Richard B. Standiford

Solving Empirical Bioeconomic Models: A Rangeland Management Application

An empirical bioeconomic model was developed for private ranches conducting firewood, cattle, and hunting enterprises on Californias hardwood rangelands. Hunting, forage, cattle, and oak firewood production functions were derived. Nonlinear optimal control was used to solve for two state and four control variables to give optimal time pathways for oak density and cattle stocking. Risk was considered through use of chance constraints, rainfall variability, and price expectations. Commercial hunting is shown to be the dominant economic value on these rangelands. Inclusion of stochastics shifts production away from cattle to less risky firewood and hunting enterprises.

Multiple use management of California's hardwood rangelands.

The importance of evaluating multiple resource values on rangelands is demonstrated in this study of Californias 3.0 million hectares of oak-covered (Quercus spp.) hardwood rangelands. Production functions are derived for oak tree growth on rangelands for stands with at least 50% of the total tree cover in blue oak (Quercus douglasii Hook. & Arn.) based on oak volume per acre and site index. Forage production is estimated based on oak cover, weather variables, growing period, and site factors from data reported in the literature. Hunting revenue and cost functions are derived from a survey of commercial hunting clubs, and are based on oak cover, hunter success variables, hunter demographics, advertising, livestock density, and club size. The interrelationship of these resource values is shown in output from an optimal control model that incorporates these production functions. Oak trees are gradually cleared for situations where cattle are the only economic product, whereas a residual tree canopy is maintained for cases where firewood and hunting enterprises are considered. In addition, cattle stocking is higher and net profitability is lower for the cattle only management scenario when compared with a multiple use management scenario. The development of these multiple use production functions allows the full range of resource management options to be considered.

Attraction of ambrosia and bark beetles to coast live oaks infected by Phytophthora ramorum

1 Sudden oak death is caused by the apparently introduced oomycete, Phytophthora ramorum. We investigated the role of bark and ambrosia beetles in disease progression in coast live oaks Quercus agrifolia.

Spatial pattern dynamics of oak mortality and associated disease symptoms in a California hardwood forest affected by sudden oak death

Sudden oak death is a disease affecting coastal forests in California and southern Oregon. The spatial pattern of disease dynamics is important for forest and landscape pathology; in this work we investigated the interaction across landscape scales of disease symptomology in coast live oaks, Quercus agrifolia, (trunk bleeding, presence of beetles, and presence of the fungus Hypoxylon thouarsianum) and tree mortality through time. We used two-dimensional spatial analysis tools with data gathered in point-centered-quarter format in 2001 and 2004 to quantify the population density of the disease through time; to examine the spatial pattern of tree mortality across scales through time; and to examine the spatial co-occurrence of disease symptoms with crown mortality through time. Early in the study period dead trees were strongly clustered at smaller scales (~300 m) and after three years this clustering was less pronounced. Bleeding on trees occurred in clusters away from dead trees, particularly in 2004, likely indicating a new cohort of infected trees. The presence of H. thouarsianum was strongly related to overstory mortality through time. Beetle-infested trees co-occurred with mortality in 2001. By 2004, they occurred throughout the forest, and were less strongly correlated with overstory tree mortality, suggesting a future peak of tree mortality.

VALUE OF OAK WOODLANDS AND OPEN SPACE ON PRIVATE PROPERTY VALUES IN SOUTHERN CALIFORNIA

This paper evaluates the extent to which dedicated open space in California’s oak woodlands in a rapidly urbanizing area in southern California, influences private land and home prices. The Santa Rosa Plateau area in southern Riverside County was the location for this pilot study. Data on home and land value for 4,800 parcels surrounding an 8,300 acre oak woodland open space owned and operated a private land conservancy were collected. This was merged with spatial data from vegetation maps using a geographic information system (GIS). Distance from each parcel to the edge of the open space land, to the nearest trailhead and to the nearest stand of native oaks was calculated. Hedonic regression showed that both land and home value decreased as the distance from the open space boundary, trailheads, and local stands of native oak habitat increased. The model results were applied to the overall home and land parcels in the study area. A decrease of 10 percent in the distance to the nearest oak stands and to the edge of the permanent open space land resulted in an increase of

Working Landscapes of the Spanish Dehesa and the California Oak Woodlands: An Introduction

4 million in the total home value, and an increase of

Proceedings of a workshop on Eucalyptus in California. June 14-16, 1983, Sacramento, California.

16 million in total land value in the community. This demonstrates the off-site benefits of open space areas and native oak woodland stands in increasing overall land and home value of an entire community. There is economic value for conservation of native habitats. This promising method of analysis will be useful in future work to characterize how different configurations of open space design influence the land and home markets.

Models of Oak Woodland Silvopastoral Management

Oak woodlands have offered a welcoming environment for human activities for tens of thousands of years, but how that history has unfolded has many variations. The long-time collaboration that led to this book ran into complications arising from the different meanings attached to many a term, including struggles over the most appropriate title, settling on common units of measurement and area, quantifying the woodland’s extent in Spain and California, and even in deciding how many oaks constitute a woodland. Defining with anything approaching international precision such terms as oak woodlands, oak woodland ranches, and wooded dehesas is nuanced, and is compounded by distinctions in culture and language. But our efforts to dovetail one inscrutable system with another may offer insight into the relationship of humans with environments long occupied and modified, as further shaped by location, history, and opportunity. In 15 chapters we offer a comparison of conservation and management on California oak woodland ranches and in the dehesas of Spain, including economic, institutional, ecological, spatial, and geographical aspects, from how to raise an Iberian pig to what we can learn about oak woodlands with remote sensing.

Modeling Multifunctional Agroforestry Systems with Environmental Values: Dehesa in Spain and Woodland Ranches in California

To provide up-to-date information on Eucalyptus in California, researchers from Califor-nia, Florida, Hawaii, Oregon, and France presented papers on species selection, products, uses, and economics, growth and yield, cultural requirements, propagation, and breeding programs. This Proceedings of the Workshop should serve as a useful reference for landowners, foresters, nurserymen, horticulturists, and others who are planning to plant Eucalyptus.

Proceedings of the Redwood Region Forest Science Symposium: What does the future hold?

Spanish dehesas and California ranchlands provide a diverse array of woodland-produced commodities, including forage, wood, acorns, habitat, game, and amenities. Several silvopastoral models exist for analyzing such production. An examination of management scenarios that include encouraging natural regeneration in dehesa is offered, and then compared with management where no extra inputs are provided and the tree overstory is gradually lost over time. A significant issue in Spain and California alike is sustaining production while making certain there is natural regeneration and recruitment of the oaks. A sensitivity analysis of public inputs, product prices, and discount factors is provided. Silvopastoral models for California woodlands illustrate the importance of incorporating actual landowner behavior in policy analysis to accurately represent the future trajectory of oak woodlands.