Thank you for answer. It was very helpful and could make a further step.
In the zonal statistics i can calculate different values.
I got the following results out of plots:
But now i don`t realy know how to understand this data.
What is the going to be counted? Are these the pixels or the pixel values.
I want to know the number of green pixels per plot ...
The ArcGIS Combine tool is for rasters and not vector data. So, to use that you would have to first rasterize your data. However, that is what I would recomend for change detection anyway. The following assumes you rasterize your data:
In QGIS, you have a number of options:
From the Processing Toolbox use Orfeo's MultivariateAlterationDetector (just ...