A food forest aims to be a natural forest formed mainly by edible species, assuming is the most natural way of producing food. If we observe, any forest is made up by a huge number of species that could be divided into seven layers: large trees or canopy, low trees, shrub, herbaceous, rhizosphere, soil surface and climbers. We can also add two more layers: aquatic and fungal layer.
In a wild forest, those layers appear in succession and each have a function on the joint: source of nutrient, mulching, shelter for animals, control pest, etc. At the beginning lower levels are predominant, which benefit the soils reducing the compaction and adding organic matter. This is how trees and shrub find better conditions to develop season by season. As they grow, they create shadow to lower layers, that cease to be predominant. After some time, other layers appear as fungal/mycelial layer or wild animals. It is in this way that we create a symbiosis, a resilient ecosystem able to retain humidity and create a micro climate that needs almost no maintenance. Permaculture try to imitate this natural succession speeding up the cycles.
What it takes a hundred years to develop, it can be established in less time. For this purpose, observe the soil is crucial. We need to know what kind of soil we have (clay, sand or loam), how depth it is, actual state of it (if suffer from agricultural or livestock activities, if phytoquemicals were used on it, how much organic matter it has, etc.) If we have a rich soil, we will be able to speed up succession and create better conditions for upper levels. In a food forest, as in a wild forest, everything is about the soil. Go to the forest and observe it.
In this case, we have a sandy/loamy soil, depth and exposed to livestock activities. In order to increase fertility we planted green manure, a mix of oats, wheat, mustard, clover, vetch and daikon. Once grown, was blinded with scythe, so nutrients from all these plants returned to the soil, improving it.
In the first year, seeing that the soil had some conditions, we focused on the level of trees and planted 80 trees between rootstock, grafted fruit and auxiliary species. We had a ratio of 70-80% of deciduous over evergreen. The auxiliary trees are legumes which help fix nitrogen in the soil, for example, carob planted among other trees. They may also have phytosanitary properties, such as, elder.
In the second year, we are committed to increasing the diversity of the forest, planting more fruit trees, shrubs and lots of sacrificial trees. The latter, as tagasaste, are fast-growing trees, also nitrogen fixers, which we prune to provide organic matter at an accelerating rate, a technique known as "chop and drop".
Woods stories/historias del bosque