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Invasives: Science & Management of Invasive Species The Problem URSOS Solutions Invasive Species Research URSOS Invasive Species Publications Press Coverage of Our Work Invasive Species Monitoring & Management Planning The URSOS Approach An URSOS invasive species management plan The Problem: Loss of Native Biodiversity to Exotic Invasions The introduction and spread of exotic and otherwise invasive plant species (exotic species are not native to a region or habitat, while invasive species are those that spread rapidly from original points of introduction) poses a considerable threat to many of the world’s remaining terrestrial (land) ecosystems, ranging from grasslands and deserts to forests, and from riparian (streamside) communities to alpine tundra. Often termed "weeds", or "noxious weeds" ("noxious" being a political designation, such as by a state or the federal government, to indicate high potential to spread and cause negative environmental and economic impacts alike), traits that make them "invasive" include tolerance of a wide range of environmental conditions, a tendency to flourish even when subjected to frequent human disturbances ("resistance to human disturbance"), and rapid rates of growth, seed production, and seed dispersal. Impacts of invasive plants include species endangerment, reductions in biodiversity and wildlife habitat, alterations to ecosystem processes such as fire frequency, nutrient cycling, and hydrology, increases in erosion and topsoil loss, alterations to soil microclimate, and reductions in land real estate value, agricultural productivity, and livestock forage capacity. The most severe impacts of invasive species often occur where they alter the disturbance regime, such as by increasing fire frequency. The invasive species problem can often be considered a subset of human impacts such the proliferation of roads and off-road vehicle (ORV) use, poor agricultural and livestock grazing practices, and urbanization. A recent study from Cornell University estimated that the spread of invasive species costs private landowners and governmental agences upwards of $137 billion per year in eradication and control costs, reduced agricultural and forage productivity, and reduced real estate values. URSOS Solutions: Invasive Species Research, Monitoring, and Management Planning URSOS conducts research to address questions critical to understanding how to improve land management to favor native and not invasive exotic species. We also apply our scientific knowledge of "invasion ecology" (the study of the distribution, spread, and management of invasive species) by constructing weed management plans, in which we first diagnose the causes of the problem and then recommend remedies. The treatments that we prescribe may differ depending on the type of ecosystem, the invasive species in question, the environmental impacts of both the problem species and the potential control measures, and the economic needs of our customers. We keep up with the state of the art in invasive species research and management, and are fortunate to maintain a network of peers in universities, agencies, and NGOs (e.g., The Nature Conservancy) who are among the field's most knowledgeable researchers and practitioners. We use our knowledge and network of experts to (1) conduct invasive species research and monitoring and (2) design aggressive invasive species management plans, characterized by persistent monitoring and rapid eradication of new infestations. In the future, we seek to become more involved in efforts to restore native communities that currently suffer from invasion.
Gelbard, J.L.. In Progress. Invaders on the move: roads and off road vehicles as major causes of weed invasions. Chapter in book due out in 2006, Island Press. Gelbard,
J. L. 2003. Grasslands
at a crossroads: protecting and enhancing resilience to climate change.
Pages 13-40 in Hanson L.J., J.L. Biringer, and J.R. Hoffman (editors).
Buying time: a user’s manual for building resistance and resilience
to climate change in natural systems. World Wildlife Fund. Washington
D.C. 242 Pages. Sacramento
Bee article: Weeds at home on our roadsides Invasive Species Monitoring & Management Planning The URSOS Approach: Background and Principles Our invasive species management plans are based on the principle that the only way to truly cure a disease is to address its causes, not just its symptoms. This requires use of an aggressive preventative approach in which (1) the sources of seed introduction are identified and curtailed, and (2) any controllable conditions that allow or accelerate the establishment of invasive species (e.g., human disturbances, fertilization) are reduced or eliminated. It also requires persistent monitoring, using a global positioning system (GPS) to mark and map the locations of infestations for future monitoring, and rapid eradication and control measures in response to monitoring results. Prevention: environmental and economic benefits By virtual consensus, invasion ecologists agree that strategies for preventing and slowing the proliferation of invasive species should focus on the causes of invasions (such as seed sources and disturbances that increase vulnerability), not just the infestations themselves. Just as individuals who pay attention to threats posed by an illness only after they have become sick are more likely to suffer more pronounced reductions in personal health, resulting in the need for more expensive medical treatments, land managers who pay attention to threats posed by invasive species only after their lands have become invaded are more likely to suffer more pronounced reductions ecosystem health, resulting in the need for more expensive eradication and control treatments. It is increasingly apparent, moreover, that when it comes to confronting the invasive species problem, an aggressive, prevention-oriented, and adaptive (easy to integrate new information into) approach is favorable not only ecologically, but also economically. A prevention-oriented approach requires stemming the influx of propagules (seeds) via the numerous vectors that managers can control, such as vehicles, livestock, outdoor recreationalists, and those related to international trade and horticulture (it would be virtually impossible to prevent seeds from being introduced via natural vectors such as streams, wind, and native wildlife). This will require persistent monitoring of lands adjacent to roads and trails, and in pastures and other hot-spots of seed introduction (to keep track of the spread of the invasive species in an area and help determine possible causes of spread), as well as rapid eradication of new infestations. In addition, it will require coordination with neighboring landowners to prevent neighboring properties (that may still be infested) from providing seed sources for recolonization. Preventative management also requires minimizing disturbances that increase vulnerability to invasion, especially those caused by livestock, logging, ORVs, road maintenance operations, and outdoor recreationalists. Although the influence of any one of these factors may differ depending on such factors as soil fertility and moisture, and the ecosystem or plant community type in question, all that are affecting the vulnerability of a site to invasion should be addressed. An aggressive "do it now" approach Attention to detail, as well as political willpower, will make or break invasive species management efforts. For example, reseeding of competitive native species may only succeed during exceptionally wet years. The responsiveness of "adaptive" management, especially the efficiency with which monitoring results are translated into on-the-ground management changes (to stem any detected spread), will prove critical to success. For scientific references and further details concerning the above information, please check out the World Wildlife Fund Book Chapter by Gelbard (2003). Example of an URSOS invasive species management plan (following The Nature Conservancy's Site Weed Management Plan Template): Gelbard, J. L. 2003. Weed Management Plan for the UC Davis McLaughlin Reserve. UC Davis Natural Reserve System. October, 2003. |
Invasive Species Research & Management Photos Invasive species such as yellow starthistle (Centaurea solstitialis) are spread predominantly along roads and thrive in highly disturbed habitats. Read Popular Press Article about our invasive species research and outreach.  Roads act as corridors for the spread of invasive weeds.  Poor livestock grazing practices both allow exotic seeds to be dispersed and create disturbances that allow introduced weeds to thrive.  Monitoring is a major key to preventing the spread of invasive species, for it allows early detection and rapid eradication of new infestations.  We encourage you to pull weeds such as spotted knapweed (above) from along hiking trails. This is especially important where you find only a few individuals of a weed, allowing the infestation to be eliminated before it can spread. Such hand pulling kept yellow starthistle under control in California's Yosemite Valley for years!  With careful planning, weeds can be eradicated and native communities such as this grassland can be restored. |