hunter-gatherer societies and traditional agriculture

Energy in human-environment interactions WS 2007

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Hunter-Gatherer societies and traditional agriculture

Maria Lackner 0025209

Tamara Neubauer 0201045

Mirjam Weber 0052101


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Structure of the presentation

1) How to measure energy in human-environment interactions – (general considerations)

2) Energy flows in Hunter-Gatherer and early agricultural societies

3) Energy flows of traditional agriculture in Pura (India)


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How to measure energy in human-environment interactions

(general considerations)


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general questions:

• What problems do we encounter when assessing energy in human-environment interactions?

• How do we estimate human energy?

• How do we assess the energetics of human labor?

• How do we measure energy efficiency?


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Problem No. 1Focus on „commercial“ energy in statistics

Example India:

energy use/capita = U.N. coal equivalent of 150 to 190 kg

but: total energy use from all sources = 490 kg


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Problem No. 2Estimation of Human Energy

Method

energy per worker (kcal/hour)gross input (expenditure)

Pimentel et al. 580

Makhjani and Poole 870

Passmore and Durnin 250


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Problem No. 2Estimation of Human Energy Pimentel et al.:

energy utilized in farm labor = total food energy input of a fulltime farm worker (40 hours a week)

Makhijani & Poole:

energy in the food intake of all persons in a farming village = gross energy input for human labor

Passmore & Durnin:metabolic energy used in different work activities (oxygen consumed, carbondioxide exhaled)

580 kcal/hour

870 kcal/ hour

250 kcal/ hour


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Problem No. 3Estimation of Animal Energy

Method

energy input per bullockkcal/hour/bullock

1a) 12.1 x 10³ kcal/hour of work

1b) 10.9 x 10³ kcal/hour of work

2) 5.3 x 10³ kcal/hour of work

3) 2.3 x 10³ kcal/hour of work


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1a) net energy input (feed energy – energy in dung) – energy in milk and other products

1b) consideration of the herd‘s milk production

12.1 x 10³ kcal/h

10.9 x 10³ kcal/h


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2) [energy/year consumed by the bullock (feed) – energy in dung] / hours worked = gross energy expenditure per working hour

3) weekly energy expenditure of a bullock is ca. 43% of ist total food energy intake for the week

5.3 x 10³ kcal/h

2.3 x 10³ kcal/h


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Problem No. 4Energy efficiency – which parameters?

e.g. maximization of economic profit vs. minimization of risk

e.g. maximization of crop yield vs. minimization of ecosystem degradation


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Problem No. 5power generation

total energy requirements = sum of 2 flows of energy

1. flow used directly to generate power

2. flow calculated as the energy spent in the construction and maintenance of the structure delivering power


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Problem No.6power level is often not considered

work = carrying 400 kg of sand upstairs 5 m of height

5 m400 kg


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Problem No.6power level is often not considered

work = carrying 400 kg of sand upstairs 5 m of height

3 possibilities:

a) 5 trips carrying 80 kg

b) 20 trips carrying 20 kg

c) 100 trips carrying 4 kg


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Problem No.7difficulty in quantifying a defined work done

Power system Labor requirement

(h)

Level of power (W)

Power generation

cost (EI/AP)h

Acquirement index

Manpower 400 75 100 1.00

Oxen pair 65 895 25 0.51

6-HP tractor 25 4476 8 0.25

50-HP tractor 4 37300 8 0.20


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Problem No.7difficulty in quantifying a defined work done

Applied power (MJ) Gross energy requirements (MJ)

Manpower 107 10700

Oxen pair 209 5200

6-HP tractor 403 3100

50-HP tractor 537 4100


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factors related to the level of energy consumption per capita for rural/poor societies based on manpower:

1. body size

2. quality of the diet

3. exosomatic energy flow (energy flows converted to useful work outside the human body)


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Literature:

• Roger Revelle – Energy Use in Rural India

• Giampietro & Pimentel – Energy efficiency: assessing the interaction between humans and their environment

• Giampietro & Pimentel – Assessment of the energetics of human labor


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Energy flows in Hunter-Gatherer and early agricultural societies

•Energy flows in gerneral•The Kung! Bushmen – hunter and gatherers•The Tsembaga – early agriculture society

•The energetic benefits of domestication


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Energy flows in Hunter-Gatherer societies (Pimentel 1996)

Wherefore energy? Obtaining food + collecting firewood

Basal metabolism: 1080 kcal + …

Examples for Energy requirements for various activities In kcal/h

Sitting, standing relaxed 20

Walking 130-240

Climbing 400-900

Running very quickly 1240

Walking loaded (10kg) 400


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Wherefrom energy? Wild plants and animals (wood for fire ?)

Total annual production of plant biomass in a temperate region averages about 2400kg per ha. Under favourable conditions this quantity might support an animal and microbe biomass of about 200kg per ha.

The proportion of the total animal and microorganisms biomass of 200 kg

42%

25%

20%

2%

1%

10%

Microorganisms

Earthw orms

Arthropods

Mammals

Birds

Other animals


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How much land do hunter-gatherers need?

Pimentel: 40 hectare (ideal ecosystem)Modern-day hunter-gatherers need much more (150-250ha)

In the northwestern Canadian region about 14.000 ha per personIn subarctic lands up to 50.000 ha per person !Kung Bushmen about 1000ha.

Comparison: Austria is 84’000 km2 = 8.400.000 ha

200.00040.000

8.400


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Energy flows in Hunter-Gatherer societies - The !Kung Bushmen

• Population density: 1 person per 1040 ha• Most of the daily calorie intake of the !Kung

Bushmen (56%) are mongongo nuts.• A critical decision for the bushmen is where to

locate their camps. Food and water must be near enough. They occupy a camp for a period of weeks and eat their way out of it.

• Energy Output/Input ratio falls with distance(19km: 2 day trip)

Lee, 1969


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Energy flows in Hunter-Gatherer societies - The !Kung Bushmen

hours Kcal

Travel to location of nuts 1,2 270

Collecting nuts 3 675

Return trip (+12,5kg nuts) 1,2 462

Sleep 10,5 473

Other activities 8 800

INPUT 24 2.680

OUTPUT (shelled nuts 1,75kg) 10.500

Output/Input ratio 4:1

Output/Input analysis of !Kung bushmen gathering mongongo nuts at a distance of 4,8 km from their camp


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• Population density: 1 person per 4 hectare• Early agricultural society in New Guinea• Tropical mountainous ecosystem, rainy• Swidden-type agricultural system

(Brandrodungsfeldbau)

• Food of plant origin (taro, sweet potatoe, fruit, leaves, bananas, yams) 99%

• Some pigs

Energy flows in early agricultural societies – The Tsembaga

Rappaport, 1968

Early agriculture:no fossil fuels, no animal power


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Energy flows in early agricultural societies – The Tsembaga

Hours/ha Kcal/ha

Clearing underbush 175 70.000

Fencing garden 84 42.000

Weeding and burning 78 23.400

Planting and all weeding 742 222.600

Harvesting 277 83.100

Axe, machete - 16860

INPUTS 1.860 739.160

OUTPUT (Crop yield) 11.384.462

OUTPUT/INPUT RATIO 15:1

Output/Input analysis of New Guinea swidden agriculture for 1 ha of mixed crops

Energetical input of wood and vegetation for fire ?


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Livestock in early agricultural societies – The Tsembaga

Output/Input ratio of pigs 1:2 Why?

• Stock (Pimentel)• Distribution of surplus wealth (Rappaport)

Kaiko ritual (pigs for the ancestors < carrying capacity)

Energetic benefits of domestication

• „Non convertable“ grasses → usable energy • Animal power → energy source (beast of burden)• Need of protein →Herding more energy efficient as hunting


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Energy flows in Hunter-Gatherer societies

Food, Energy and Society, David and Maria Pimentel, 1996.

• Chapter 6: Hunter – Gatherers and early agriculture.

• Chapter 7: Early livestock systems and animal power.

AgricultureAn example from India

Pura 1977

www.export.gov.il

www.faorap-apcar.org


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Pura 1977

• South India

• Karnataka State

• - 56 households

• - 357 people

• - 671 meters above sealevel

• - Annual rainfall of 127 centimeters


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Overview

Energy consumption patterns of Pura

Ranking of energy sources

Energy- Activity Matrix

Ranking of activities requiring energy

End Uses of Human Energy

Health Hazards for the people of Pura


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Energy Consumption Patterns

Energy used for:

- agricultural operations

- domestic activities

- lighting

- Industry

www.news.bbc.co.uk

www.images.wir.orgwww.images.wir.org

Agriculture

An Example from India


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Ranking of energy sources per year:

1) Fuelwood (89%)2) Human energy (7%)3) Kerosene (2%)4) Bullock energy (1%)5) Electricity (1%)

www.rcfa.cfan.org

www.glamro.gov.uk

Agriculture



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Energy- Source Activity Matrix

Agriculture



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Ranking of activities requiring energy:

1) Domestic activities (91%)

2) Industry (4%)

3) Agriculture (3%)

4) Lighting (2%)

Agriculture



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Women Children Men

Gathering fuelwood

42% 25% 33%

Fetching water

80% 14% 6%

Grazing

livestock15% 33% 52%

www.rediff.com


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The use of low level energy sources in Pura causes:

- high human time input

- high labor effort

- health hazardswww.fao.org

Agriculture



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Why health hazards?

- Dependence on biomass cooking fuels

= fuelwood, dung cakes, crop wastes,...

= high toxic emissions like carbon monoxide, suspended particulates, hydrocarbon!

Agriculture



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Health Effects

Production: Skin infections, enteric infections,...

Collection: Trauma, allergic reactions, bites from reptiles,...

Combustion: respiratory irritation, burns, chronic bronchitis,...

Agriculture



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A Greater Health Impact for women and girls (1)

- daily subsistance chores lead to a higher calorie expenditure/day (not compensated by food intake)

- Domestic tasks more often done by women or girls are perennial and not seasonal

- Depletion by repeated births

Agriculture



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A Greater Health Impact for women and girls (2)

- especially traditional rice cultivation methods cause complications for pregnant women

- Increase of stillbirths, premature births and neonatal mortality while rice during rice planting months

- Lack of adequate water = increase of genito- urinary and reproductive tract infections which stay untreated für years

Agriculture



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Facit: low levels of energy services are a serious problem!

- People of Pura depend on human energy and primitive technologies for their daily survival

Agriculture



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Literature:

• Srilatha Batliwala - Energy as an obstacle to improved living standards

• Roger Revelle - Energy Use in Rural India

Agriculture


hunter-gatherer societies and traditional agriculture

Documents

dung energy

energy efficiency

metabolic energy

commercial energy

energy usecapita

gross energy input

total energy use

gross energy expenditure