Removal of two high-head dams on the Elwha River in Olympic National Park, WA will expose 276 ha of barren soil in the de-watered reservoirs. Preventing the establishment of invasive exotic plants is the highest management priority for the reservoirs. We propose to facilitate achieving this goal by updating a past survey for exotic plants then spatially modeling the spread from known sources and identifying unexplored potential sources of priority species using gravity models. MORE 
Managers at CHIS require a sampling protocol to track population abundance as numbers of both deer and elk approach zero as mandated by a court-sanctioned settlement agreement. We propose to stratify Santa Rosa Island on the basis of vegetative features likely to influence the detectability of deer and elk and to identify sampling units (SUs) within each stratum covering the entire island. We will conduct aerial counts from a helicopter and road-based line-transect counts of each species within each count unit in December 2007 and 2008. MORE 
Many National Parks have free-roaming cats. The Parks are responsible for removing the cats to protect native species from predation, competition, and diseases. However, their cat control efforts are hindered by native mammals (e.g. foxes, skunks, raccoons, and opossums) attracted to the bait that is used to trap cats and therefore they end up being trapped instead of the cats. The native animals not only, in general, occur in greater densities in the Parks than cats but, unlike cats, they rely on olfactory cues that can detect the bait from greater distances. Therefore the native mammals are more likely to be caught in the traps than the target species. MORE 
The South Florida pine rocklands are a globally endangered ecosystem and only less than ten percent of the original habitat remains. Controlling exotic plants, especially Schinus and reestablishing pine trees are critical for restoring pine rocklands. The proposed research will determine effects of pine trees (natives and replanted) and exotic plants on changes of soil properties.
In Everglades National Park (ENP), at least 12 species of non-indigenous (NI) fishes are presently established, but little is known about their potential impact on native biota. We also know little about how interactions among the NI species may affect their relative invasiveness and impact. The jewel cichlid (Hemichromis letourneauxi) is a highly aggressive omnivore, whose relative abundance and invaded range continues to increase since its first appearance in ENP in 2002. Data collected in this study will be used to assess the potential effects of H. letourneauxi throughout the greater Everglades ecosystem, and determine whether these effects may be influenced by the presence of previously established NI fishes. Insights from this study may have broad implications for the management of aquatic habitats faced with repeated introductions of NI fishes. MORE 
U.S. Department of the Interior |
U.S. Geological Survey
URL: http://www.fort.usgs.gov/brdscience/pobs1.aspx?topic=Invasives
Page Contact Information: Paul_Geissler@usgs.gov
