Interesting, Victor. I'm glad you are posting this, because bark chips are popular, but until they break down plants have to have access to soil, manure and compost. And what kind of bark chips makes a big difference. Some
trees will really inhibit growth.
Bark beetles will be happy, but until that wood breaks down, and even then, it can only contribute a limited amount of nutrition for plants and for us. And when you think about it, bark chips got popular as an attractive cover around landscape that suppressed weeds. But that means suppression for everything. We are trying to create an environment where varieties of soil bacteria and soil fungi can thrive.
Even a
Hugelkultur bed takes time for wood to break down, but that wood is surrounded by soil, the wood is soaked, maybe even manure around it too, so the plants have a variety of things to take from.
I wouldn't use more than an inch of bark chips at a time. If you thin out and bury those bark chips it will help a lot. Soak them in natural nitrogen first
My favorite kind of raised bed is layering as many different kinds of organic matter as you can get, wheat and oat
straw, leaves, weeds, manure, rock powders, compost in thin, mixed layers, especially over clay soil.
An important distinction: Permaculture is not the same kind of gardening as organic gardening.
Mediterranean climate hugel trenches, fabuluous clay soil high in nutrients, self-watering containers with hugel layers, keyhole composting with low hugel raised beds, thick Back to Eden Wood chips mulch (distinguished from Bark chips), using as many native plants as possible....all drought tolerant.