These leaf area index (LAI) maps are created every 10 days during the growing season (1 April to 30 November) using cloud-free 10-day composites of AVHRR. The data pre-processing for compositing, cloud-screening, atmospheric correction, BRDF correction, etc. were done at the Canada Centre for Remote Sensing. LAI is defined as one half the total leaf area per unit ground surface area. For sloping surfaces, the ground area is projected to the nadir view direction.