• current data on land tenure patterns within hardwood rangeland;
  
• a model of the California livestock industry which predicts the incidence and intensity of grazing;
  
• a project on land use change which will lead to a spatial simulation model of development in hardwood rangelands;
  
• CALPLAN to simulate the effects on vegetation and resource outputs of changes in management;
  
• WHR database to predict the response of wildlife to changes in hardwood vegetation;
  
• a database that assembles management response information on hardwood rangelands and adjacent annual grasslands and chaparral.
  

While FRRAP’s “toolbox” is not yet complete, FRRAP is improving the ability of IHRMP to state “what’s there now” and to predict what it will look like in the future under different policy scenarios.


Short-Term Monitoring Projects
CDF’s short-term monitoring program monitors harvest activity on hardwood range on an annual basis in order to: 1) keep informed of harvesting activity, especially areas of intensive cutting; 2) identify regional or localized harvest trends; 3) detect potentially significant short-term influences on cutting behavior; and 4) help provide direction for educational programs and other types of assistance. Several short-term monitoring projects are described below.

Aerial Flight Visual Monitoring
Using fixed wing aircraft, CDF personnel flew over about 90% of the State’s hardwood range wildland areas in order to detect and record the current season’s cutting activity, and to estimate total harvested acreage and the amount of tree canopy left after harvest. With the help of local CDF foresters and by careful observation of slash condition, litter piles, tire tracks, and other features, it was fairly easy to distinguish current activity from older cuts.

Statewide results for the 1989-1990 cutting season showed some harvest activity on about 8,600 acres, or less than one-tenth of one percent of the total 9 million hardwood range acres flown. On these sites, an average of 13% of the ground remained covered by tree canopy after the sites were harvested. By estimating former canopies, based on adjacent sites and information from local CDF foresters, CDF estimated that an average of 78% of the canopy was removed during harvest activities.

Average harvest area sizes and residual canopies varied by region due to different land uses and economic pressures. For example, the average cut size in CDF’s Region 1 which includes central and north coast counties was only 30 acres while the remaining canopy was 5%. This reflects the effects of conversions to vineyards in some of the northern coastal counties.

Hardwood Activity Reports
In 1987 CDF began a program to provide information on harvesting activity through voluntary reporting. One-page report forms were distributed to agencies, conservation groups and landowner groups. Input has come mostly from CDF field foresters, and some information has also been provided by Department of Fish and Game, the California Native Plant Society, and other interested individuals. Data from 28 reports revealed oak cutting on over 9,000 acres in the 1987 season. Cuts at 25 sites were reported, and the average cut was 365 acres. In 1988, 34 reports revealed harvesting at 31 sites for a total of about 5,200 acres, with an average cut size of 165 acres.

Comparing the aerial flight methodology with that of the hardwood activity reports, CDF has determined that the aerial flight project may provide more complete coverage of hardwood rangelands than the activity reports, is better for detecting small cuts and cuts in remote and inaccessible areas, and allows much more accurate visual estimates of tree canopies. However, since foresters and other local experts can provide valuable information about current land uses, local on-the-ground management activities, and future land use plans, it is essential to incorporate field personnel and some field reporting into any monitoring effort.

Photosurvey of Critical Deer Winter Habitat
In response to concerns by Department of Fish and Game biologists about potential impacts of hardwood cutting on deer habitat, CDF contracted an aerial photosurvey in 1988 of 300,000 acres of hardwood rangelands identified by DFG wildlife biologists as critical winter range for migratory deer. The resulting aerial photographs were compared to 1981 photos in order to quantify the amount of harvesting that had occurred between 1981 and 1988, and to estimate the residual cover. The results showed cutting on 7,200 acres over this seven-year period, or about 2.4% of the habitat photographed (0.3% annually). The average cut size was 109 acres. Remaining cover of harvested sites was estimated by canopy classes. Eighty-six percent of the areas had less than ten percent canopy cover after harvest. This project will be followed by an effort to assess the impacts to wildlife habitat values of this level of harvest activity.

Scale Mortality on Engelmann Oak
A research study started in 1990 is examining the extent and mortality of an insect scale infestation on Engelmann oaks in San Diego. The study has determined the geographic range of infestation and has identified specific sites. The next stage will look at the dynamics of infestation and mortality on various tree ages and sizes within stands. This information will help us predict the rates and impacts of infestation. Since Engelmann oak is already limited in range and also subject to intense development pressures, we will also assess the need for additional monitoring.


Applied Research
The lack of a common classification system for hardwood vegetation has made it difficult to integrate the results of different research projects. Therefore, CDF has supported the development of a detailed hardwood vegetation classification system based on the patterns exhibited by the vegetation itself. The classification scheme divides the vegetation into series, characterized generally by the overstory, and subseries which are characterized by differences in the understory. By providing a common reference framework, this classification scheme will permit research results to be interpreted and extended over the landscape.

Accurate data on the demographics of oak stands are critical to devising appropriate management strategies and policy. CDF has funded a project that quantifies rates of mortality and recruitment of Engelmann oak at several different locations in southern California through the use of aerial photographs taken first in 1928 and again in 1980. By comparing two sets of photos taken fifty years apart, the fate of individual trees has been assessed. Mortality of mature trees varied from 5% to 22% over the fifty year period and across a range of sites. Recruitment was non-existent at higher elevation sites. On inland grassland sites recruitment exceeded mortality in sparse stands, while mortality exceeded recruitment in dense stands. This method of comparing aerial photos provides a means of measuring mortality and regeneration directly, rather than inferring their rates from current stand structure, and may provide the basis for understanding the geography of regeneration failure.


Future Monitoring Needs and Directions
Since land use conversion is considered the major threat to hardwoods, the monitoring and database functions of IHRMP will need to provide increasingly precise information to policy makers, planners and landowners. Monitoring programs must produce information such as "critical area" maps which can be used to rank the value of hardwood stands as well as the development threat to them. Since valley oak and Engelmann oak are the species most threatened by development, a more detailed inventory of the value and threats to these stands is a high priority. On lands not threatened by development, the location of regeneration failure as well as its determinants remain important research issues. Since the presence of seedlings and saplings is impossible to monitor at the State level, the program must determine the relationship between regeneration failure and other features of the landscape (e.g. cover type, canopy density, topography, land use) that are more easily measured.

With respect to short-term monitoring, CDF will continue to monitor oak cutting on hardwood range on an annual basis. Short-term pressures on the resource in the 1990-1991 season may include increased demand for firewood due to rising fuel prices. Agricultural conversions are also of increasing concern in some areas, such as counties with expanding vineyard production and may require additional monitoring measures. CDF is also examining alternatives for monitoring residential conversions on a short-term basis.

CDF has determined that oak cutting on hardwood range can be visually estimated in a cost-effective manner using airplanes in conjunction with information from local experts. CDF will continue to use this method and others to answer questions about short-term behavior and trends affecting the hardwood range.

Analysis of Firewood Cutting and Range Clearing In Tehama County Tehama County has 433,000 acres of hardwood range, or the second highest amount in the State. A trip by the Board of Forestry in the mid-1980s revealed many large clearcutting operations. In the summer of 1989, CDF’s short-term monitoring flight program showed that about 2,300 acres had been harvested over the last year with an average cut size of 387 acres. In order to provide opportunity for review and input, CDF met with a representative at the livestock community and UC Coop Extension. CDF was asked to provide data on the last five years to see it cutting behavior appeared to have changed at all since the program’s inception. Working with field foresters and using data from the aerial flight, CDF estimated annual cut acreage and residual canopies for 5 years from 1985 through 1989. Estimated harvested acres ranged from 2325 to 3780. Visual observations showed that slightly more canopy was being retained now than in older cuts, and that clearcutting was no longer occurring. Opportunities for follow-up studies and outreach were discussed, such as natural regeneration field studies, development of outreach programs and workshops for firewood cutters, evaluation of the effects of IHRMP on changes in harvest methods, and interviews on post-harvest management treatments. This type of interaction and communication may provide important feedback on research and educational opportunities in other areas of the State as well, and can promote more effective cooperation to address program concerns.