FIA Volume and Biomass Variables : A Look at Current Status and Needs Raymond M. Sheffield Southern Research Station Larry DeBlander Rocky Mountain Research Station Photo Credit: Mary Ann Fajvan, West Virginia University,

Objectives Review current volume/biomass variables Review inconsistencies/limitations Changes needed to correct problems/voids List possible new variables to address current needs Next steps

Background Volume/Biomass Variables Definition Team Multiple Band Membership (AB, IM, DAB) Goals: –Which of the present FIADB volume/biomass variables are needed? –Which are national or regional in nature? –How to define, document, field collect, calculate, and populate the needed variables? Brief Summary of Work to Date

Current Volume/Biomass Tree Variables VOLCFNET –For trees with d.b.h. >= 5.0 inches, net cubic-foot volume in central stem from 1-ft stump to a 4-inch top d.o.b. –Gross merchantable volume minus cull deductions VOLCFGRS –As above but without cull deductions Merchantable portion 1-foot stump 4-inch top d.o.b

Current Volume/Biomass Tree Variables VOLCSNET –Net cubic-foot volume in the saw-log portion of sawtimber size, growing stock trees VOLCSGRS –As above but without cull deductions Saw-log portion 4.0 inch top d.o.b. Saw-log top

Current Volume/Biomass Tree Variables VOLBFNET –Net board-foot volume in the saw-log portion of sawtimber size, growing stock trees VOLBFGRS –As above but without cull deductions Saw-log portion 4.0 inch top d.o.b. Saw-log top

Current Volume/Biomass Tree Variables DRYBIOM –For trees with d.b.h. >= 5.0 inches, merchantable stem biomass in oven-dry weight. –Gross biomass including bark in central stem from 1-ft stump to a 4-inch top d.o.b. Merchantable portion 1-foot stump 4-inch top d.o.b

Current Volume/Biomass Tree Variables DRYBIOT –The total aboveground gross biomass of a sample tree 1.0 inch diameter or larger, including all tops and limbs (Oven-dry weight) –Excludes foliage –Only volume/biomass variable populated for trees < 5.0 inches

Problems with Current Variables Inconsistently defined and populated Provide incomplete information on forest volume and biomass

Inconsistent Definition/Calculation Western woodland species not accommodated in definitions Cull (defect) deductions vary widely Lack of national core Tree Class variable affects all Growing Stock variables, especially Sawtimber Salvable Dead class of timber not nationally defined Biomass variables

Western Woodland Species: Where’s the Merchantable Portion? Merchantable portion

More inclusive definition… Volcfnet: The net cubic-foot volume of the of a live tree 5.0 inches diameter or larger. Volcfnet: The net cubic-foot volume of the merchantable portion of a live tree 5.0 inches diameter or larger. merchantable portion Merchantable portionMerchantable portion: Merchantable portion –That portion of the central stem of a timber species tree from a 1-foot stump to a minimum 4-inch top diameter, or to where the central stem forks, where all are less than 4.0 inches diameter, OR –That portion of a woodland species tree from the DRC measurements to the 1.5-inch ends of all the qualifying stems.

Inconsistent Definition/Calculation Western woodland species not accommodated in definitions Cull (defect) deductions vary widely (dead trees esp. problematic) Lack of national core Tree Class variable affects all Growing Stock variables, especially Sawtimber Salvable Dead class of timber not nationally defined Biomass variables

Cull (defect) deductions vary widely Volcfnet: a cubic foot value populated by deducting both sound and rotten/missing cull for some FIA units; others only deduct rotten/missing Broken stems cause major inconsistencies

Merchantable portion Sound cull 4.0 inches d.o.b.

Proposed definition of “net” cubic volume Net cubic-foot volume - Gross cubic-foot volume minus deductions for rotten/missing cull

Other Problems with Cull Deductions Merchantable portion 4.0 inches d.o.b. Rotten or missing Missing top

Rotten/Missing Wood Not Collected For Dead Trees in Some Regions (Core Optional) Photo: Chris Schnepf, University of Idaho,

Inconsistent Definition/Calculation Western woodland species not accommodated in definitions Cull (defect) deductions vary widely (dead trees esp. problematic) Lack of national core Tree Class variable affects all Growing Stock variables, especially Sawtimber Salvable Dead class of timber not nationally defined Biomass variables

What are we missing? “Net” biomass estimates –Do we need to distinguish “missing” wood from “decayed” wood? Standing dead trees < 5.0 inches d.b.h. Estimates of green biomass Total tree stem volume and biomass

4.0 inches d.o.b. Merchantable portion Saw-log portion Total Stem Volume/Biomass Let’s Move Beyond Outdated Merchantability Standards

New Variables Coming Your Way? VOLCFSTEMNET: Net cubic-foot volume of the main stem of a tree 1.0 inch diameter or larger. VOLCFSTEMGRS: Gross-cubic foot volume of the main stem of a tree 1.0 inch diameter or larger. DRYBIOSTEMNET: Net above ground biomass of the main stem of a tree 1.0 inch diameter or larger (oven dry weight). DRYBIOSTEMGRS: Gross above ground biomass of the main stem of a tree 1.0 inch diameter or larger (oven dry weight). DRYBIOSTEMGRS: Gross above ground biomass of the main stem of a tree 1.0 inch diameter or larger (oven dry weight).

New Variables: “Net” Biomass DRYBIOTNET: Net above ground biomass of a tree 1.0 inch diameter or larger (oven dry weight). DRYBIOMNET: Net above ground biomass of the merchantable portion of a tree 5.0 inches in diameter or larger (oven dry weight).

National Volume Equations Encourage development and testing of national equations for volume and biomass VOLCFNETNAT: National FIA variable to house results of national equations to facilitate testing/validation.

Other Recommendations Make Tree Class (and Growing Stock) National Core Conduct more “all live” and total biomass analysis now so we aren’t limited to growing stock trends in the future

What’s Next? Change Proposals !!!!!!!!! Revise Change Component Variables