Thank for all who like this layout and appreciate to all of you.
unirdna, I agree with you, the nature aquarium dominate the current trend of aquascape contest, but there is still a lot of plant lover they like to keep aquatic plant and Dutch layout style. Here in Hong Kong, most of the hobbyist are also plant keeper, only some like us enjoy the nature aquarium.
The difficulty of this layout is not the layout idea, because I just replicate the tree grow at a slope, there is a lot of slope next to my home, so would have chance to take a closer look. The real difficulty is what you have mention "the slope". It is too hard for me to set up, because I have to clean up all Seachem substrate from the tank and move it back again, I only take the photo after it finish.
How to concrete it and don't let it slip down? Actually, it is too difficulty to explain in a short paragraph, simply said that it is a under substrate filter system at the bottom. Since I haven't take the picture, so give me some time to draw and write an article about how to setup the slope, I will post the set up later.
SearunSimpson, I am sorry that I haven't take the setup step by step photo, I just layout it as according to my idea to plant the moss with some photo reference, but one thing very important is how to position your plant. The rule of thumb is to align with the prespective grid. For a nature aquarium, all the position of hardscape and plant should simulate as a real sense, the prespective rule is the basic, like bigger at front smaller at the back.