A Dynamic Model of California's Hardwood Rangelands

Low profitability of hardwood rangeland manage­ ment, and oak tree harvesting for firewood markets and forage enhancement has led to concern about the long-term sustainability of the oak resource on rangelands. New markets for recreational hunting may give value to oaks for the habitat they provide for game species, and broaden the economic base for managers. A ranch level optimal control model has been developed to assess optimal oak tree canopy and livestock stocking under different biological and economic conditions. The impact of recreational hunting on management was also assessed. In general, hunting improved the economic return on hardwood rangelands, and resulted in lower oak harvest levels and lower livestock stock­ ing. The policy implication is that public concern over oak tree harvesting may be partially alleviated by new markets for recreational hunting on hardwood rangelands. California's oak-covered rangelands occupy 7.4 million acres (California Department of Forestry and Fire Protection 1988). Over eighty percent of the area is privately-owned, providing one-third of the forage for the state's livestock indus­ try. The public goods supplied by hardwood rangelands, including wildlife habitat, watershed protection and aesthetics, have led to strong public interest in the management of these private lands. One of the important ecological characteristics of this area is the interconnectedness of large expanses of woodland. Conversion of hardwood rangelands to urban or intensive agricultural use is one of the leading sources of habitat loss and fragmentation, amounting to around seven percent of the oak woodland acreage between 1950 and 1980 (Bolsinger 1988). Oak clearing for forage enhancement was at one time a major source of habitat loss, however this practice peaked in the 1950's and 60's (George 1987). Rapid increases in firewood prices in the 1970's (Doak and Stewart 1986) suddenly gave value to the oak trees on rangelands, resulting in increased firewood harvest. Poor oak regeneration has also been documented in some areas, leading to some concern about the long-term sustainability of this resource (Muick and Bartolome 1987). These concerns about the future of this valuable resource have resulted in zoning restrictions and ordinances at the local level, and proposals for statewide regulation of tree removal. However, no empirical estimates have been made of the effect of current and future economic conditions on landowner manPresented at the Symposium on Oak Woodlands and Hardwood Rangeland Management, October 31 November 2, 1990, Davis, California. Forest Management Specialist, Dept. of Forestry and Resource Management, University of California, Berkeley; Professor, Dept. of Agricultural Eco­ nomics, University of California, Davis. agement decisions for these large expanses of private land. Private hardwood rangeland profitability directly affects the rate of fragmentation due to subdivision. The forces impacting oak tree harvest, such as income from firewood and increased forage for livestock, affect the structure of the tree canopy and its value for different wildlife species. New markets for fee hunting on private rangelands have recently developed in the state. Since many of the game species demanded by hunters are enhanced by oak cover, this new market may serve to provide a market-based oak conservation incentive for landowners.