Treesearch

The fungal pathogen Batrachochytrium dendrobatidis (Bd), which causes the disease chytridiomycosis, has been associated with declines and extinctions of montane amphibians worldwide. To gain insight into factors affecting its distribution and prevalence we focus on the amphibian community of the Klamath Mountains in northwest California. The Cascades frog (Rana cascadae), one of the most common amphibians in these mountains, experienced increased mortality as a result of Bd exposure in laboratory trials and has experienced recent, dramatic declines in other parts of California. We surveyed...

Fires burn large areas in California and around the world annually. California experiences numerous wildland fires that affect the lives of thousands of citizens every year. In 2000 the U.S. census bureau reported that 33.8 million people resided in California. The last census in 2010 showed California population had grown to 37.3 million people. As a consequence of the increase in California’s population, new communities continue to be constructed on the wildland-urban interface. The proximity of people and homes to the wildlands has resulted in the continued efforts to understand fire...

Large wildfire occurrence and burned area are modeled using hydroclimate and landsurface characteristics under a range of future climate and development scenarios. The range of uncertainty for future wildfire regimes is analyzed over two emissions pathways (the Special Report on Emissions Scenarios [SRES] A2 and B1 scenarios); three global climate models (Centre National de Recherches Météorologiques CM3, Geophysical Fluid Dynamics Laboratory CM2.1 and National Center for Atmospheric Research PCM1); three scenarios for future population growth and development footprint; and two thresholds...

Forest thinning and prescribed fire are management strategies used to reduce hazardous fuel loads and catastrophic wildfires in western mixed-conifer forests. We evaluated effects of thinning (Thin) and prescribed fire (Burn), alone and in combination (Thin+Burn), on N transformations and microbial enzyme activities relative to an untreated control (Control) at 1 and 3 yr following treatment in northern California. N mineralization and net nitrification were reduced by Thin and by Burn in year 1, and N mineralization was increased by Thin+Burn in year 3, relative to the Control. In...

Geocaching, an outdoor recreation activity that uses handheld Global Positioning Systems (GPS) to find hidden treasures demarcated on the Internet, emerged in 2000 and has engaged more than 5 million participants in more than 200 countries (www.geocaching.com). Agency responses to geocaching range from collaborative management to exclusion. Effective management, however, depends on knowledge of participants' behaviors and preferences as well as the ability to respond effectively to them. This project profiled geocachers, the benefits they seek in the activity, as well as attitudes toward...

This risk assessment projects the effects of eight forest diseases under two climate-change scenarios (warmer and drier, warmer and wetter). Examples are used to describe how various types of forest diseases may respond to environmental changes. Forest diseases discussed in this report include foliar diseases, Phytophthora diseases, stem rusts, canker diseases, dwarf mistletoes, root diseases, and yellow-cedar decline. The likelihood and consequences of increased damage to forests from each disease as a result of climate change are analyzed and assigned a risk value of high, moderate, or...

Sudden Oak Death (SOD) disease caused by Phytophthora ramorum Werres, de Cock & Man in't Veld was first discovered in Oregon forests in July 2001. Since then, an interagency team has been attempting to eradicate the pathogen though a programme of early detection (aerial and ground surveys, stream baiting) and destruction (herbicide treatment, felling and burning) of infected and nearby host plants, which has evolved over time. Post-treatment monitoring has indicated that although the disease has been eliminated from many of the sites and spread of inoculum may have been reduced, the...