Document: DOW-3-65-19

Estimating foliar biomass in a forested watershed based on remote sensing data.

KIM, S.*, S.KANG and D.LEE

Seoul National University, Sillim-Dong, Seoul 151-742 South Korea ¹

Abstract:
The objective of this study was to describe spatial distribution of foliar biomass in a forested landscape of Korea, based on remotely sensed data from satellites. The area was classified into hardwood and coniferous patches by examining difference of two images of thematic mapper (TM) taken in early spring and mid-summer, and extracting reference points from the vegetation map. Leaf area index (LAI) was determined with LI-COR 2000 at the 40 points around the site in 1998 and 1999. The cell-based LAI of each forest patch was estimated by comparing the ground truths with normalized difference vegetation index (NDVI) or simple ratio (SR) calculated from the satellite imagery of TM. The Spatial distribution of LAI was determined at a watershed scale by statistical regression between the ground truths and NDVI or SR. The correlation coefficient of estimated and measured LAI was 0.6 for the hardwood patch. To estimate specific leaf area (SLA), leaves were collected and attached to a white paper. The material was scanned or taken a picture of with a digital camera. The area of leaf image was determined with a GIS-based procedure. After the leaves were oven-dried and weighed, specific leaf area (SLA) was calculated. Finally, foliar biomass was calculated by dividing LAI by SLA. Our methods indicate that the spatial distribution of foliar biomass at a specific time can be obtained economically. By calculating spatial autocorrelation index such as Moran's index and foliar biomass at the same altitude from the resultant grid, the spatial distribution of foliar biomass was prepared and interpreted easily.

Keywords: LAI, SLA, Remote sensing, GIS

This abstract is being presented at: 10:30 AM in session:
REMOTE SENSING