Bob Izlar

NAME Bob Izlar
TITLE Director
DEPARTMENT Center for Forest Business
PHONE 706-542-6819
FAX 706-542-5073
ADDRESS University of Georgia
Warnell School of Forestry and Natural Resources
180 East Green Street
Athens, Georgia 30602
EDUCATION BSFR, University of Georgia, Forest Management
MFR, University of Georgia, Forest Management
MBA, Georgia Southern University, Finance
RESEARCH INTERESTS Harvesting, transportation, and use of woody biomass as feed stock

Bob Izlar



Researchers: Bob Izlar, Director and Professor
Dale Greene, Professor
Michael Westbrook, Graduate Student

Center for Forest Business
Warnell School of Forestry and Natural Resources

A recent study by the Center for Forest Business and Langdale Company of Valdosta evaluated how to modify a conventional tree-length pine harvesting operation to capture forest biomass. We added a small 260-hp chipper (Conehead 565) to a mechanized, tree-length system to also harvest tops, limbs, and understory (dbh 1-4 inch) biomass. Three replicates of three treatments (A-tree-length only, B-tree-length with limbs & tops chipped, C-tree-length with limbs, tops, and understory chipped) were evaluated in a 33-year-old slash pine plantation on a flatwoods site in the lower coastal plain of Echols County, GA. The site contained an estimated 7.7 tons per acre of understory biomass with an average dbh of 2 inches. Water oak, swamp bay, and red maple accounted for 73% of the stems. Roundwood production averaged 65.8 tons per acre and did not differ significantly across the three treatments. A load of chips was produced for every 18 and 5 loads of roundwood in Treatments B and C, respectively.

There were significant differences in the chips produced between treatment B (3.8 tons per acre) and treatment C (10.8 tons per acre) at the 10% level but not at the 5% level. Total hourly production averaged 28.6 tons per scheduled machine hour and did not differ significantly across the three treatments. Chips averaged 50% moisture content (wet basis) when produced and lab results showed heat content values of 19.1 MJ/kg, comparable to other woody biomass. Nutrient removals from the site were relatively low with losses associated with Treatment B comparable to annual atmospheric deposition. Raking costs associated with site preparation were significantly reduced ($23 per acre) on Treatment C where understory was also chipped. Both treatment B and C resulted in significantly less acreage lost to debris piles after site preparation with approximately 1.0 percent of the area in piles compared to 1.7 percent for tree-length harvesting without chipping residuals.


Izlar, B. 2006. The Centennial History of Forestry in Georgia: A pictorial journey. Donning Co., 180 p.

Yin, R. and Izlar, B. 2001. Supply constraints and portfolio insurance: Applications of financial engineering to institutional investors. Journal of Forestry. 99(5) 39-44.

Yin, R., Harris, T. G. and Izlar, B. 2000. Why Forest Products Companies May Need to Hold Timberland. Forest Products Journal. 50(9)39.44.