Validation of MODIS global LAI products in forested terrain

The leaf area index is one of key parameters for ecosystem monitoring, global carbon circulation and climate change. At present leaf area index is routinely available from Earth Observation (EO) instruments such as MODIS. However MODIS-derived estimates of LAI require validation before they are utilised by the ecosystem modelling community. The paper presents a validation of the MODIS LAI collection 5 product over forested terrain in Xishuangbanna, southwest China, based on field measurements which are upscaled using high resolution HJ image. Results suggest that the MODIS LAI product has an accuracy with R² of 0.35 and RMSE of 0.61 m²/m², and overestimates values in the high LAI broadleaf forest (where LAI>3.5 m²/m²). Further validation efforts must be carried out over the study area for an assessment of the MODIS LAI in order to improve its accuracy.