Hemispherical photographs for estimation of leaf area index of Caatinga vegetation in Brazil, 2017-2019

The dataset contains raw hemispherical photographs of canopy structure representative for 0.5 ha permanent plots (26) across Caatinga area in Brazil. The photographs were taken between March 2017 and August 2019, using a digital camera (NIKON D100) with a Sigma 4.5 mm F2.8 fisheye lens. When processed the photos provide a representative value of LAI (Leaf area index) for the plot.,The photos were taken using a digital camera (NIKON D100) with a Sigma 4.5 mm F2.8 fisheye lens. Under overcast sky conditions one picture was taken on each intersection of four subplots resulting in a total of 36 photos in each plot for 12 plots. For other sites, one photo was taken at the centre of the subplot. Pictures were taken with the top of the camera facing North at a height of approximately 1 m. The quantity of photos for each plot may vary because in some occasions there was a problem with the trigger bottom of the camera, or rapid changes in sky conditions precluded taking a picture at that location or necessitated rejection of the image afterwards. When processed the photos provide a representative value of LAI for the whole plot, not for individual subplots as the image, depending on vegetation height, may include tree canopies up to 20 m distance from the camera.