Observations on the sensitivity of ERS-1 SAR image intensity to changes in aboveground biomass in young loblolly pine forests

Abstract

A study was conducted to evaluate the sensitivity of the microwave return recorded by the ERS-1 C-band synthetic aperture radar ( SAR) to changes in above-ground woody biomass in young loblolly pine forests ( dry weight biomass ⩾ 6kgm^{− 1} Radar backscattering coefficients were derived from ERS-1 SAR imagery collected over 15 test stands near Durham, North Carolina, United States. Ground reference data were collected in order to characterize the aboveground biomass of the pine trees in the test stands. Significant linear correlations atp = 000l or better) were found between the radar backscattering and the various components of biomass ( both wet and dry weight) of the pine canopy ( e.g., bole biomass, stem biomass, needle biomass, canopy biomass and total biomass). The linear correlation coefficients ranged between 087 and 0-93. These results demonstrate the potential for using the C-band ERS-1 SAR to monitor biomass changes during the early successional stages in temperate coniferous forests, as well as throughout later successional stages in coniferous forests with lower overall growth rates, such as those found in boreal regions.