Function stacking means using elements that perform multiple functions and also employing several elements for each specific function.

 

Stacking functions designate the concept of planning elements and areas (space) to perform the most services for us with the least possible input (beyond the establishment phase). 

It concerns multiple usage and purpose of elements, for the biggest possible yield related to time and energy; at the same time, beyond the initial phase, we apply self-regulation, by letting the spaces themselves do some of the work.

From a Designer’s point of view, each element used in stacking ideally performs multiple functions, with the aim of increasing the efficiency of a space, while adding to resiliency by creating redundancies.

These statements stand true for professionals and the public, but applying them to a particular project might require an in-detail approach. For the aim of facilitating comprehension, I’ll address a few common topics encountered in permaculture projects at different scales.

1. Appropriate element placing for a specific function

Let’s take a simple example to base the topic on: imagine you’re dealing with mosquitos in your area; this is obviously something you can affect on your site, but the issue will not be resolved so easily. Different species of mosquitoes have adapted to all kinds of environments, and microclimates. Their life cycles, especially those of the larvae, are so fast that it’s impossible to have any effect on the population by using only one particular technique; so stacking functions is actually recommended in this situation.

After identifying to areas most impacted, you could choose among the following techniques:

• installing bat boxes to attract these prolific hunters that are capable of predating up to 800 mosquitoes per night
• placing small-scale water points to attract insects such as the dragonfly, a marvellous daytime aerial guard
• If you have water pooling naturally on your property, why not create an actual waterhole by deepening the hole, in order for it to host fish?

If the water volume is stable, and the cavity is deep enough (at least 0.8 m / 2ft 8’’), fish will probably survive through the seasons, and provide an important function as they will eat mosquito larvae, as well as adults

• frogs are attracted to the habitat, will move in on their own, and will complement the fish, by also patrolling the land area around the water hole
• you can improve the overall water quality by using mugwort (Artemisia Vulgaris), which impacts the larvae’s development, thus reducing the actual numbers that reach adulthood

2. Obtaining multiple yields (functions) from a particular element or space

Staying on the same subject, and thinking of elements that will indirectly benefit from the techniques mentioned above, we arrive at interesting situations:

• bats will also eat some of your fruit; that is regarded as a negative, but in fact, it is relative. Harvest-wise, you will have less fruit but you will not have to perform a time and energy-consuming task (killing mosquitos). There will be less disease spread, not to mention the comfort level of users 
• bats will also pollinate certain flowers and fruit, helping increase the actual yields; they will disseminate the seeds of everything they eat, thus enriching the yields, and there is an argument to be made whether they actually increase the effective yield of the system, over time
• their manure, known as guano, is a very valued resource; its (commercial) value will only increase in time, as super phosphorus reserves will dwindle worldwide, and we will have to depend entirely on living resources (please hyperlink to “future” blog )
• multiple water points, spread across the landscape, will also benefit insects and wild birds; the presence of the latter will also, indirectly, decrease the mosquito populations
• water holes are hubs for biodiversity, even if you don’t make other arrangements beyond the establishment
• plants, insects, and other life forms that are attracted to water can also represent fish food, thus supporting even further the initial desired function
• frogs are featured on culinary menus in some parts of the world, so that is a potential yield, on a regular basis even, once established
• the use of mugwort, in appropriate doses, will actually improve the health of domestic animals, as well as that of wildlife; that is a desired implicit function that will fuel the evolution towards resilience and regeneration

3. Creating beneficial interdependence 

As some of the above content has already started pointing towards, the connections are multiple; even those which are seemingly detrimental to certain yields, such as bats having an impact on harvests of fruit or other vegetation, they are not actually a net negative. The intervention of certain elements increases yields directly and indirectly, and over large periods of time.

• As bats will consume various resources, they are turning those resources (both positive and negative) into a net-positive resource, one that would otherwise be impossible to obtain without great expenses: guano. This will be highly useful for the fertility of the overall project.
• The bats eating insects and fruit will not be limited to the perimeter of the project only; that in itself is a beneficial exchange, both inwards and outwards. More and more plant species will be propagated, thanks to the manure, leading to diversity at several scales.
• In a later phase of the project, guano can be traded with other projects nearby, or commercialised; in an even simpler scenario, other bat boxes will be built where needed and the abundance will follow, for a very low input of energy 
• As an alpha insect predator, dragonfly populations are endangered currently. Helping it encounter favorable conditions will bring a boost to biodiversity, and to natural succession. The waterholes will become much more than just a technique to deal with a problem.
• Frogs and fish represent protein biomass that is much easier to grow than other crops, and in this particular case, you’ll be transforming undesired or non-edible resources (insects, water plants, larvae) into food. 

4. Stacking function in time – creating a succession

This particular function of Permaculture has also been addressed, at least partially, in the previous topics. Starting with the manure of bats, resources are cycled through the system and into the system at a faster rate; the product is a rich fertilizer that can be collected from the bat boxes in relevant quantities, and be used according to needs.

If left unharvested, natural succession will take place, with the seeds that the bats have eaten, germinating where they fall on the ground. Water points are hubs of diversity that push the project forward; the multiple interactions all trigger their own series of events.

Attracting insects and birds alike, this imports another “harvest” of seeds that have passed through the guts of the birds. We can see an expression of this complex phenomenon underneath power lines, or fences, where the vegetation is more diverse and richer than elsewhere.

For larger bodies of water, a potential sequence has waterfowl moving in; these will most likely bring fish eggs, glued to their feet. As the in-water population increases in diversity, new predators will move in and bring their own range of inputs or outputs.

5. Creating the conditions for interactive diversity

 Until now, we’ve only addressed possible sequences stemming from dealing with a problem (mosquitos) in a holistic way. The accumulation of solutions will not completely eradicate the said nuisance, but it will limit it greatly, and also keep it in control, through virtuous cycles.

More importantly, what designing elements into the system accomplishes is triggering a series of events that complexify the project, moving it in a certain direction. For the sake of taking you through sequences of events, we’ve only addressed a problem that is quite common, in any type of natural initiative. Imagine then what else can be done when actually building around a productive element.

 

Taking an apple tree as an example, Design thinking can begin by dealing with possible issues or diseases: 1. fungi/mold that might affect the leaves, 2. worm or insect infestations, 3. fruit being eaten by birds. Some of the solutions could come in the form of 1. cutting lower branches to avoid water from rebounding onto the leaves. 2. planting flowers in the understory to attract insect predators and 3. cutting branches that are too tall. All of these solutions, although requiring energy or resources, create opportunities for different elements; some might already be present in the project, and some might not be. Taking one example from above, planting flowers to attract insect predators will not accomplish that singular goal; it will also provide nutritional alternatives for birds, and small animals, enhance the aesthetics of the project or, at the very least, produce biomass. 

 

Adding to this library of possibilities, one of my favorite things to do is actually start from the elements already present on site, and build on that. On a recent project I coordinated, we were aiming to create enriched conditions for planting a food forest, starting with fruit trees. Lacking specialized support species, I identified native pioneer trees (or even successional trees) already growing on the site as seedlings and proceeded to mark them for transplant.

The digging of swales was accompanied by a sequence of adding a random collection of vegetation on those swales, as support species that aimed to move the project forward. Each of those volunteers (oaks, narrow-leaved ashes, hawthorns, black locusts) would perform a successional function in this “random” support assembly. Their match to the long-term project might not be “perfect”, but by building on what is on-site, our energy audit is actually very high. As the swale evolves, we will decide later what species we are to favor; the next step, in spring, is to introduce another series of more productive species (most probably berries). At that point, we will treat the successful transplants as tutors (for the more sensitive elements), and allow them to indicate which spots are more fertile. If some prove to be “too” prolific, they can be chop’n’dropped, feeding the fungi that are so important to the climax species.

 

In conclusion, by working with dynamic elements, we can accomplish a lot more than just establishing a food forest. At each step, something new can be learned, from the interaction with natural elements. One by one, productive plants are introduced, and volunteers find their niches as well. By combining elements and functions, new opportunities arise and we’re given the chance to extend our thinking beyond the initial prognosis. Overall, by aligning with how Nature works, we grow as co-designers of interactive ecosystems and become versatile stewards of the land. 

 

Continue reading: Guild layers and Functions: https://vinepermaculture.com/guild-layers-and-functions/