In a permaculture system, any one element serves as many intended functions as possible, and as I touched on earlier, introduced elements often end up serving all sorts of unintended functions. For example, a fruit tree can offer shade and wind protection for plants around it. The fallen leaves shelter the soil as mulch, and eventually break down into humus. Worms are encouraged in the surrounding soil, and worms become occasional food for wild birds, who also use the tree. However, the original intention in planting the tree may have only been to grow fruit.
An element may be added to a permaculture landscape with only one function in mind, but it’s important to observe how the element is integrated or can be further integrated into the system.
For example, I moved my worm trough into the backyard as an isolated unit for breeding composting worms. The only way I involved the worm trough was to grow a screen of bana grass along the north side to shade the unit in Summer. However, I’ve since noticed that the trough provides a sheltered spot where I could grow some medicinal plants. Also, wild birds use the worm trough as a landing perch. I now have an idea to leave bird seed there for them, and perhaps a bowl of water. Maybe I could collect and compost the bird poop.
As another example, my biogas digester was an isolated project. I wanted to cook on the gas it produced. I had a vague idea that I would throw the effluent around the soil, but now it plays more of a part in the backyard. I’ve taken to distributing the effluent around seedlings and potted plants to give them a boost. Every now and then I use it to water the bana grass and to water the beans growing on the rebar fence trellis. I’ve even used it to inoculate compost materials with good bacteria. I now see it as a valuable part of the backyard, and not at all isolated.
Of course, no one can properly predict all the functions an element may serve, and striving for so many could do your head in. Consider as many possibilities as you can, then introduce elements in as much accordance as possible with all that you’ve explored. Then sit back and watch as nature makes full use of it!