Site
Map 
ResourcesPenrhos
Home Page
Site
Map Resources
back to my conributions to the British Permaculture Designers' Teachers' Handbook
[This was my original version and contains greater detail and clearer arguments. However, it proved to be to long for the format we had chosen. The final version is here
Quick contents
REGENERATION [draft]
Chris Dixon
Introduction:
I think and feel that natural regeneration provides us with powerful models for our design work. Since 1986 I have been privileged to observe on an almost daily basis the process of natural regeneration and have found it hugely inspiring, encouraging and empowering. The patterns unfolding in regenerating systems have applications not only in environmental design but also community and personal development. Most of Britain was forested in the past, (I have seen estimates ranging from 80-97% forest) and that's what most land is trying to turn into today. The only reason it doesn't turn back into forest is due to the limiting factors that apply on any given site. Initiating regeneration is simple and generally requires only the removal of those limiting factors.
1. If I am teaching from my home I will show students the regeneration project on site. I find this to be an incredibly powerful teaching resource. The site can largely tell its own story and it is only necessary for me to provide a commentary on what people are looking at, answer specific questions and point out examples or evidence for the main points.
2. If I am teaching in another locality I will try to find examples of regeneration nearby. This is usually straightforward as nature is always trying to colonise everything; possible sites include any so-called derelict land, railway cuttings, building sites, abandoned quarries, overgrown gardens, the cracks between paving, roadside verges etc. etc. Once students' attention is focused upon the concept of regeneration they will find many examples.
3. As well as site work or if a site is not available I will use a set of slides to show some of the stages in the regeneration process. The slides picture the progress of my own regeneration site and also cover other examples of regeneration in different situations.
4. I will also generally make some form of presentation of succession on a white or black board. I have used an Ice Age model, (see illustration), which shows the movement from mineral rich but organically poor soils after the ice age through to high forest. I draw this as a curve and include quick sketches of plants, animals etc. I usually get the students to drive this presentation by asking what comes next in the succession. There are no "wrong" answers here as I can fit any contributions within the basic curve and keep prompting until gaps are filled. Great detail on species and precise orders of succession are not crucial here. The presentation allows me the opportunity to make the main points if they do not arise from the group.
5. Lists of succession can be obtained from various sources, (see bibliography below). I use my own generated through observation of my own site. I point out that there is no single line of succession, that on any site the process will be complex and flexible depending on the limiting factors relating to a specific site and how much intervention is made. Also, after a few years, examples of all stages of succession will be present at the same time, particularly if paths and clearings are maintained, (say by grazing animals). The list I use as the basis for a presentation is as follows:
There are a number of points to be made regarding natural regeneration; these are not all of them.
The main point is that all land is dynamic rather than static and contains patterns for its own evolution. These patterns relate to soil types, aspect, slope, drainage, seed resources etc. etc. It is generally not necessary for us to be concerned with this as the land will sort itself out, making good any deficiencies in terms of nutrients, increasing water retention, building shelter, etc. etc.
The above three points provide us with the essential basic criteria for measuring the sustainability of an environment or site; i.e. is the site storing more water each year or less? Is soil building taking place or is there an annual loss? Is the bio-diversity of the site increasing or decreasing? These questions can and should be applied to our environmental design in general and not just regeneration. I see these three points as fully interconnected but I present them as a prioritised list; current attention tends to focus on bio-diversity alone so I point out that without water or soil, bio-diversity alone will not generate a sustainable system.
The primary and greatest storage for water in Britain is in the soil; this is a far greater reservoir than any we could construct. Regeneration results in leaf trapping, (which does not take place on grazed pastures), the appearance of soil improvers, (e.g. gorse) and a general increase in bio-mass, part of which is deposited on the surface annually and part of that is in turn incorporated into the soils. Coupled with increased root penetration as forbs, shrubs and trees take over from grasses we find a general increase in the water storage capacity of the soils; dry areas hold more water. The increase in plant material above ground slows and eventually stops run off and increases infiltration of the soils and through flow. The through flow recharges the water table, springs and rivers.
It should be clear from the above that soils and water are not really separable; as well as the increased water capacity, the regeneration process inevitably improves soils. I point out that given sufficient seed sources regeneration will tend to make good deficiencies in soils. This is a direct consequence of natural selection; i.e.. in acid soils plants which do well will be extremely good at grabbing any available calcium, possibly from deeper levels. As these plants die the calcium will be made available to other plants. Gorse is a good example here; it gains calcium from the subsoil and returns the element to the top soil when it dies thus making the subsoil more acidic and the topsoil less acidic. I point out that gorse is a nitrogen fixer, (as are the trefoils and St. John's Wort), that bracken accumulates potash, (potassium) and that the increased ground cover and shrub layer on regeneration sites provides good bird habitat and that birds accumulate phosphates in their droppings. Thus the three primary plant nutrients are provided for and recycled through the regeneration system. I usually add that this should give us confidence to accept that the regenerating natural system will similarly aquire and recycle any other essential nutrients or trace elements without us having to worry to much. I personally believe that soil deficiencies are generally not immediately significant in terms of limits to yields; i.e. there are usually more obvious limitations that we can deal with.
Inherently connected with water storage and soil building. I sometimes draw an S curve to show how diversity increases more and more rapidly and then gradually slows down but never really stops. Again, in most situations this will look after itself. In the light of the Rio summit and Local Agenda 21 I usually talk about the importance of maintaining local bio-diversity; I have good examples on site of local self sown birch trees and container bought imported birch trees, (from Holland via Shrewsbury). The benefits of the locally adapted trees are very obvious. A further point is that we should observe the existing system carefully before undertaking regeneration. It may well be that there are important flowering species in the existing meadow or that a meadow itself is ancient and represents a healthy, useful system. in these cases I would consider carefully whether to maintain clearings, (by the controlled use of animals if possible rather that machines). This means that regeneration will add in more species without loosing the ones that are already there, (i.e.. through increased shade).
My observation of regeneration led me to consider the limits to yield in natural systems. At present I see this as something like an onion with layers of limitations which have to be peeled away in an appropriate order. Each time a layer of limitation is removed, another limit is revealed. This approach can obviously also be applied to designed systems. The process involves identifying the primary limit to yield, removing it, then identifying the subsequent limit and removing it etc. etc. It is important to remove limits in order; for example, letting in more light or adding seed before removing grazing animals will not work. The order of limits will vary from site to site but I usually present the following list as a guide. Students may come up with others which I then add in.
a) Grazing animals and agriculture
The primary limit to regeneration in Britain. The forest germinates and begins to grow every year but gets eaten or ploughed in. Solution: remove animals or stop ploughing.
b) Lack of available seed sources
For regeneration to move fairly quickly on large fields with no mature seed trees, additional seed can be distributed. Keeping in mind local bio-diversity the collection of a proportion of seed locally would be useful, (ideally from trees of proven local provenance). However, we should bear in mind the longer term management of the regeneration site and be ready to include useful exotics in our additional seed.
c) Tenacious species
These might be rhododendron, bracken, western hemlock, rye grasses; the tendency is towards monoculture. This is an ongoing challenge; I believe that the challenge is to generate products and markets for these materials so that the management of regenerating systems generates yield. A good example here is bracken which can be incorporated into large or small composting schemes. Some tenacious species in some situations may require radical treatment such as the one-off use of a chemical. Careful observations may lead to useful solutions; for example, rhododendron does not appear to like growing under sycamore perhaps due to the dense shade but possibly due to nitrogen toxicity, (from aphid droppings). I present possible long term solutions to give students a sense of the timescales we should be including in our designs. E.g.. cut swathes through rhododendron stands and plant with sycamore at high stocking rates. After fifty years coppice sycamore and underplant with trees of proven local provenance.
d) Lack of light
Unthinned or undermanaged woodlands, particularly monocultural conifer plantations. Thin the trees and let more light in.
e) Too dry
Add in simple swales, contour plough or rip, add surplus organic materials.
In effect, the regenerating system can be steered toward any of the zones; i.e.. we can leave it to itself and move towards wilderness or we could high prune trees and add in more timber species to move towards forest. We can capitalise on the nutritional content of certain plants and steer towards animal forage systems. We could favour existing soft fruits and add in others plus hard fruits to create orchards or we could include a simple dwelling to allow a person to generate an intensive food garden. Steering requires cycles of thoughtful, prolonged observation followed by small scale experiment. A simple example I provide is that of pulling bracken and using it as a mulch around trees or gorse or soft fruits. Depending on which we mulch we can steer the system towards one or more of the zones. (I remind people here that zoning is related to the ease of giving attention so its pointless trying to steer the system towards orchards for example if there is no access or no-one on site etc.).
A further point is that the regeneration process can be halted at any stage through management if this is the desired long term design. The obvious one is that animals, especially sheep, can maintain the process at the pasture stage. Another example is that goats managed with electric tape fencing, tethers or Spanish martingales can create scrub fodder systems. Similarly, horses, which prefer grasses, can favour forbs and even tree regeneration if their numbers are low or similar strategies to goats are employed. We have oak and hazel self seeded into our pasture.
The patterns of succession in regeneration natural systems can provide us with useful strategies in our general design work. This has particular use in broadscale systems, rolling permaculture or where funds or time are limited. For example, on our own site we have areas where year one we plant and spot mulch trees, year two re-mulch and use some sheet mulch to generate clumps into which we can plant soft fruit cuttings, year three re-mulch, scatter associated seed, harvest soft fruit etc. etc.
I point out that observation of the evolving system is vital and that this provides us with our first and most valuable yield, information. This requires interventions, (access, paths etc.), which can actively encourage further diversity and regeneration. A path, for example, generates a strip of more compressed soils with two edges; that is, it creates differences or different niches which nature will fill. Interventions regarding tenacious species should be assessed carefully. Often what appears as a problem will turn out to be a temporary phenomenon. For example, some trees, particularly Rowan but also oak and birch, can outcompete bracken in some situations so it may be unnecessary to harvest bracken under them as they will shade it out in time anyway. Where an intervention is made I encourage students to think of a use for the material prior to making the intervention. Bracken for example can be used as mulch on the regeneration site to favour sapling trees or it can be removed and used as mulch elsewhere or incorporated into a composting system.
All the principles can be demonstrated to good effect:
a) Work with nature not against it
This presupposes that we understand something of what nature is trying to do in the first place. The observation of regenerating systems provides us with direct experience of natural processes and the opportunity for us to become involved in that work.
b) maximum effect for minimum effort
The recognition of the primary limit to yield, (e.g. grazing animals), leads us through the minimum steps necessary to maximise yield.
c) everything gardens
Every plant that appears during the regeneration has some part to play in the process, whether providing shelter, protection, grabbing a trace element and making it available to other species. Every insect bird and mammal is gardening part of the system in some way; the meadow ants build new heaps once the sheep have gone and provide a minute area of tilled soil where very specific annuals have the chance to grow; fallow deer thrash growing trees in the rutting season and in effect create coppice systems that they can still reach to browse. Every interaction we make with the system is gardening, walking generates paths, moving a bramble runner to one side. It may take some thought for us to recognise how gardening is taking place in any given instance but this is time well spent.
d) the problem is the solution
Bracken becomes a useful mulch or compost additive. Browsing deer keep open paths and clearings thus maintaining pasture species.
e) the yield of a system is theoretically unlimited
The regenerating system demonstrates increasing yield. In most situations, increasing biomass is the most obvious increase initially, (it all gets bigger). The increase in plant surfaces increases the area available for interactions with the atmosphere and climate. Increasing amounts of energy are trapped and recycled through the system or stored in soils as fertility. As mentioned above, the yield can be represented as an S curve which gradually slows down but never stops. As gardeners we can always add another species if we choose or make small interventions to increase cycling of nutrients or trapping of energy.
I generally broaden regeneration out at some point. I remind people that we are dealing with a holistic system which includes both matter and consciousness. In the same way that environments and soils have become eroded and degraded, so too have we as individuals and communities suffered erosion and degradation. I present the idea that regeneration of individuals and communities can be approached in the same way as that of environments; that is, we can think of ourselves and our communities as having similar tremendous powers of regeneration, able to recover from enormous damage, heal ancient wounds, re-create our natural diversity and abundance. Also, as with regenerating environments, this process is both easy to initiate and entirely appropriate; like land we are dynamic and will inevitably move in the appropriate direction as limits are peeled away. Like land, the identification of the key limiting factors operating on individuals and communities is essential. These limits need to be approached in a specific order if they are to be successfully resolved. I believe that as with land, regeneration is part of our very nature and requires only the briefest opportunity to grow and flourish.
There are a number of concepts or topics in Permaculture Design which are particularly suited to the communication of the holistic perspective; that is, concepts which permeate the ethics and principles. It should be clear from the above that I feel and think regeneration to be one of these key concepts in Permaculture Design.
1. To be technically precise, in scientific circles, the term regeneration is used to describe systems being colonised by native species. Revegetation is used to refer to growing systems that include both native and exotic species. I have used the word regeneration in a more general sense.
2. I point out that regeneration is not always appropriate. For example, species rich pasture can represent a valuable sustainable system in its own right where soil building is already taking place. I emphasise the importance of good surveying and species analysis before undertaking regeneration, (or any other intervention for that matter).
3. I am indebted to Phil Corbett for first making clear to me the similarities between erosion of soils, individuals and communities, (1991).
back to my conributions to the British Permaculture Designers' Teachers' Handbook