Ben, are you asking if logs can be used as water harvesting berms? That's how I use them. Even though I have a lot of rocks, there are some places where it's easier to use logs or piles of brush, so I do. Eventually they will rot away, but before then they will have helped stabilize slopes so plants can grow.
Idle dreamer
Slideshow boring ... losing consciousness ... just gonna take a quick nap on this tiny ad ...
It's a bit like "run away to the circus" but for gardeners