Treesearch

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...

Light-level geolocators, miniature devices used for tracking avian migration over the full annual cycle, are being widely deployed on small migratory passerines. However, the effects of carrying geolocators on the breeding biology of songbirds are unclear, and variable species- and guild-specific conclusions have been drawn regarding their effects on return rates (apparent annual survival). In particular, there is a lack of published information on the effects of geolocators on Nearctic–Neotropical migrant warblers and canopy-dwelling bird species, which limits our ability to determine...

Shipping pallets often are designed with the assumption that the payload carried is flexible and uniformly distributed on the pallet surface. However, packages on the pallet can act as a series of discrete loads, and the physical interactions among the packages can add stiffness to the pallet/load combination. The term ‘load bridging’ has been used to describe this phenomenon. The study reported in this paper investigated the relationships of package size, corrugated flute type and pallet stiffness to load bridging and the resulting unit-load deflection. The experimental results indicated...

The spirodienone structure in lignin is a relatively recent discovery, and it has been found to occur in lignin of various plant species at concentrations of ∼3%, which is sufficiently high to be important for better understanding of its properties and reactivity. The cyclic structure, with a β-1 bond, has been proposed to be a precursor for acyclic β-1 linkages in lignin. Previous analytical work has revealed the presence, but not the absolute configuration, of two stereoisomeric forms of spirodienone. The objective of the current work was to determine if there are thermodynamic difference...