Subsistence Systems: Food Producing Systems

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Describes the three food producing systems: horticulture, intensive cultivation, and pastoralism. Discusses briefly the implications of all five systems on cultural materialism.

Transcript of Subsistence Systems: Food Producing Systems

  • 1. Subsistence Systems Food Producing Societies

2. Food Producing Societies: An Overview

  • Food producersare those peoples who domesticate plants or animals or both.
  • They work much harder than simple foragers, though not necessarily more so than complex foragers
  • Agriculturalists have to prepare the soil, plant their seeds or cuttings, weed the field, remove the pests, and finally harvest and process the crops.
  • Herders have to control or confine the animals, assist the birth of the young, feed the animals, milk them (and some draw their blood for consumption), shear the coats of some species, and slaughter them for meat and hides.
  • That means we have to explain what compels the producers to do so much more work than the simple foragers.

3. Food-Producing Societies: Their Beginnings and Consequences

  • First indications of domestication came in theNeolithic at about 10,000 BP I n the Fertile Crescent, including Israel, Lebanon, Syria, southern Turkey, and western Iran in theNear East (map, upper left)
  • Characteristics of the Neolithic included the domestication of plants (such as emmer wheat, lower photo) and animals, such as cattle, pigs, sheep, and goats.
  • Advantages consisted of human control over food production, greater quantities of food compared with simple foragers, and settled communities

4. Food-Producing Societies: Secondary Consequences

  • The greater productivity of agriculture allowed for greater time in various non-agricultural crafts and labor
  • Economic specialization meant that a system of exchange would arise: administered trade and markets
  • Population increase meant that complex social control mechanisms would arise.
  • This would mean that society would become more complex, more stratified, and more centralized.

5. Typology of Food-Producing Systems

  • However, not all the food producing systems are the same. We look at three different types
  • Horticulture:the cultivation of crops using hand tools such as the hoe and digging stick.
  • Pastoralism:The herding of animals, such as goats, sheep, cattle, horses, even camels.
  • Intensive Cultivation or Agriculture:Cultivation involving higher technology, such as irrigation or animal (or tractor) driven plows, resulting in higher yields.
  • Some of these systems exist at the exclusion of others, but most combined the main subsistence strategy with others.
  • Example:The Aztecs used both irrigation and hoe cultivation.

6. Horticulture

  • Horticulturemay be defined as the cultivation of crops carried out with hand tools, such as digging sticks, hoes, machetes and a specialized tool in Mesoamerica as the coa.
  • Neither plows nor irrigation systems are used.
  • A field usually lies unused for a period of time to enable it to regain its fertility
  • The best known type of cultivation involves use ofslash-and-burnorswiddencultivation, and we will focus on this system.

7. Basics of Slash-and-Burn Cultivation

  • In slash and burn, a site is cleared of brush and trees; trees are felled, and brush is cut and stacked
  • This phase is completed usually at the beginning of the dry season
  • Once dried, usually at the end of the dry season, the brush and trees are set afire (top photo).
  • Planting begins at the beginning of the rainy season and usually different species of crops are planted together, orinterplanted.
  • Once soil is exhausted,site is abandoned (bottom photo) and a new site is cleared

8. Slash-and-Burn Cultivation: Adaptive Significance

  • Most slash-and-burn cultivation is practiced in the tropics.
  • Tropical climate is extremely hard on soils because of the intense heat from the sun, the heavy rainfall, and the chemical reaction called laterization in soils containing minerals caused by the heat and moisture.
  • Slash-and-burn is best adapted to this climate--which the following slides will show.

9. Constants of Tropical Rainforest: Intense Heat

  • Plant and animal matter decompose to formhumusortopsoil,the organic accumulation of soil in which all plants grow.
  • Humus formation virtually stops if topsoil reaches 77 degrees Fahrenheit.
  • At that temperature, decomposition of humus exceeds formation, while humic materials break down to gases: ammonia, nitrogen, and carbon dioxide.
  • These gases escape into the atmosphere, leaving little nitrogen left for the topsoil.

10. Constants of Tropical Rainforest: Rainfall

  • Rainfall acts on the soil in two ways
  • Erosion, whereby rainfall carries away soil particles. The particles themselves scour the surface, and the abrasion carries off even more soil
  • Leaching is the other process: the warm water dissolves water-soluble nutrients, whereby the nutrients seep into subsoil away from the roots of the plants.

11. Constants of Tropical Rainforest: Laterization

  • Laterite is a compound comprisingthe oxides of minerals, such as the iron oxide at the top layer of this soil(photo)
  • The combined heat of the sun and moisture of the rain create these oxides
  • Once started, the process is irreversible.
  • The process removes phosphorus, an essential nutrient, and the laterite cannot absorb other nutrients

12. A Long-Term Constant: Age of Soil

  • In the Amazonian region of South America, this process has been going for centuries.
  • The soil composition is mostly clay and sand, neither of which is high in content or calcium
  • Because calcium if limited, plant and animal life in Amazonia is limited in protein content
  • Seed reproduction required high levels of protein, so that most plants in Amazonia reproduce by daughter shoots sprouting form parent plant, calledvegetative
  • Animals that feed on these plants are generally small, such as this woolly monkey, and live in isolation rather than groups.
  • Gregarious (herding) animals are rare

13. Adaptation of Tropical Rainforests

  • Natural selection pressures have favored vegetation protective of the soil.
  • The first feature is that trees develop a protective canopy of thick leaves aided by epiphytic plants, plants that receive their nutrients from rainfall and the atmosphere.
  • The second feature is the high rate of growth of the trees, which involve a rapid utilization of the nutrients in the soil.
  • The third feature is the juxtaposition of different types of trees, which have different nutrient requirements, in the same location so that all nutrients are utilized.

14. Protective Canopy

  • Mature forests contain trees with thick foliage at their tops, made up of their leaves and supplemented by epiphytic plants.
  • They have several protective functions:
  • First, they provide protective shade from the sun, cooling the soil below 77 o F and so allowing humus to accumulate.
  • Second, they screen the rain so that it falls in a fine spray.
  • Third, the epiphytic plants absorb some of the rainfall, so the amount reaching the forest floor is 70% of the total rainfall .

15. 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

16. Species Juxtaposition

  • Different tree species have different nutrient requirements, and so grow in the location
  • Some trees require more phosphorus than others, while other trees other require more potassium.
  • Nutrients left by one tree is taken by others
  • In the meantime, trees of the same species are dispersed, so the dispersal inhibits the spread ofpestsand diseases that infect that species .

17. What Would Happened if Trees in the Tropics Were Cleared?

  • In the absence of trees, the soil would soon be compacted and become infertile.
  • Humus would not form, especially in the absence of litter from tree leaves and animal droppings.
  • Erosion via runoff would increase, and the soil would be leached to infertility.
  • All the topsoil would be converted to laterite
  • Overall, soil fertility would decrease or disappear entirely.

18. Slash-and-Burn Cultivation Techniques: The Munduruc

  • This section explains how the Munduruc practice slash and burn cultivation.
  • First, they select a sloping, well-drained area, so that excessive water does not destroy the crops
  • They then start clearing the brush and small trees at the beginning of the dry season.
  • They fell the trees by cutting through most of the trees to be cleared
  • Then fell a tree that kn