Estimation of aboveground grassland phytomass with a growth model using Landsat TM and climate data

Estimation of aboveground phytomass in meadow grasslands was carried out us ing multitemporal satellite data of fine resolution but of low frequency fr om Landsat TM observations in 1984-1990. We developed two growth models for the estimation of the first-cut yield, based on an exponential plant growt h of which initial phytomass was determined using NDVI or TM2/TM3 on the La ndsat observation date together with the effective cumulative temperature d uring the growth period after the observation date. Validations of these mo dels with different data sets of Landsat TM in 1990-1994 indicated that the measured and estimated yields agreed well, suggesting the great potential of applying fine resolution satellite data coupled with a growth model to p hytomass study, in spite of the low frequency of observation.