posted 11 years ago
Swales are agroforestry systems, trees can go right into them. The difference is that they don't have the woody core, which breaks down over time. If the decomposing wood is underneath a tree it will likely destabilize the tree and it very possible that the tree is up rooted during a strong wind.
Just to clarify the first illustration is the "correct" approach, the following image is the "incorrect" approach, as labeled in Sepp Holzer's Permaculture.
I can't see clearly enough in your screen capture to be able to tell anything. I wouldn't be surprised if this is something Sepp has tried before, but I didn't see any trees in any hugelkultur at the Krameterhof or the Holzerhof. Berry bushes absolutely, this is what the Hugelkultur at the Krameterhof are used for now. If there were fruit trees in hugelkultur at some point they are either not there anymore, or the hugelkultur is so small that you can't tell it is there. The illustration clearly has fruit trees above and below but not in the hugelkultur.