AN IMPROVED VOLUME, BIOMASS, AND CARBON DATABASE FOR U.S. TREE SPECIES James A. Westfall U.S. Forest Service Forest Inventory and Analysis

JUSTIFICATION  Published papers, as well as our own experiences, have shown that substantial differences exist among tree biomass model predictions.  To help ensure FIA estimates provide an accurate representation of forest biomass resources and trends, comprehensive data on tree biomass are needed. These data would provide  a means of assessing current FIA methods, and  a basis for nationally-consistent estimation of volume/ biomass/carbon

FIA BIOMASS STUDY  Initial focus is on top 10 species in the West and top 20 species in the East – these species account for approximately 65% of tree volume in the East and 80% of tree volume in the West.  Cooperators/Technical assistance  Univ. Maine, Virginia Tech, Oregon State, Michigan State, Univ. Montana, Univ., Georgia  NCASI, Rayonier  Forest Management Service Center

FIA BIOMASS STUDY  Year 1 – take intensive tree measurements to better understand within- and among-tree variability such that efficient and effective protocols can be implemented in future years.  Approximately 230 felled trees were measured for biomass and sample disks taken back to lab for analysis. Currently evaluating these data to refine field protocols and examine total sample size requirements.

FIA BIOMASS STUDY  Costs – Per tree costs largely depend on tree size; across the entire study, roughly $1000 per tree is estimated. Note this was for intensive measurements which should be reduced in subsequent work.

FIA BIOMASS STUDY  Costs – The per tree costs also included lab processing of disks – which should be substantially reduced as we begin using the SRS lab in Athens and hopefully switch to ½” cores for processing.  Total cost estimates – derive from per tree cost and total number of trees. Currently working to evaluate: 1) expect per tree cost to decrease, but actual amount uncertain; 2) total sample size – have some cursory analyses, but further investigation is needed.

FIA BIOMASS STUDY  Geographic Sampling Strategy – need to ensure sufficient spatial dispersion of sample trees to cover range of species occurrence and stand conditions (e.g., density, climate).  Currently evaluating best approach to this issue using concepts similar to those employed in the NRS taper study. A certain amount of adaptability will be needed for felled tree work, as the locations where trees can be felled and weighed are limited.

FIA BIOMASS STUDY  Ancillary data – leverage other possible data sources to better capture spatial gradients in allometry and wood density.  Utilization studies  Other biomass work (NFS, Exp. Forests, etc.)  FIA plots? (taper, density)  Need to determine which measurements may be useful and the feasibility, e.g., a lot of utilization work is done under existing agreements.

FIA BIOMASS STUDY  Legacy data – leverage existing FS, industrial, and university data to better capture spatial gradients in allometry and wood density.  Taper data  Biomass studies  Density measures  Need to determine how to incorporate these data into our framework in a balanced manner. What are the appropriate statistical techniques to employ?

FIA BIOMASS STUDY  Issues and Challenges  Collecting biomass data is difficult and time consuming (= high cost).  Large portion of forest area not accessible for felled-tree work.  High variability in environmental and tree characteristics requires substantial sampling effort.  Large trees are costly to measure but also represent information gap in many studies; have high economic value; relatively rare.

FIA BIOMASS STUDY  Journal paper  Peer-reviewed manuscript draft nearly complete that focuses on limitations of existing biomass models and presents various recommendations for future improvements.  Presentations  FIA Symposium – dedicated session with 6 papers  Southern Mensurationists  Northeastern Mensurationists Organization

QUESTIONS ??