Treesearch

Vineyard expansion into California’s oak woodlands is creating an increasingly fragmented and altered landscape for wildlife. This landscape-level study is designed to provide information about the effects of vineyard development and oak habitat retention on oak-associated bird communities in northern coastal California. We have used Geographic Information System (GIS) technology to identify potential study sites in Sonoma County that are hypothesized to be differentially influenced by vineyard development, or "vineyardization." Degree of vineyardization was determined using a 1997 map of...

The island scrub oak is characterized by a shrubby (to 2 meters) or arborescent (to 5 meters or taller) growth form. It is the dominant species of the scrub oak chaparral community on Catalina Island, which occupies approximately 25 percent of the 76 square-mile island, primarily on north-facing slopes. The Santa Catalina Island Conservancy, which owns and manages 88 percent of the island, is actively working to protect, monitor, and restore this unique plant community. This includes investigating the cause of a large-scale oak dieback, monitoring health, growth, and reproduction, reducing...

The USDA Forest Service (FS) and California Department of Forestry and Fire Protection (CDF) are monitoring Sudden Oak Death (SOD) under the umbrella of the larger California Land Cover Mapping and Monitoring Program (LCMMP). The LCMMP is a statewide cooperative effort among the FS and CDF focused on mapping and monitoring California’s vegetation and land cover.

A diverse suite of projects will be depicted demonstrating the value of mapping, monitoring, and modeling the North Coast's changing oak woodland landscape. This applied research uses a geographic information system to better integrate biodiversity research and conservation planning in California's north coast oak woodlands.

The number of woody species succumbing to Sudden Oak Death (SOD) infections and the number of counties where the pathogen has been reported continue to increase. One result is that the hazards related to falling trees and high levels of fuel hazard conditions are also increasing dramatically. The removal of infected, dead and dying trees creates numerous handling and disposal problems. One possible solution is to develop markets for wood products made from SOD infected material that would help defer some of the cost of removing the hazards and reduce the amount going into landfill. The...

Many local conservation policies have attempted to mitigate the loss of oak woodland habitat resulting from conversion to urban or intensive agricultural land uses through tree planting. This paper models the development of blue oak (Quercus douglasii) stand structure attributes over 50 years after planting. The model uses a single tree, distance independent growth model, calibrated to data derived from a blue oak plantation. The results vary based on initial planting density and plantation management intensity. Data on crown cover, basal area, and average tree diameter and height are...

Two restoration trials involving four oak species have been implemented as part of a larger restoration program for Catalina Island. In 1997 the Catalina Island Conservancy began an active program of restoration after 50 years of ranching and farming activities on the island. The restoration program includes removing feral goats and pigs island-wide and converting 80 acres of old hayfields in Middle Canyon to native plant communities. This conversion presented the opportunity to implement experimental restoration trials to test the efficiency and efficacy of a variety of restoration...

Given the key role played by biogenic volatile organic compounds (BVOC) in tropospheric chemistry and regional air quality, it is critical to generate accurate BVOC emission inventories. Because oak species found in California often have high BVOC emission rates, and are often of large stature with corresponding large leaf masses, oaks may be the most important genus of woody plants for BVOC emissions modeling in California airsheds. Accordingly, reference data for leaf mass and leaf area for a stand of native blue oaks were obtained through harvest of 14 trees located in the Sierra Nevada...

The newly discovered Phytophthora ramorum canker disease of oak (Sudden Oak Death Syndrome) threatens millions of acres of California woodlands where coast live oak (Quercus agrifolia), tanoak (Lithocarpus densiflorus), or black oak (Quercus kelloggii) are dominant species. An important step in controlling this disease involves understanding how it is spread. The presence of diseased oaks at all elevations on hillsides and the above-ground nature of the disease suggest wind-blown rain or rain splash as a common mechanism for movement of spores. Although viable spores have yet to be found...

Sudden oak death has emerged as a major threat to the oak forests of California. In oaks and tanoak, this disease complex consists of a previously unreported fungus-like pathogen, Phytophthora ramorum, insects (bark and ambrosia beetles), and a secondary fungus, Hypoxylon thouarsianum. Species monitored in this study were coast live oak (Quercus agrifolia), California black oak (Q. kelloggii), and tanoak (Lithocarpus densiflorus). Disease progression plots were initiated in March 2000 to determine infection and mortality levels, symptomology, and changes in disease status. Plots were...