be important ecosystem drivers because of the ecological functions they perform. Because ants are also influenced by disturbances and environmental stress and can provide important clues to environmental change. USGS scientists collected ants in areas subjected to different disturbance levels in the Grand Staircase-Escalante National Monument, in Canyonlands National Park, and at other sites in Utah and in Oregon. The author will discuss how ants might be used to monitor ecosystem condition.
Wednesday, Aug. 10
Species Invasions Across Spatial Scales: Why the Rich Get Richer
Symposium 10, The Invasion Paradox: Reconciling Biodiversity and Invasion Patterns Across Spatial Scales 8:00 am-11:30 am
Meeting Room 517 A, Level 5
Thomas Stohlgren, USGS Fort Collins Science Center, 2150 Centre Ave Bldg C, Fort Collins, Colo.
Are biologically rich species assemblages difficult to invade? Scientists have reached conflicting conclusions. This presentation argues that high native species richness may not deter the establishment of non-native species from the scale of meters to the globe. Instead, because species richness and habitat heterogeneity typically increase with area, especially in resource-rich habitats, the dominant general pattern in invasion ecology at multiple spatial scales is that invasive species are more likely to establish themselves in species-rich environments. This talk is part of a symposium intended to reconcile disparate views by assembling strong proponents of different research approaches: experimental, observational, theoretical, and modeling, and those who typically conduct research at different spatial scales.
Impact of Fire History on Alien Plant Invasion Following Fire in Mediterranean-climate Shrublands of California
Organized Oral Session 37, Post-fire Conversion of Forest to Non-forest: Do We Need New Theory?
1:30 pm-5:00 pm
Meeting Room 511 C, Level 5
Jon Keeley, USGS, Sequoia Field Station, Three Rivers, Calif.
In contrast to many forest types in the Western U.S., a large portion of California's shrubland landscape has had a much higher fire frequency than likely occurred historically. In many instances this exceeds the threshold of tolerance for native species; each successive fire leaves the landscape increasingly dominated by alien species that may become aggressive invaders. In a study of the alien invasion process during the first five postfire years, the most critical factor influencing the successful establishment of alien plants is the rapid return of the shrub and subshrub canopy. This study suggests that prescription burning is not a viable management practice for controlling alien species on semi-arid landscapes.
The USGS serves the nation by providing reliable scientific information to: describe and understand the Earth; minimize loss of life and property from natural disasters; manage water, biological, energy, and mineral resources; and enhance and protect our quality of life.
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Note to Reporters: Aug. 7-12, you can contact the ESA News Room in Montreal on 514-871-5827. Please note all talks are embargoed until 12:01 am on the day of the talk. All times are local in Montreal, which is EDT.