A cost-effective field measurement protocol to support lidar-assisted carbon monitoring programs—implementing a prototype design at six different sites in the United States

Legner, Kate; Andersen, Hans-Erik; Cooke, Andrew; Cohen, Warren. 2020. A cost-effective field measurement protocol to support lidar-assisted carbon monitoring programs—implementing a prototype design at six different sites in the United States. Gen. Tech. Rep. PNW-GTR-984. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 66 p. Given the increasing interest in the use of lidar-based remote sensing to support carbon monitoring systems, including those used for measurement, reporting, and verification requirements for REDD+ (reduced emissions from deforestation and degradation) programs in tropical nations, there is a corresponding need for the cost-effective field measurement systems to enable model development and robust assessment of uncertainty in these programs. In this report, we describe an efficient field sampling design and measurement protocol designed to provide field-based estimates of biomass/carbon stored in trees and coarse woody materials to support complex, multilevel carbon monitoring systems using Landsat time series and airborne lidar. Airborne lidar data were collected as a strip sample (single flight lines spaced 5 km apart) at six sites in the United States (Colorado, Maine, Minnesota, Oregon, Pennsylvania/New Jersey, and South Carolina) (298 total flight lines), and about 50 field plots were established within the lidar coverage at each site. Field plots were distributed across 15 (3 cover × 5 height) strata at each site, using field protocols that were consistent with those of the U.S. Department of Agriculture Forest Service Forest Inventory and Analysis program. Field measurements were collected digitally on personal tablets and uploaded daily into a database. Preliminary regression analyses indicate strong relationships between lidar metrics and tree biomass at all sites.