PERMACULTURE
EVALUATION
CENTRE
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240 The effective power to change systems is amplified when we act cooperatively with other agents
241 A common problem is doing too much too quickly – need to identify how to get maximum leverage. Excessive intervention in natural systems is often a mistake. In attempting to fix something , we may damage another system that is working perfectly
242 The ways in which species, ecosystems and whole landscapes develop resilience to large destructive forces is a central issue in ecology and, by conscious design, in permaculture
Human society has had to maintain a high degree of flexibility in the face of natural environmental change and social change. Annual grain agriculture and grazing is easier to restore after an invasion or war than ancient managed food forests.
243 In the tropics temporary structures are better than ones that are permanent or designed to be durable – list
Half hearted attempts at durability can be costly and worse than a renewable solution
Natural weathering and replacement vs applying paint, oils, etc
244 Recognise that use of buildings will change over time – avoid embedding aspects liable to change into the permanent structure
245 Classic ecological succession
Crop agriculture = herbaceous weed phase
Grazing pastures = grassland
Marginal and abandoned land = pioneer species and fast growing trees
Very little climax vegetation
This is a useful model even if not universally applicable – can predict succession forces expected to operate eg forests of light demanding pioneer trees provide an environment for succession to shade tolerant trees spread by berry eating birds, but they do not provide a good environment for regeneration of their own kind
246 This influenced design succession in permaculture : if more needs provided from later successional stages dominated by perennial plants, especially trees, then our cultivated ecologies would be more ecologically balanced and resilient to seasonal variability than those based largely on annual crops
An understanding of succession dynamics is essential. Observation is key to using succession.
247 The role of animals in preventing or steering succession is often ignored or misunderstood eg close grazing helps thistles to persist which would otherwise be crowded out by perennial grass
248 The idea of energy and succeesional hierarchy flowing from plants to herbivores and on to carnivores is a new way of thinking about nature for many people. Food and habitat are created for animals and humans by the slow moving processes of plants
249 New ‘pulsing’ concept for growth and succession in an ecosystem – diagram
251 Pulsing agricultural ecosystems: cell grazing, pasture ley cropping
252 Tropical slash and burn – was OK with 20y or more before recultivation – now too much pressure on declining areas of forest
The use of fire, grazing and cultivation to provide a pulse of high yield between longer phases of biological rebuilding was more fundamental to human success than annual crop agriculture. Used incorrectly though these techniques produce land degradation – it’s easy to slip back to a pioneering mentality.
253 Sheet mulching: good use of undervalued waste as long as it’s available but not likely to be the case for ever. Also, balance of soil deteriorates if covered by organic matter at much higher densities than litter present in a natural ecosystem. Better to move location of growing plots, gradual succession to fruit trees and shade tolerant perennials, more intensive soil management methods with carefully selected and measured applications of minerals, modest mulching, light surface cultivation.
254 Once a food forest is established, need to make space and light for most valued annual vegetables
Four Phase model of Ecosystem Change
* Conservation: long lived steady state climax
* Release: short pulse of disturbance
* Reorganisation: unstable, with potential to flip to less or more productive system. Risks from loss of mineral nutrients, severe weather, ecological invasion – a new ecosystem that is able to use the available resources better
* Exploitation: pioneer species catch and store energy
256 Socio political cycles as a pulsing system
Last 20y: intense pulse of economic activity that consumed social and economic capital that had accumulated since WW2. So called productivity was built by cashing in public assets. Short term profit considerations tended to dominate.
257 The large scale pulse of fossil fuels
We have consumed the easy to find half of oil reserves. So rebuilding of social and cultural capital must occur in the context of declining net energy availability, in parallel with rebuilding natural capital in our landscapes. At least the crisis has alerted us to the dangers and the possibilities
260 Might evolution proceed by diverse processes in jumps, and therefore be analogous to the pulsing ecosystems model? New lifeforms evolving from such a pulse, like disease organisms or rampant weeds could be a threat – or an opportunity
261 It isn’t true that most ecosystems are fixed and ancient. Although species may be remarkably durable and persistent, the relationships between species and the physical environmental factors that make up the ecosystem, are changeable. Many of today’s remnant/ predominantly natural ecosystems did not survive the last ice age intact – they are novel combinations of species that have come together in the last 10k years.
262 Changes in ecosystems caused by human intervention usually considered as degradation. But ‘ecosynthesis’ – the evolution of new ecosystems of native and exotic species in response to novel conditions – can have beneficial effects in moderating and repairing the environmental impact of human expansion, as well as providing new resources as plants and animals naturalise.
265 Knowing that ecosystems can evolve at remarkably fast rates in response to human and other influences will enable permaculture designers to introduce agricultural and other land use systems modelled on natural systems, by making a direct and conscious application of processes observed in nature. We need to recognise ourselves and our actions as part of nature, and avoid generalised judgements about our actions being good or bad.
267 Will biotechnology industries continue to attract massive investment capital once the high cost of energy becomes entrenched? Its ability to create lifeforms that are powerful without the support of a high energy economy is dubious anyway. Better to allow organisms to develop in response to real factors in the environment, rather than the cocoon of human illusions created in the laboratory or boardroom.
We are unable to stop the accumulation of risk of catastrophic damage resulting from nuclear radiation, the greenhouse effect, or genetic engineering. These out of control forces have replaced in the human psyche some of the high order large scale forces of nature (and/or the Gods) that previously precipitated catastrophic change as well as bestowing gifts of abundance.
The balance of quality of change will be important in a sustainable future. In industrial culture there has been a bias towards episodic change – crises and conflicts with great man as the leading actors. This ignores the less dramatic cyclical nature of ordinary life. Permaculture emphasises working with the rhythmic cycles of nature rather than excessive reliance on episodic intervention that knocks the system into some hopefully preferable state – but can lead to a spiral of degradation.
268 Masculine ways of action vs feminine culture – progressive rebalancing will be needed.
269 Geological timeframe context to the last 10k years – a fragile interglacial paradise.
270 We need to break out of the delusion of apparently linear acceleration of human material and numerical progress to a world view in which everything is contained by cycles, waves and pulses that flow between poles of great stability and intense change, all nested one within another.
271 Life for our children and grandchildren and their descendants is likely to be subject to uncertainty and rapid change. They must be prepared for this by acquiring a living appreciation of the enduring rhythms of nature, the value of long term thinking, persistent ethical behaviour, and the importance of the simple, ordinary (even mundane) aspects of life.