Ruralisation integrating settlements and agriculture to provide sustainability

Ruralisation – integrating settlements and agriculture to provide sustainability Folke Günther Dept. of Systems Ecology, Stockholm University E-mail: Folke. Gunther@humecol. lu. se URL: http: //etnhum. etn. lu. se/~fg/index. htm Folke. Gunther@humecol. lu. se

Is energy cheap? Availabilty for gasoline energy at gas station (working time for one k. Wh) Energy availability today: About ten times more than 1920 Folke. Gunther@humecol. lu. se 2

Adaptation to cheap energy: Case 1: agriculture Improved wheat Wild wheat Necessary functions: High yield (seed production with residual energy) The farmer takes care of: Low yield (seed production with residual energy) Pest defence Competition with neighbours Seed distribution Pest defence Seed distribution Competition with neighbours Planting Folke. Gunther@humecol. lu. se Planting by the use of fossil fuels 3

Adaptation to cheap energy, Case 2: settlements Assume: Four persons living in a house Food management: The house: The car (Energy efficiency less than (assuming 10: 1) 15 000 km/yr) Saving potential: about 32 000 k. Wh/yr (associated with vulnerability to high energy prices) Conventional house (according to ’Byggnorm 80’) Heavy car (10 -12 l/100 km) Super-isolated house Light car (5 -7 l/100 km) Assumed local handling, 4000 k. Wh Saving potential: about 8 000 k. Wh/yr Necessary for about respiration, 4000 k. Wh 6 000 k. Wh/yr Folke. Gunther@humecol. lu. se 4

Will energy prices continue to be low? The Hubbert Curve Maximum finding rate Found each 5 year period Ultimately found Used Folke. Gunther@humecol. lu. se 5

Different utilisation modes of remaining resources Rule: You can not use what is not found ∫’found’(x) dx ∫ A: The Bush mode ≥ ’used’(x)dx B: Unprobable mode C: Probable mode Folke. Gunther@humecol. lu. se 6

Will energy prices continue to be low? The Big rollover Will this be our gloomy future? Folke. Gunther@humecol. lu. se 7

Why phosphorus? The constituents of an animal (or vegetable) body: H With O gaseous phases C — can be N transported S by the air S P Na K Ca 10 times more common in the Without body than in the Earth crust gaseous phases More common — be in must the Earth transported crust than in as solids or the body … 64 liquids … 64 Folke. Gunther@humecol. lu. se 8

The HEAP trap Hampered Effluent Accumulation Process Folke. Gunther@humecol. lu. se 9

The HEAP trap H ampered E ffluent A ccumulation P rocess J Q k. Q (stored amount) J Q Folke. Gunther@humecol. lu. se J=k. Q (leakage) 10

Linear flows STORAGE EXHAUSTION: P extraction horizon: about 130 years (at current energy price) Increasing energy use per unit Increasing energy price Actual extraction horizon: Unknown Import of nutrients compensates export of produce HEAP: Leakage equals import Folke. Gunther@humecol. lu. se HEAP: Leakage equals import 11

Linear flows HEAP Folke. Gunther@humecol. lu. se 12

A G R I C U L T U R E same The amount, 20% S need E to be imported T T L E M E N T ’Balanced agriculture’: -- manure is used for fodder production About 80% of the nutrients are The balanced agriculture 1% circulated — settlement The leakage from a normal agriculture represents about the turnover of About 20% is exported This represent the nutrient turnover of about 6 persons Folke. Gunther@humecol. lu. se 13

Conclusion 1 About 6 persons are in nutrient balance with 1 hectare of balanced agriculture This means that about 0, 2 hectares of such agriculture can support one individual without HEAP effects Provided that the nutrient containing residues are returned to the agriculture Folke. Gunther@humecol. lu. se 14

Rules for sustainability 1. You can not be dependent on storages n Neither of energy Solution: Energy flows n Nor of nutrients Solution: Recycling 2. Corollary: Food should be produced as close as possible to the consumer in You must have a supportive function to diminish food system energy on your order support system needs and maximise nutrient recycling Solution: capacity Improve (not just maintain) the health of your ecosystem Folke. Gunther@humecol. lu. se 15

The eco-unit Area: 50 ha for 200 inhabitants Diversified agriculture Functional size, pop. about 200 Plant nutriens in food are returned to agriculture Orchards Private gardens Biological greywater treatment plant (wetpark) Clean water is returned to the households Folke. Gunther@humecol. lu. se Providing most of the human food and all of the animal fodder Open ditches Nutrient reclaim Landscape diversity Predator habitat Lee – planting Biomass production 16

The ruralisation scenario – start point In this scenario, the following things are supposed: #A is imagination made by a have scientist 4. scenario 1. 2. 3. The Furthermore, They Instead city have of is building inhabited thean they same understand new knowledge by decisionmakers housesthat on of limiting the places city who resources, is not where static, thethe At point, the centre of the municipality old start capacity ecology but ones dynamic. and to were make the Old torn rules far-sighted houses down, for are long-term they and torne decide strategic down survival to build and decisions as new eco-units you. are built. in # The rules are: (The average life-time a house is supposed to be 60 years, which the of thefortown. hasperiphery a population of 33 000 gives the cityimagine a rate of change of 1, 6%) You the most ridiculous The can periphery is inhabited by 3 000 things But you have to render a statement of the effects Folke. Gunther@humecol. lu. se 17

Ruralisation – after 12 years With the given rate of change, the centre of the municipality has a population of 24 000 The periphery is inhabited by 12 000 Local parks replacing the old houses Folke. Gunther@humecol. lu. se Groups of four Eco-units Each group is inhabited by 800 people 18

Ruralisation – after 25 years At this stage, the centre of the municipality has a population of 12 000 The periphery is inhabited by 24 000 Reversed ditching: 5 600 persons Folke. Gunther@humecol. lu. se Underground streams are brought up to the surface 19

Ruralisation – after 50 years At the end of the ruralisation process, the centre of the municipality has a population of 3 000 The periphery is inhabited by 36 000 Minimal dependency of fuel Many characteristics Area with integrated of the Noarea HEAP-trap (P/R-ratio, nutrient storages due retention agriculture capacity, – mutualism, settlements. Nutrients are biodiversity) circulated are to: § Localised food-system closing. Population to those ofdensity matureclosing ecosystems. § Use of wind, solar-power to 500/km 2 and biomass … and the decision-makers are still there. . Folke. Gunther@humecol. lu. se 20

The economy of ruralisation In this calculation, it is not possible to account for changes of the ’Rollover’ type. Therefore, continuous, steady changes of energy prices are assumed Very small 5% difference: (In this case: annual increase in price for industrial Increased human energy, and 2% for renewable energy sources) transport equals diminished food transport an h Unc ty ci d e g 2, 000, 000 SEK difference Ruralisation Folke. Gunther@humecol. lu. se 21

Conclusions There is an immediate need for finding strategies to avoid dependence on storages of: Energy Nutrients For sustainability, these strategies must also include a supportive behaviour towards the supporting ecosystems Regarding these restrictions, the urban structure common today is unsustainable Folke. Gunther@humecol. lu. se 22

Conclusions To avoid dependence on storages of: Energy — use flows or funds Nutrients — recycle This will impose restrictions on distance Folke. Gunther@humecol. lu. se 23

Conclusions To establish a supportive behaviour towards the supporting ecosystems: Adapt to behaviours typical to mature ecosystems Folke. Gunther@humecol. lu. se 24

Conclusions All these strategies can be established in the border of the urban structures common today Folke. Gunther@humecol. lu. se 25

Conclusions By advanced undulation of the borders, leading to the integration of the city with its hinterland, some obstacles to sustainability may be overcome Folke. Gunther@humecol. lu. se 26

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