Moving Beyond the Traditional 7 Layers of a Food Forest

Are there more than 7 layers in a food forest? I think so and I'm going to share with you all why. But I also want your feedback. Is this a crazy idea? Or does it make sense? Is it interesting? I may write a full blog post all about this concept but I want to see what you all think first.

Before I outline the new layers I think should be added to the food forest model here is a brief overview of what a food forest is and the traditional 7 layers. National Geographic has a great quick video all about food forests that I highly recommend as a good intro to the topic.



In brief a food forest is a system that mimics the natural structure of a forest to grow an abundance of food, wood, medicine, etc. for human consumption. A food forest (aka forest garden) is the ultimate expression of working with nature to generate a useful harvest for your homestead.

The traditional layers are:

1. A canopy layer with large fruit or nut trees (support trees and timber trees could be here too)
2. A sub-canopy layer of smaller trees such as dwarf fruit trees (coppiced trees could be here)
3. A shrub layer for fruiting bushes but again support plants such as nitrogen fixing shrubs work too
4. The herbaceous layer for herbs (cooking and medicinal), flowers, vegetables, etc.
5. Ground cover as a living mulch which can be edible.
6. The root crops
7. And a layer consisting of vines and climbers

Each of these layers would blend together in a natural forest and a forest garden tries to mimic that. Though sometimes you may choose to keep it as an open woodland with greater spacing between the large trees so more sun reaches the ground for the lower layers.

Instead of calling these the traditional layers how about we call them the living layers--sound good?

My Proposed Addition to this Model



This is all building off of what I was talking about in this week's blog post about rewilding your homestead. In that post I talk about adding features such as snags (dead standing trees) to your homestead. I do this on mine by taking old logs and "planting" them upright.

For my day job I run large restoration projects across 4 counties in the South Puget Sound in WA. I have also done habitat assessments in Idaho and Washington for past jobs. Plus I grew up running through forests around the small rural Eastern WA town I grew up in. All of this has taught me that a forest is not just made up of the living elements such as plants and wildlife. The non-living elements such as rocks, woody debris, snags, etc. are a core part of a healthy vibrant forest.

So what does that mean for a food forest? Well these non-living elements tend to be ignored overall (though people are generally good about mulching). To help change that I propose these layers be added to the food forest model:

1. Large snags (10+ feet high and 1+ feet across)
2. Small snags (Less than 10 feet high)
3. The stump layer (Short and thick woody debris that mimic a stump)
4. Large woody debris (logs, root wads, etc. laying on the ground)
5. Rocks (both rock piles and individual large rocks)
6. Small woody debris (twigs, branches, etc.)
7. Mulch layer (leaves, wood chips, etc.)

The large snags might not always be safe in a food forest that sees a lot of traffic and they would be difficult to install. But if you have a large tree die then this could be an opportunity to cut it down to a safe but still tall height and remove the limbs. If large enough these snags are great habitat for woodpeckers, owls, and other birds plus other wildlife.

Small snags are easier and can be installed just like a fence post. I have added several of these to my homestead.



This is an example of a relatively small "stump" added to my in-progress food forest. The picture at the start of this section shows a small rock pile and here is an example of a larger one at one of my restoration sites.



Amphibians and reptiles love to hide in these rock piles. They can also capture a small amount of water and create a moist area below them that plant roots can tap into.

If you look at a forest floor there is a layer made up of logs, branches, leaves, etc. This layer to me is what truly defines something as a forest. The result is a fungal dominated system that is great for trees and shrubs. It is filled with life and also works as a sponge soaking up water and keeping the forest hydrated through dry spells. It also creates rich soil as it breaks down.



Here you can see one of my new planting areas in my in-progress food forest. I added a large log plus wood chips and fall leaves. All of this is to mimic a natural forest floor. I could add some branches and of course I need to add a lot more plants.

Each element in these layers would only provide a small benefit. But just like the original living layers of a food forest it is the interaction of them all together that adds complexity and diversity to the system. This is what can truly create a vibrant and abundant system.

Putting it all together



In this expanded model of a food forest there would be 7 living layers and 7 non-living layers. My view is that a forest is only truly a forest if it has at least a portion of these 7 non-living layers. From fungal systems to woodpeckers so much of the life of a forest depends on these non-living elements.

So what do you all think?

Please share your thoughts below I would love to hear from you all!

I love this idea!  

Bodies have support structures. Forests have non-living structural elements. It seems straightforward.

My question would be to what extent the items occupying the same non-living trophic layers could sub in for each other, or whether combining them could yield better results. For instance, are rock piles and stumps necessary together? In which ways would they be redundant to each other, and in which ways would they compliment? As in, would the airwell function of the rock pile keep the decomposing stump and root system more active than otherwise?

I like it. I think that I could see using, for instance, upright snags in my backyard as perches for local Red-tailed Hawks that prey on the overabundance of squirrels. In the same way that a rock pile will attract amphibians and reptiles to live there, benefitting a food forest with pest controls, so would habitat and natural infrastructure draw other biological controls.

Though landforms belong on your list, I think. What structural elements affect the living layers more than landforms that block out wind dessication and delay the progress of water over and through the soil?

-CK

There are expanded food forest layers. Like this that goes to 9 including aquatic/wetland, and mycelial/fungal



I think the mycelial/fungal layer is the often forgotten but also one of the more critical. Your idea of using nonliving elements as additional layers indeed as you mentioned helps this mycelial/fungal layer dramatically.

Along with mycelial/fungal, another aspect forgotten is microbial life in the soil. This is another critical yet forgotten aspect of giving the plants what they really need to thrive and survive. In fact the fungi and microbial life tend to work together with the plants in a very wonderful way. Trading and swapping things they don't need for things they do.

Interesting due to this the mycelial/fungal and microbial layer are sort of the bridge between the two sets of layers.

As for aquatic/wetland I think we often forget this due to how difficult it is to do for the more production oriented food forest designs. However there are some great ways to farm wetlands and aquatic areas like chinampas or even the all famous rice paddy. Starting to find ways to include these sorts of water features in with the food forest designs might be highly beneficial. Just as your 7 nonliving layers, the aquatic/wetland layer could be highly useful in rounding out the food forest design system.

Would soil constitution also fit? I'm thinking that there are places in the world that are missing a key element. For example, my area is low on selenium. Plants normally cope but animals frequently need to be supplemented. I've read of similar things on other continents or areas of continents. Sometimes planting dynamic accumulators are enough to solve the problem, but one might not plant them if they didn't recognize the problem.

I like Devin Lavign's post of the expanded forest layers and his comment about microbial life in the soil. That's an area which is getting much more attention finally! That said, Daron Williams suggestions of paying more attention to woody debris and rock piles will support microbial life. I'd be happy to just label that layer "assorted woody debris" just like we label "tree" but not exactly which trees, and leave the examples to explain further.

Jay Angler wrote: That said, Daron Williams suggestions of paying more attention to woody debris and rock piles will support microbial life. I'd be happy to just label that layer "assorted woody debris" just like we label "tree" but not exactly which trees, and leave the examples to explain further.

Geoff Lawton says in many of his videos "the forest grows on the fallen forest" and emphasizes how important woody debris is for the growth and health of trees.

Example:  https://www.youtube.com/watch?v=WwMl5hNzg1s

Chris – I don’t think having all the features are necessary but I do think a good mix is. Rocks and stumps and even logs to me all provide different and similar benefits. For example, I see evergreen huckleberries growing on stumps but I don’t really see them growing on logs. Perhaps that is because a stump rots differently than a log?

I debated landforms and I think those to me are separate from what I was imagining at least. I was trying to think of the elements that make a forest a forest. Landforms of course modify a forest but any one type is not necessary for a forest. But landforms can of course be used to benefit the forest—I would put them in a separate grouping. But having  a list of landforms and the benefits they provide would be beneficial for people designing a food forest.

Devin – Thanks for sharing that, I had seen that list before. I like that it mentions the aquatic/wetland layer and mycelial/fungal layer. The fungal layer is a defining part of a forest.

Good points about mycelial/fungal life and the microbial life. All that is very important.

The aquatic/wetland is interesting. A forest does not need those to be a forest but that does add more diversity and benefits to a forest. I would agree that this would be a great addition to a food forest where possible.

Jay – I’m afraid I don’t know enough about the topic of soil missing key elements to offer much on that.

As far as the woody layers I do think it is important to separate them at least to a point. Large woody debris (big logs and stumps) provide very different habitat from small branches. I would want to encourage people to include logs in addition to say chop-and-drop material and fallen branches. The original layer list does break trees into 2 groups—I was thinking about something similar for woody debris. Perhaps small and large?

Tyler – Geoff is one person that I see who does a great job with some of this. He always seems to just chop-and-drop instead of hauling the woody debris away.

But I do see a lot of people on YouTube with some great food forests but when you look they have no woody debris. No branches, no logs, etc. They have leaves and wood chips but they seem to remove the rest. I have seen some doing pruning videos or cutting down a tree and they just haul the stuff away.

Seeing those videos made me want to write about this. I also don’t see the non-living elements in the books on food forests that I have read or blog posts about the subject. Just seems to be missing from a lot of otherwise good information resources.
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Thanks all and great conversation! Please keep it coming! I think sometimes the whole concept of a food forest gets simplified a bit too much so discussing the non-living elements and other elements like water and landforms and soil is great!