Wood Volume Estimation of SOD Infected Coast live oak in Marin County
John Shelly1, Katalin Jackovics2, Ramnik Singh3, and Tad Mason4
Sudden oak death has dramatically increased the number of dead and dying trees in areas with a high incidence of infection. These infected trees contribute greatly to the potential hazard for wildfire, physical damage, injury, and disease spread. This situation has led to an interest in developing management strategies to deal with the removal, disposal, and possible utilization of infected trees. One of the most important pieces of information needed to plan for future disposal and utilization needs is a reliable estimate of the volume of material that must be dealt with in both the short term and the long term. Ariel surveys and satellite imagery are known to be helpful in identifying areas of infected trees and even individual trees. However, the lack of information on tree volumes for many of the host species makes it difficult to use this remote sensing data to estimate the volume of infected wood that may be available for disposal or utilization. A relationship between crown spread and wood volume could be used to predict wood volume from remote data.
The purpose of this study is to estimate the amount of SOD infected biomass available for utilization and/or disposal in Marin County. The goal is to develop a volume model based on aerial surveys that can expedite the inventory process throughout all infected counties. Timber cruise data, including the area of the canopy cover, has been collected on 87 Quercus agrifolia (coast live oak) trees from a one acre plot in China Camp State Park, San Rafael, CA. Data measured includes canopy size, DBH, total tree height, merchantable height for lumber (up to 8-inch top), and main stem height to a 4-inch top. This data was used to calculate average merchantable wood volume and total biomass volume of the main stem. Canopy size of each tree was estimated by measuring the distance in the four cardinal directions from the center of the tree to the edge of the canopy. The data was analyzed by regression techniques to develop a correlation between canopy size and both merchantable volume and biomass volume. Although preliminary crown spread data resulted in less than ideal correlation coefficients, the method shows promise. Recent refinements in measuring technique and model description are expected to improve the correlation. If successful, the technique will be applied to other host species. These relationships will then be used to estimate total volumes of infected wood from the crown spread areas measured in aerial and satellite surveys.
This project is funded in part by USDA Forest Service - State and Private Forestry, Pacific Southwest Region (Agreement 01-DG-11052021-211) and the County of Marin.
1Cooperative Extension Advisor, UC Forest Products Laboratory, 1301 South 46th Street, Richmond, CA 94804; (510) 215-4210; john.shelly@ucop.edu
2Staff Research Associate, UC Forest Products Laboratory, 1301 South 46th Street, Richmond, CA 94804
3Post Graduate Research Scientist, UC Forest Products Laboratory, 1301 South 46th Street, Richmond, CA 94804
4TSS Consultants, Rancho Cordova, CA
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