Archaeobotany

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As a mixed area of archeology and botany, archaeobotany tries to reconstruct the vegetation and agricultural history with the help of finds of plant origin. In addition to the macro residues (fruits, seeds, wood residues), micro residues (pollen, spores) also provide information on the vegetation of past times and allow conclusions to be drawn about the eating habits, cultivation methods, settlement history and climate of that time. Together with archeozoology , they form archeobiology .

The Palaeoethnobotany , not to be confused with the Paläobotanik in paleontology, deals as a mixed of ethnobotany with the Paleetnology , and places special emphasis on relationships between vegetation and settlement and the propagation of plants by humans ( Hemerochorie ).

Plant remains

  • Micro residues : pollen (grains), spores
  • Macro residues: Fruits and seeds, wood residues (including charcoal), moss, bast, fibers, in rare cases leaf residues, resin.

Conservation forms and sites

  • subfossil (organic material, partly chemically modified)
    • dry: deserts, caves, tombs, half-timbered houses
    • frozen: ice (glacier), permafrost soils
    • moist: water / groundwater; Moors, lakes, floodplains, ditches, wells, latrines
    • preserved by salts: mines, lying next to metal parts (coins, arrowheads)
    • Preserved by urine: rat heap
  • fossil (inorganic material, the appearance of which has been influenced by organic material)
    • Charred: Fireplaces, cremation and sacrificial sites, buildings destroyed by fires
    • mineralized: in latrines
    • Imprints: clay, pottery
  • fossil or sub-fossil in various products such as baked goods, leftover drinks, wooden tools, knitting

See also: Conservation conditions for organic material

Field and laboratory methods

Froth flotation of an archaeological soil sample

Macro remains can be found in archaeological excavations either through chance finds or through targeted taking of soil samples from wet or dry soils. The organic components are separated from the mineral (soil) material by sieving, sludging or flotation . Then the organic parts are examined under a stereo microscope (binocular) and the identifiable plant remains are read out. Then the finds are morphologically and anatomically determined and recorded quantitatively. The determination is made using a reference collection as well as descriptions, drawings and photos from other publications. There are very few limited identification keys for botanical macro residues.

Micro residues are obtained by taking soil samples (mostly drill cores), often from moors or lakes. Pollen grains and spores are extracted from these drill cores. The outer walls of the pollen grains and spores consist of extremely resistant sporopollenin , so that they are retained even in very strong acids and alkalis. The samples from the drill cores are treated with hydrochloric acid and hydrofluoric acid, among other things, in order to completely dissolve the mineral material. To neutralize humic acids, the samples are boiled in potassium hydroxide solution. In order to remove organic residues and to stain the pollen grains and spores for microscopic examination, the samples are acetylated. Alternatively, the mineral particles can also be separated from the pollen by gravity separation. The pollen enriched in the samples by this treatment is then placed on a microscope slide in a random sample. This random sample is examined for any pollen grains and spores obtained under a transmitted light microscope. These are determined using various identification keys and evaluated quantitatively.

Methods of dating the finds

  • Absolute dating:
  • Relative dating:
    • Palynology : pollen stratigraphic correlation
    • Tephrochronology : Determination of the deposits of volcanic ash (tephren)
    • Magnetostratigraphy : Determination of the traces of the earth's magnetic field reversal in the rock
    • Archeology : Correlation by comparison with other finds, e.g. B. Pottery

Problems interpreting the finds

When interpreting the results (e.g. determining the relative abundance of certain plants) one has to consider several factors:

  • Conservation selection - different plant remains survive for different lengths of time
  • Certain plants have different numbers of seeds or fruits per individual (e.g. fig compared to peach)
  • Different pollen production of self-pollinating and wind-flowering plants
  • human influences

Review the results

  • Comparison with other archaeological results
  • Carry out experiments on cultivation methods, combustion processes, etc.

literature

Web links