PARENT SESSION
Oral Session #60: Remote Sensing and GIS. Presiding: A. Gallant.
Thursday, August 9, 2001. 8:00 AM to 12:00 PM. Hall of Ideas E.
Relationship between vertical canopy profiles and biomass in a neotropical rainforest.
Drake, Jason 1, Dubayah, Ralph1, Knox, Robert 2, Clark, David3,4, 1 2 3 4
ABSTRACT- Accurate estimates of the total biomass in terrestrial vegetation are important for carbon dynamics studies at a variety of scales. Although biomass is difficult to quantify over large scales using traditional techniques, lidar remote sensing holds great promise for biomass estimation because it can directly recover canopy height and structure. In this study our primary goal was to explore the sensitivity of lidar to vertical canopy structure and the degree to which changes in canopy structure are related to changes in aboveground biomass in a tropical rainforest. We first examined the relationship between simple vertical canopy profiles derived from field measurements and the estimated aboveground biomass (EAGB) across a range of field plots located in primary and secondary tropical rainforest and in agroforesty areas. We found that metrics from field-derived vertical canopy profiles are highly correlated (R^2 up to 0.94) with EAGB across the entire range of conditions sampled. Next, we found that vertical canopy profiles from a large-footprint lidar instrument were closely related with coincident field profiles. As a result, metrics from lidar profiles are also highly correlated (R^2 up to 0.94) with EAGB across this tropical landscape. These results help to explain the nature of the relationship between lidar data and EAGB, and also lay the foundation to explore the generality of the relationship between vertical canopy profiles and biomass in other tropical regions.
KEY WORDS: aboveground biomass, canopy structure, tropical forests, lidar remote sensing