Treesearch

Drought has the ability to affect the persistence of small animal populations, especially those tied to aquatic habitats. We studied the response of western pond turtles Actinemys marmorata to California's worst drought on record. From 2009 through 2015 we used telemetry to track movements and assess survival of 19 western pond turtles in a stock pond at the San Joaquin Experimental Range in the western foothills of the Sierra Nevada, in Madera County, California. In 2013 the pond dried in late summer and winter rains were insufficient for pond formation. The pond remained dry through the...

The California spotted owl (Strix occidentalis occidentalis) is a species of conservation concern owing to threats to its habitat and populations. Verner et al. (1992) first assessed the status of the California spotted owl "The California Spotted Owl: A technical Assessment of it’s current status" (CASPO) and identified four factors as either threats or potential threats to the viability of California spotted owl populations: (1) timber harvest and forest management, (2) wildfire, (3) development of gaps in owl distribution across the Sierra Nevada, and (4) human population growth and...

Spotted owl populations found in southern and central coastal California have received much less attention than those inhabiting the Sierra Nevada because of economic (effect of habitat conservation measures on timber harvest) and social issues (community stability and desire for naturally functioning ecosystems). Yet there has been continued concern over the status of owl populations in this region since the first technical assessment of the California spotted owl "The California Spotted Owl: A Technical Assessment of Its Current Status" (CASPO) in 1992 (Eliason and Loe 2011,2 LaHaye and...

In this chapter, we synthesize the information presented in the preceding chapters of this assessment of the California spotted owl (Strix occidentalis occidentalis) and provide a scientific appraisal of its implications for forest management and owl conservation. We focus on the key scientific findings since the 1992 California spotted owl technical assessment (CASPO) (Verner et. al. 1992) and discuss priorities for future research that could enhance the successful conservation of California spotted owls and their habitat. Throughout this chapter, we acknowledge when uncertainty limits...

The purpose of this work is to estimate willingness to pay (WTP) for minority (African-American and Hispanic) homeowners in Florida for private and public wildfire risk-reduction programs and also to test for differences in response between the two groups. A random parameter logit and latent class model allowed us to determine if there is a difference in wildfire mitigation program preferences, whether WTP is higher for public or private actions for wildfire risk reduction, and whether households with personal experience and who perceive that they live in higher-risk areas have significantl...

Rainfall interception research in forest ecosystems usually focuses on interception by either tree crown or leaf litter, although the 2 components interact when rainfall occurs. A process-based study was conducted to jointly measure rainfall interception by crown and litter and the interaction between the 2 interception processes for 4 tree species (Platycladus orientalis and Pinus tabulaeformis represented needle-leaf species, and Quercus variabilis and Acer truncatum represented broadleaf species) at 3 simulated rainfall intensities (10, 50, and 100 mm hr−1). Results indicated that (a)...

Urban forests can be an effective strategy for managing stormwater. The soil that supports tree growth acts like a reservoir that reduces runoff. The tree crown intercepts rainfall on leaves and stems and its evaporation reduces water reaching the ground below. Until now surface storage capacities have been studied only for forest trees. Based on forest research, green infrastructure accounting tools have assumed a storage depth of one millimeter, regardless of species. We used a rainfall simulator and branch cuttings of 20 tree species in Davis, CA to measure the depth of surface storage...

Most of the California spotted owl’s (Strix occidentalis occidentalis) habitat is concentrated in mid-elevation forests of the Sierra Nevada (see chapter 9 for a discussion of southern California spotted owls and their habitat), which are made up primarily of ponderosa pine (Pinus ponderosa Lawson & C. Lawson), mixed-conifer, white fir (Abies concolor (Gord. & Glend.) Lindl. ex Hildebr.), and mixed-evergreen forest types. These forests have undergone substantial change since the arrival of Europeans and are projected to dynamically respond to ongoing factors affecting ecosystem conditions....

Mapping and mapped data have always been critical to public land managers and researchers for identifying and characterizing wildlife habitat across scales, monitoring species and habitat change, and predicting and planning future scenarios. Maps and mapping protocols are often incorporated into wildlife and habitat management plans, as is the case with the California spotted owl (Strix occidentalis occidentalis), a subspecies of management concern. Current spotted owl managers on all Sierra Nevada national forests use canopy cover and tree size guidelines designed to provide habitat for...

Following Verner et al.’s (1992) technical assessment of the California spotted owl (CASPO), we divided the range of the California spotted owl (Strix occidentalis occidentalis) into two major physiographic provinces: the Sierra Nevada and the mountains of southern California (Tehachapi Pass was the demarcation between the regions). Verner et al. (1992) noted that these provinces are geographically distinct and that movement of owls between them is probably rare, which remains true today (see "Population and Conservation Genetics of California Spotted Owls" section below). The California...