Pal(a)eoethnobotany or Archaeobotany, "is the study of remains of plants cultivated or used by man in ancient times, which have survived in archaeological contexts". Paleoethnobotany is the archaeological sub-field that studies plant remains from archaeological sites. Basing on the recovery and identification of plant remains and the ecological and cultural information available for modern plants, the major research themes are the use of wild plants, the origins of agriculture and domestication, and the co-evolution of human-plant interactions.
Plant macrofossils are preserved through four main modes of preservation at archaeological sites. First, plant remains, usually cereal grains, chaff, seeds and charcoal are largely reduced to elemental carbon (charred) when they are heated in a reducing atmosphere . These are referred to as 'charred' or 'carbonised' plant remains. This mode of preservation is biased towards plant remains that come into contact with fire, through cooking or fuel use, and those which are less fragile, such as cereal grains and nutshell . Second, plant remains deposited in permanently waterlogged anoxic conditions are preserved as the absence of oxygen prohibits microbial activity . This mode of preservation occurs in deep archaeological features such as wells, in urban settlements where organic refuse is rapidly deposited, and at settlements adjacent to lakes or rivers. A wide range of plant remains are usually preserved, including seeds, fruit stones, nutshells, leaves, straw and other vegetative material . Third, calcium-phosphate mineralisation of plant remains occurs usually in latrine pits and in middens, as plant remains are completely replaced by calcium-phosphate. In latrine pits, plant remains which have been consumed by humans are the most common items, such as seeds of flavourings, fruit pips and fruit stones . Finally, plant remains are preserved by desiccation in arid environments, where the absence of water limits decomposition. Delicate vegetative plant remains are preserved, such as onion skin and artichoke bracts, along side fruit stones, cereal chaff and seeds of wild plants .
Paleoethnobotanists use a variety of methods to recover and identify plant remains. One method used to recover macroremains (objects larger than 100 µm, but smaller than 10 cm) is to sieve excavated material manually in a water bath in order to allow the organic material to float to the surface. This method is known as flotation. The matrix (the soil from a suspected archaeological feature) is slowly added to agitated water. The soil, sand, and other heavy material, known as heavy fraction, will sink to the bottom. The less dense organic material such as charred seeds, wood and bone will tend to float to the surface. The material that floats to the top, called light fraction, is gathered with a sieve. The organic light fraction is then available for examination. Samples of the heavy fraction are also gathered for later analysis. Other types of flotation processes include machine-assisted flotation and froth flotation. Paleoethnobotany makes it is possible to collect data on past cultures through plant remains, which may offer insight on how agriculture changed over time. It may also provide evidence of trading systems, or knowledge of medicinal properties of plant materials. Paleoethnobotany can also be used to help understand the diet of a culture, and when used in collaboration with zooarchaeology it offers insight on what animals may have been present at the site.
Identification of macroremains is then usually carried out under a stereomicroscope, using morphological features such as shape and surface features in the case of seeds, or microanatomy in the case of wood or charcoal. Identification literature as well as a comparative collection of modern plant materials are crucial for reliable results. Depending on the type of material, and its condition, also other methods such as thin sections or SEM are applied.
Paleoethnobotanists also recover and analyze microremains (such as phytoliths and pollen), human and animal excrements (paleofeces, sometimes called coprolites), or plant impressions in ceramic sherds and clay (such as in daub).
Dendrochronology, the study of growth rings on trees relating to study of past environments, is another scientific discipline useful to paleoethnobotanical study.
Zooarchaeology, is also useful in collaboration with Paleoethnobotany, it is the study of animal remains at an archaeological site. Focusing on bones and other hard material remains.
Taphonomy, studying how recovered materials have decayed, and what sort of organisms are on the decaying material.
The work done in paleoethnobotany can be divided into field work, collections management, systematic description of species, and theories into the origins of human and plant interaction. Some examples of this analysis:
A paleoethnobotanist may find discrete concentrations of burned or dried remnants of seeds in an area of discolored soil (a possible hearth feature). If later analyses indicates that the remnants were of only mature wild seeds of a type of plant that grows locally, it could be inferred that the site was only visited seasonally. Such an inference could be supported by a lack of other features that would suggest that no permanent shelters were built at the site.
Alternatively, a paleoethnobotanist may find that a fire pit feature contains concentrated remnants of a wide variety of edible wild plants that mature throughout the year. An archaeologist may find features at the site that indicate some sort of semi-permanent dwellings (such as post holes and middens). The middens may have concentrations of animal remains, identified by a zooarchaeologist as those of wild game, with a variety of species-specific maturity levels. In that case, a more permanent settlement may be inferred, perhaps to the level of a village. Such an analysis of the archaeological features could suggest a society of hunter-gatherers who inhabited the site on a more-or-less year-round basis.
A paleoethnobotanist may also find concentrated remains of plants that typically are only grown through active cultivation (such as cereals, legumes, and oilseeds). At the same site, an archaeologist might identify features such as stone walls surrounding enclosures arrayed in a pattern, and deep, layered middens with concentrations of domesticated animal remains such as goats or pigs. An analysis of the site, set within the context of the archaeological features and animal and plant remains, would suggest a settled agrarian community.
- Current Paleoethnobotany Analytical Methods and Cultural Interpretations of Archaeological Plant Remains
- Märkle, T; Rösch, M. "Experiments on the effects of carbonization on some cultivated plant seeds". Vegetation History and Archaeobotany 17: 257-263. doi:10.1007/s00334-008-0165-7.
- Hillman, G (1981). Mercer, R, ed. Farming Practice in British Prehistory. Edinburgh: Edinburgh University Press. pp. 123–162.
- Kenward, H; Hall, A (2014). "Urban organic archaeology: an irreplacable palaeoecological archive at risk". World Archaeology 40 (4): 584–596. doi:10.1080/00438240802453286.
- Jacomet, S (2013). Menotti, F; O'Sullivan, A, eds. The Oxford Handbook of Wetland Archaeology. Oxford: Oxford University Press. pp. 497–514.
- Smith, D. "Defining an ‘indicator package’ to allow identification of ‘cess pits’ in the archaeological record". Journal of Archaeological Science 40: 526–543. doi:10.1016/j.jas.2012.06.014.
- Van der Veen, M (2007). "Formation processes of desiccated and carbonized plant remains e the identification of routine practice". Journal of Archaeological Science 34 (6): 968–990. doi:10.1016/j.jas.2006.09.007.
- Virginia S. Popper, and Christine A. Hastorf "Current Paleoethnobotany Analytical Methods and Cultural Interpretations of Archaeological Plant Remains," 1988, The University of Chicago Press. (page 2)
- Pearsall, Deborah M, Paleoethnobotany: A Handbook of Procedures, Second Edition, Academic Press, San Diego (2000), ISBN 0-12-548042-3.
- Christine A. Hastorf (Editor), Virginia S. Popper (Editor), Current Paleoethnobotany : Analytical Methods and Cultural Interpretations of Archaeological Plant Remains (Prehistoric Archeology and Ecology series), University of Chicago Press (January 15, 1989), ISBN 0-226-31893-1.
- Kristen J. Gremillion, People, Plants, and Landscapes: Studies in Paleoethnobotany, University of Alabama Press (February 1, 1997), ISBN 0-8173-0827-X.
- Miksicek, C.H., Formation Processes of the Archaeobotanical Record., In: M.B.Schiffer (ed.) Advances in Archaeological Method and Theory 10. Academic Press, New York, (1987) 211-247, ISBN 0-12-003110-8.
- "Association of Environmental Archaeology"
- Steve Archer, "About Phytoliths"
- Terry B. Ball, "Phytolith Literature Review"
- International Work Group for Palaeoethnobotany, "IWGP"
- Integrated Archaeobotanical Research Project,IAR