The basis of what I am trying to do is determine what percent of forest cover is within a set of 1x1 km grid cells in arcmap. I originally attempted to do this using fishnet, tabulate area tool, and a vector layer for forest cover, but I got the error message "maximum record length has been exceeded" (if anyone knows a way to get around this without converting the vector layer to a raster, please feel free to also let me know). So, I decided to convert the vector forest cover layer to a raster and try to use the zonal statistics tool. Here, I run into problems where it seems that the numbers do not add up correctly.
I originally converted a vector forest cover layer to a raster layer. I have questions about the input for the zonal statistics table. For "input raster or feature zone data" I use my fishnet of 1x1 km2 cells, to identify the boundaries within which I want to determine the percent forest cover from the raster layer. Next, I put FID into the zone field, and I put the forest cover raster layer into the "input value raster" field. I choose mean to get the total number of pixel cells/area of forest in each grid cell. To then determine the percent forest in each grid cell, I know I could do this by just taking the number of cells of forest cover, dividing by 1000000 (in full grid cells, the total number of pixels in a 1x1 km2 grid cell) and multiplying by 100. But when I do this, the numbers for each grid cell do not appear correct, so I think something is going wrong along the way. I need help determining why the pixels are not adding up correctly.