Macro script based on the macro template to process multiple images in a folder using FIJI (ImageJ) software to calculate the percentage of vegetation cover in zenithal pictures; the images are the (nearly) zenithal pictures of the plots used in the experiment at 20 different dates along the spring, summer, and autumn (not all plots present in all dates). Batch processing of the whole directory of the pictures would provide a set of csv files containing percentage (green) area on the central area of the pictures, representing plant cover for each plot at each date. These can be easily compiled using R, as all produced files share exactly the same structure (Slice -which identifies picture and thus date-, Count, Total Area, Average Size, %Area -this is the only relevant measure used afterwards in the analyses).