Permaculture Designers Manual
CHAPTER 3 – METHODS OF DESIGN IN PERMACULTURE
Section 3.13 –
Permaculture and The Concepts of Guilds in Nature
The methodologies of Polyculture Design rely more on species interaction than on configuration, although both are necessary inputs to a design.
Thus, in designing for best (or most beneficial) species assemblies, we need to know about, and use, the concepts of species guilds and the co-actions of species.
In the natural world, we may often notice assemblies of plants or animals of different species that nevertheless occur together over their range.
Closer examination of such mixed assemblies often reveals a set of mutual benefits that arise from such convivial togetherness.
These benefits offer help or protection to the whole assembly (as when one bird species acts as “lookout” for another, or defends others from hawks).
When we design plant guilds, as we always try to do in a polyculture, we try to maximize the benefits of each species to the others. We can also add factors of convenience to ourselves, or which save us inputs of fertilizer or pesticides, as in the “apple-centered” guild described below.
A guild, then, is a harmonious assembly of species clustered around a central element (plant or animal). This assembly acts in relation to the element to assist its health, aid our work in management, or buffer adverse environmental effects (See Figure 3.12). Let us list some of the reasons to place species in association:
Figure 3.12 A Guild Assembly for an Idealized Apple Orchard
To benefit a selected species by:
Reducing root competition from (e.g.) invasive grasses; almost all of our cultivated food trees thrive in herbal ground covers not grasses.
Assisting pest control in various ways:
By providing anti-feedants (bitter or unpalatable browse or chemical deterrents), e.g. nasturtium roots provide root chemicals to tomatoes or gooseberries which deter whitefly. Many plants, fermented or in aqueous extraction, deter pests or act as anti-feedants when sprayed on leaves of the species we wish to protect.
By killing root parasites or predators, e.g. Crotalaria captures nematodes that damage citrus and solanaceous roots; Tagetes marigolds “fumigate” soils against grasses and nematodes.
By hosting predators, as almost all small-flowered plants [especially Quillaja, many Acacia species, tamarisk, Compositae (the daisy family) and Umbelliferae such as dill, fennel, carrot, and coriander] host robber-flies and predatory wasps.
Creating open soil surface conditions, or providing mulch; For example, comfrey and globe artichokesallow tree roots to feed at the surface (unlike grasses, which competes with tree roots), while spring bulbs (daffodils) or winter-grown wild Allium species, whose tops die down in mid-spring do not compete with deciduous tree roots in summer dry periods, nor do they intercept light rains.
Providing free nutrients: woody or herbaceous legumes fix nitrogen or other essential nutrients via root associates, stimulate soil bacteria or fungi, and benefit associated trees.
Clovers; trees such as Acacia, Casuarina, and Pultenaea; sugar-providing grasses (sugar cane); and high humus producers (bananas) all assist orchard species. Many can be slashed or trimmed to give rich mulch below trees or between crop rows.
Providing physical shelter from frost, sunburn, or the drying effects of wind; Many hardy windbreak species of equal or greater height, both as edge windbreak or in-crop crown cover exclude frost, nullify salty or hot winds, provide mulch, and moderate the environment towards protecting our selected species. Examples are borders of bamboo, cane grasses, Casuarina, hardy palms and tamarisks. In-crop shade shelter of legumes is needed by such crops as avocado, citrus, and cocoa or coffee (or any crops needing partial shade). In-crop trees can eliminate frost effects in marginal frost areas.
To assist us in gathering:
Culinary associates: it is of some small benefit in detailed planning to keep common culinary associates together (tomatoes with parsley and basil; potatoes with a tub of mint) so that we also gather them together for cooking, salads, or processing (dill with cucumbers).
Thus we reduce work.
Dill and applesauce go well together, raw or cooked, and dill is one of the Umbelliferae that host predatory wasps below apple trees.
Specific animal associates of a guild:
We have made reference, in pest control, to host plants. These can be best specified by observing, researching, or selecting plants to host quite specific predatory wasps, lacewings, or ladybirds.
Vertebrates that assist our selected crop species are:
Ground Foragers, e.g. pigs or poultry specifically used to clear up the fallen fruit that host fruit or larval forms of pests. Foragers can be run in orchards for that relatively short period of the year when fruit is falling and rotting. or they can be used to eat reject fruit and deposit manures.
Insectivores: birds in particular that search bark crevices (woodpeckers, honey-eaters) for resting larvae and egg masses. To encourage these, plant a very few scattered flowering shrubs and herbaceous plants such as Kniphofia, Banksia, Salvia, Buddleia and Fuschia. All of these provide insect and nectar foods for insectivorous birds.
Mollusks control: snails and slugs are almost totally controlled by a duck flock on range and several large lizards (Tiliqua spp.) also feed primarily on snails. Ducks can be ranged seasonally (autumn to spring) in plant systems and in summer on marshlands. Ducks will eat seedlings, so that appropriate scheduling is essential.
Guard Dogs: for deer, rabbits, and other vertebrate pests. A small number of guard dogs, fed and kenneled in orchards, are sufficient control for fox predation on orchard poultry foragers. Such dogs, reared with domestic poultry, do not attack the flocks themselves.
Hawk kites: suspended over a berry crop, or flown light model planes over an extensive grain crop deter all flock-bird predators of the crop and are more dependable than natural hawks. They need to be removed when not needed, so that birds do not get accustomed to them.
These are just part of the total guilds. Every designer, and every gardener, can plan such guilds for specific target species, specific pests and weed control, and specific garden beds or orchards.
ANALYTIC APPROACH TOWARDS SELECTING A GUILD
A guild of plants and animals is defined here as a species assembly that provides many benefits for resource production and self-management (more yields, but lower inputs).
In general, the interactions between plant and animal species are thus:
Most species get along fine; this is obvious from a study of any complex home garden or botanical garden; perhaps 80% of all plant species can co-mingle without ill effect.
Some species greatly assist others in one or other of many ways. Positive benefits arise from placing such species together where they can interact (10-15% of all species).
A minority of species show antagonistic behavior towards one or more other species.
This in itself can be a benefit (as in the case of biological pest control) or a nuisance (as in the case of rampancy or persistent weeds or pests).
Perhaps as few as 5% of all species act in this way.
Now, to give the above classes of interaction a more useful analytic structure, we will allot symbols, as follows:
+ : this is used to indicate a beneficial result of interaction, with a yield above that of some base level (judged from a monoculture or control crop of the species).
o : this is used to indicate “no change” as a result of interaction, on the same basis.
– : this is used to indicate a reduction in yield or vigor as a result of interaction with another species.
Thus, for two useful species (each selected for a useful product), we have the simple tabulation of Table 3.5, which gives us all possible interactions.
The array is such that only three interactions benefit us, three are neutral and three are antagonistic in effect.
By grouping scores, we can analyze for beneficial effects in our interaction table and act on these. However, because of the vagaries of weather in any given year, many times a peasant farmer may accept a (- +) effect just to ensure that he at least gets a crop, even if it is of the “losing” species.
It is always safer to mix or complicate crop than to pin hopes on a single main crop. In fact, be guided by analyses but study reality!
STATES OF ACTION
In common usage, COACTION implies a force at work: one that restrains, impedes, compels, or even coerces another object. INTERACTION implies reciprocal action: two things acting on each other.
This is an important distinction.
A final category is INACTION, or an absence of any detectable action.
We cannot at this point guess which state applies, but when we put two species together, there are these possibilities:
- One acts on the other (co-action or unilateral action);
- Both act on each other (Interaction or mutual action);
- Neither act (inaction or neutrality).
It would seem probable that In the case of (+ +) and ( -) we have mutual action or interaction. In the case of
(- o), (o -), (+ o), (o +), (+ -), (- +) one only needs to be acting, a form of co-action. In the case of (o o); neither acts, no effects appear, and both are inactive insofar as our measures can detect.
We need to observe and perhaps analyze each case, but It does seem probable that such states of action apply. Some such states can be named and examples given, for instance:
A. Mutual Action States
+ +: This is called symbiosis, and is common both in nature and in society. It is a “win-win” situation ideally suited to guild development. An example is the mycorrhizal associates of higher plants, where mutualism or fair trade occurs between a plant and its root associate.
There are forms of chemical warfare in both plants and animals.- Haskell (1970) has coined the word synnecrosis (The Science Teacher 37(9) Supplement), and it is obviously uncommon. War is our best example of a “lose lose” situation, but there are also battles between plants for light, nutrients and space.
B. Single Action States
– o: Haskell calls this amensalism. It hurts the actor, not the other. A butterfly attacking a rhinoceros would fit, or a wasp parasite “glued” to a tree it attacks, as is the case with some pine trees and Sirex wasps.
o -: Called allolimy by Haskell, it leaves the actor unaffected but hurts the other, e.g. a walnut tree beside an apple tree yields well, but the juglones secreted by its roots act to kill or weaken the apple tree. In the same way grasses act to weaken most deciduous fruit trees.
+ o: Termed commensalism. Even though the actor benefits, the other remains unaffected, e.g. an epiphyte attached to a sturdy tree, such as vanilla on a coconut trunk.
o +: Called allotrophy by Haskell. The actor is unaffected, the other benefits. Examples are a teacher and student relationship, or a charity where one hands on surplus goods to another person less fortunate.
+ -: Called parasitism, the actor benefits, the other loses if the actor is the parasite. All pathogens and parasites tend to weaken or take from the host.
– +: Self-sacrifice. The actor loses. This is the reverse of parasitism, and a better word might be self-deprivation to help others. This is often seen in nature, mostly as individuals helping members of the same family or species. Medals are awarded for this in human society and we ca11 it selflessness or even heroics.
o o: Neither one acts. No one is hurt no one wins. Neutrality pacts may achieve this result in society, or we observe it commonly in nature.
There are critical areas in nature (water holes salt licks, grooming stations) where antagonistic species agree on neutrality. In fact, many plant species appear to be basically neutral in behavior.
Such analyses suit two-species interactions, but where we depart (in the designed system) from nature is that we may value (in the sense of obtaining a yield from) only one of these species. Let this be species A in Table 3.6.The other can be a weed or a species such as Lantana, which we might wish to eliminate. In this case, we can set up a matrix as diagrammed in Table 3.6.
This is a very necessary type of analysis for selecting useful plants that will eliminate or weaken an unwanted weed species. All such analyses can be made using plant /plant, animal/animal, or plant/animal pairs.
How do we observe co-action? This is quite simple in the field, providing there are plenty of examples to score and we have set some criteria to score by.
For example, take a town or area with a great many trees planted in the backyards.
Select any one of these species for criteria, say an apple, then decide on how to score, e.g. (in compounds with apples and other species of plants growing):
+: apple tree healthy, bearing very well, not stunted or over-vigorous.
o: apple tree healthy, in fair order, bearing.
-: apple tree bearing poorly, sick or dying.
x: no apple tree in this yard.
Then, we draw up a co-action matrix on a piece of paper, with the “apple” score at the top and “other trees” down the left side (Table 3.7).Tally the scores by walking from yard to yard.
We quickly see that where there are walnuts, apples are sick or absent (o -). However, healthy apple trees coexist with mulberries and Acacins (+ o) and (o o). Ideally, we use a similar scoring for each species of other trees, so that our co-action results score the same criteria for walnut, mulberry, and Acacia that we score for apple.
Additional field notes are useful.
Healthy, untended apple trees often have quite a specific understory of spring bulbs, comfrey, clover, iris, nasturtium, etc.
This too should be noted as we go. I have, in fact, carried out such analyses, and some of the results will be used as a real example in the next section.
BUILDING UP GUILDS FROM CO-ACTION ANALYSIS
If we wish to construct a guild, then we need to bring two or more species into close proximity where we can judge the effects of one on the other. If we have a (- -) result anywhere, we might be able to intervene with a third or fourth party which we can call an arbitrator, a buffer, or an intervener.
Apple next to walnut produces (- o): not desirable; the apple sickens or dies.
Apple next to mulberry produces (+ o): a good result.
Mulberry next to walnut produces (o o): mutual inaction.
Thus, apple then mulberry then walnut gives us (+ o o). By this intervention strategy, we have, in effect, cancelled out the (- -) and have a net benefit in a three species array. That is, we can use several two-species results to achieve a better result with three species, which goes beyond accepting (fatalistically) the primary conflict. Here, a mulberry is the intervener or critical species or element in conflict resolution. We can take this further again by examining yet other co-actions:
Acacia next to walnut gives (o +)
Acacia next to mulberry gives (o +)
Now, apple-mulberry-Acacia-walnut gives us (+ + o +), which is much better again. So we proceed to isolating and arranging guilds to maximize benefits and eliminate conflicts. This is part of the skill of planning strip or zone placements of mixed species.
THE ROLE OF CONFIGURATIONS IN GUILDS
Here, we have to consider placement of interactive elements.
Obviously, there is a commonsense close spacing for many plants and machine components, but as the distance between living components widens, we can never be quite sure that chemical or behavioral interaction ceases.
Consider the case of two territorial birds, displaying or calling a mile or more apart. To us, they appear as individuals; to each bird, the other is in dear interaction.
There is distant interaction, too, via pollen or spores in plants, and perhaps even by gaseous or chemical “messengers“.
This is certainly true of some mammals, so that effects of one on the other can be passed on by a sense of smell, even though they are not nearby at that time, e.g. urine marking territory.
The great whales may well be communicating by sound around the whole globe.
Configuration in planning a guild with intervening species between hostile (- -) species, comes in assessing the distance across the interaction boundary that the effect takes place, and in then arranging the guild species to obtain a maximum of (+ +), (o +), or (+ o) effects.
For example, we find a (+ +) condition with legume/grain or fruit-tree/tree legume interplant’s.
We know that the effect, for grains, extends from 1.5-2 m into the crop; thus for a configurational design, we can spiral or strip-plant these two species for a total positive edge interaction effect in crop.
Such careful guild analyses and configurations are the basis of species planning in permaculture.
For more critical geometric analyses, see such texts as: