Potential and limits of NOAA-AVHRR temporal composite data for phenology and water stress monitoring of temperate forest ecosystems

We focussed on the potential and limits of NOAA-AVHRR 5-day composite data for monitoring the phenology and the fluxes of temperate forests at regiona l scale. The spatio-temporal variability of km(2) Normalised Difference Veg etation Index (NDVI) was large, and primary varied with the deciduous/ coni ferous mixture. It could provide the phenological cycle of deciduous ecosys tems. For the large coniferous Landes forest, it characterised the differen t ecotypes, and was sensitive to land use (age of the pine stands) and unde rstorey vegetation. Relationships between NDVI, T-S and rainfall confirmed the ability of km(2) thermal infrared data to infer the water status of thi s forest.