Subsistence Systems

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Comparative Food Colllection and Production Systems

Transcript of Subsistence Systems

  • 1. Subsistence Systems Making a Living Cross-Culturally

2. What are Subsistence Systems?

  • Ways of making a living--directly
  • Types of subsistence Systems
  • Foraging/Hunting and Gathering
  • Horticulture
  • Intensive Cultivation or Agriculture
  • Pastoralism
  • Equestrian Hunting

3. Why Study Subsistence Systems?

  • Kingdom:Animalia:
  • We cannot produce food by photosynthesis--no chlorophyll
  • Therefore, we ultimately rely on plants
  • We are how we produce
  • Foragers are organized around the hunting and the gathering
  • So are horticulturists in horticulture
  • So are all the others

4. Subsistence Systems and Adaptation

  • Culture is largely adaptive
  • Main locus of adaptation: subsistence
  • As subsistence systems become more complex
  • Societies become more complex
  • Therefore societies evolve from the simple to the complex

5. Overview

  • Subsistence systems
  • Principles of cultural materialism
  • Cultural Evolution
  • Cultural Ecology
  • History of evolutionary thought

6. Types of Subsistence Systems

  • Foraging or Hunting Gathering : Hunting animals, gathering plants
  • Horticulture:Cultivation with digging stick, hoe, or other hand tool(s)
  • Intensive Cultivation:Cultivation with high-yield technology: irrigation, plow
  • Pastoralism:Herding large animals
  • Equestrian Hunting:Hunting using draft animals (horse, reindeer)

7. Foraging: Main Features

  • Food is where you find it
  • Direct dependence on naturally available plants and animals
  • Plant foods (like these mongongo nuts gathered by !Kung women)
  • Form 80% of the diet among most foragers
  • Near total reliance on hunting is rare (as among the seal-hunting Inuit here)
  • Fluctuation of food sources by place, season, and year
  • Means of meat storage rare or nonexistent
  • Foragers do have wide variety of food

8. Foraging: Carrying Capacity

  • Population limited by
  • Carrying capacity: population resources can support
  • Density of social relations
  • Liebigs Law of the Minimum
  • Populations may not increase
  • Beyond the minimum amount of critical resources
  • That an environment yields

9. Liebigs Law of the Minimum Illustrated

  • The lowest stave of a barrel limits its capacity
  • Crops can yield only as much
  • As the amount of a critical nutrient
  • Applies to carrying capacity limits

10. Foraging: Sharing and Property

  • Sharing ethic: shared according to rules
  • Netsilik Inuit: Partnerships by seal anatomy
  • !Kung: Hunters and owner of arrow own the game
  • Owner is only stewardship
  • Game is shared by definite obligations
  • Property: Communalism

11. Foraging: Other Derived Characteristics

  • Egalitarianism
  • No incentive to hoard
  • Social class differences minimal
  • Work time
  • Average: 15-20 hours/week
  • Nonintensive labor with other activities
  • Domestic mode of production: work done until needs are met

12. Foragers: Contemporary Ancestors?

  • Some societies may reflect early foragers
  • Qualifications
  • Foragers could bedeculturated
  • !Kung may have been herdsman once
  • Reduced to foraging by Bantu expansion
  • Foragers occupy margins of earth
  • Desert (SW Africa, Australia, Nevada basin)
  • Extremely cold regions (Arctic regions)

13. Food-Producing Societies

  • First indications: Neolithic ca 10,000 BP
  • In the Fertile Crescent, Near East
  • Characteristics
  • Domestication of Plants (emmer wheat), animals, or both
  • Human control over food production
  • Quantities of food greater than foragers
  • Settled communities (except herders)
  • Increases in population
  • Complex social structures.

14. Horticulture

  • Definition
  • Cultivation of crops
  • Carried out with hand tools
  • Such as digging sticks or hoes
  • Neither plows or irrigation systems are used
  • Best known type of cultivation involves use ofslash-and-burnorswiddencultivation

15. Basics of Slash-and-Burn Cultivation

  • A site is cleared of brush and trees
  • Trees are felled, brush stacked
  • Once dried, the brush and trees are set afire (top photo).
  • Planting begins
  • Usually, crops are interplanted
  • Once soil is exhausted,site is abandoned (bottom photo)
  • Cultivators clear a new site

16. Slash-and-Burn Cultivation: Adaptive Significance

  • Most slash-and-burn cultivation is practiced in the tropics
  • Tropical climate is extremely hard on soils
  • Intense heat
  • Heavy rainfall
  • Chemical reaction from heat and rain
  • Slash-and-burn is best adapted to this climate--which the following will show

17. Constants of Tropical Rainforest: Intense Heat

  • Plant and animal matter decompose to formhumusortopsoil
  • Humus formatio virtually stops if soil reaches 77 degrees Fahrenheit
  • Decomposition of humus exceed formation
  • Humic materials break down to gases: ammonia, nitrogen, carbon dioxide
  • Gases escape into the atmosphere

18. Constants of Tropical Rainforest: Rainfall

  • Rainfall acts on the soil in two ways
  • Erosion:
  • Rainfall carries away soil particles
  • Particles themselves scour surface]
  • Abrasion carries off even more soil
  • Leaching
  • Warm water dissolves water-soluble nutrients
  • Nutrients seep into subsoil

19. Constants of Tropical Rainforest: Laterization

  • Laterite: the oxides of minerals
  • Such as iron oxide at top layer (photo)
  • Combined heat and moisture creates oxides
  • Process is irreversible
  • Removes phosphorus, an essential nutrient
  • Cannot absorb other nutrients

20. A Long-Term Constant: Age of Soil

  • This process has been going for centuries
  • Soil is mostly clay and sand
  • Plant and animal life is limited in protein
  • Most plants reproduce by vegetative means
  • Seeds involve large amounts of protein
  • Animals are small
  • Gregarious (herding) animals are rare

21. Adaptation of Tropical Rainforests

  • Protective canopy of leaves and epiphytic plants
  • Rate of growth
  • Juxtaposition of different types of trees

22. Protective Canopy

  • Mature forests contain trees with thick foliage at their tops
  • Thick network of leafy branches
  • Epiphytic plants that derive nutrients from rain and air
  • Protective functions
  • Provide protective shade from sun, allowing humus to accumulate
  • Lessens action and amount of rainfall

23. Rate of Growth

  • Rate of growth is spectacular
  • Enables rapid use of nutrients before they disappear through erosion or leaching
  • Litter fall of animal remains and dead vegetation
  • Is four times of woodland in New York state
  • Rainfall also captures nutrients from air
  • 75% of potassium in soil, 40% of magnesium, and 25% of phosphorus come from rainwater

24. Species Juxtaposition

  • Different tree species have different nutrient requirements
  • Some require more phosphorus than others
  • Other require more potassium
  • Nutrient left by one tree is taken by others
  • Dispersal of same species is protection against pestsand diseases

25. Clean clearing would

  • Compact the soil due to heavy rainfall
  • Erosion via runoff would increase
  • Minimize or eliminate formation of humus
  • Leach the soil
  • Convert the soil into laterite
  • Overall: reduce its fertility

26. Slash-and-Burn Cultivation Technique

  • Review of distinctive features
  • Cutting and burni