Integrating forest inventory and analysis data into a LIDAR-based carbon monitoring system.
BACKGROUND
Forest Inventory and Analysis (FIA) data may be a valuable component of a LIDAR-based carbon monitoring system, but integration of the two observation systems is not without challenges. To explore integration methods, two wall-to-wall LIDAR-derived biomass maps were compared to FIA data at both the plot and county levels in Anne Arundel and Howard Counties in Maryland. Allometric model-related errors were also considered.


RESULTS
In areas of medium to dense biomass, the FIA data were valuable for evaluating map accuracy by comparing plot biomass to pixel values. However, at plots that were defined as "nonforest", FIA plots had limited value because tree data was not collected even though trees may be present. When the FIA data were combined with a previous inventory that included sampling of nonforest plots, 21 to 27% of the total biomass of all trees was accounted for in nonforest conditions, resulting in a more accurate benchmark for comparing to total biomass derived from the LIDAR maps. Allometric model error was relatively small, but there was as much as 31% difference in mean biomass based on local diameter-based equations compared to regional volume-based equations, suggesting that the choice of allometric model is important.


CONCLUSIONS
To be successfully integrated with LIDAR, FIA sampling would need to be enhanced to include measurements of all trees in a landscape, not just those on land defined as "forest". Improved GPS accuracy of plot locations, intensifying data collection in small areas with few FIA plots, and other enhancements are also recommended.
USDA Forest Service, Northern Research Station, Newtown Square, Pennsylvania, USA.
Kristofer D
KD
Johnson
USDA Forest Service, Northern Research Station, Newtown Square, Pennsylvania, USA.
Richard
R
Birdsey
Departments of Forestry and Geography, Michigan State University, East Lansing, Michigan, USA.
Andrew O
AO
Finley
Department of Geographical Sciences, University of Maryland, College Park, Maryland, USA.
Anu
A
Swantaran
Department of Geographical Sciences, University of Maryland, College Park, Maryland, USA.
Ralph
R
Dubayah
USDA Forest Service, Northern Research Station, Newtown Square, Pennsylvania, USA.
Craig
C
Wayson
USDA Forest Service, Northern Research Station, Troy, New York, USA.
Rachel
R
Riemann
Aboveground biomass; Carbon; Forest inventory and analysis; Inter-comparison; LIDAR