Treesearch

Updated version available at: https://www.fs.usda.gov/treesearch/pubs/57247

The i-Tree Streets (formerly STRATUM) computer program quantifies municipal forest structure, function, and value using tree growth and geographic data from sixteen U.S. reference cities, one for each of sixteen climate zones. Selecting the reference city that best matches a subject city is problematic when the subject city is outside the U.S., lays on the border between two climate zones, has a different climate, or tree species composition because of differences in elevation, urban morphology, and environmental quality. A systematic process for selecting the best match is described and...

Phytophthora ramorum is an invasive plant pathogen causing considerable and widespread damage in nurseries, gardens, and natural woodland ecosystems of the United States and Europe, and is classified as a Category 1 pest in Australia. It is of particular interest to Australian plant biosecurity as, like P. cinnamomi; it has the potential to become a major economic and ecological threat in areas with susceptible hosts and conducive climates. Research was undertaken in California to assess pathogenicity of P. ramorum on Australian native plants. Sixty-eight test species within 24 families...

The forests of Marin County were among the first in coastal California to be affected by the Phytophthora ramorum epidemic. Although initially observed in 1994 in tanoaks (Lithocarpus densiflorus) and 1995 in coast live oaks (Quercus agrifolia), it is evident from studies of disease progression that the pathogen was present at least several years prior to the first recorded tree mortality (Rizzo and Garbelotto 2003; McPherson and others 2005). The causal agent had not been identified in March 2000 when we established 20 plots in two Marin County sites, China Camp State Park, (CCSP, coast...

Numerous lines of inquiry have concluded that tanoak (Lithocarpus densiflorus) will continue to experience drastic population declines and may even disappear entirely from redwood (Sequoia sempervirens) forests as a result of the exotic disease sudden oak death (SOD) (Maloney and others 2005, McPherson and others 2005, Meentemeyer and others 2004, Rizzo and others 2005). As the only species that can both compete for canopy space and tolerate the deep shade of redwood understories, tanoak is widespread and abundant in redwood forests, and is an integral component of the structure and...

Many commercial algaecides contain copper compounds as active ingredients. Phytophthora spp. and other oomycetes are known to be sensitive to copper-based fungicides. Therefore, algaecides registered to manage algae in natural waterways and irrigation waters also might be effective for mitigating or even eradicating Phytophthora species, including P. ramorum, in these same waterways. Many of the commercially available algaecides are registered for use in diverse natural and agricultural water environments, and water treated with these products may be used for swimming, fishing, watering...

This panel aimed to discuss the intersection of biology and society; specifically, how we balance competing social and biological concerns in regards to forest pests and land management in general. Four panelists began the discussion: Janice Alexander, Sudden Oak Death Outreach Coordinator for the University of California (U.C.) Cooperative Extension, Marin County and the California Oak Mortality Task Force; Dr. Lynn Huntsinger, rangeland ecologist, U.C. Berkeley; Chris Lee, Sudden Oak Death Coordinator for U.C. Cooperative Extension, Humboldt and Del Norte Counties; and Chuck Striplen,...