Estimation of Plant Biomass by Spectral Reflectance in an East African Grassland

Abstract

Canopy spectral reflectance measurements at 0.800 and 0.675 .mu.m were made in a grassland in Masai Mara Game Reserve, Kenya. The reflectance ratio (0.800/0.675 .mu.m) was a reliable predictor of green biomass, accounting for 70% of the variance in green biomass values. Significant error in the biomass estimates was shown to be due to plots which contained < 30% of the total vegetation in the live condition. Estimation error tended to increase when time of sampling departed from the interval of 1000-1400 h, although this trend was not statistically significant. The spectral reflectance technique can provide reliable estimates of plant biomass in grassland ecosystems where the proportion of live:total vegetation exceeds 30%.