Studying Ancient Plant and Seed Remains
Archaeobotany, Paleoecology, and Paleoethnobotany
Mar 22, 2009
Archaeobotany examines plant remains found at archaeological sites. These remains can be pieces of fiber, phytoliths, seeds, and pollen.
Paleoecology is the study of past ecological landscapes and landscape reconstruction. This science uses ice coring of frozen ponds and lakes, as well as coring of the bottoms of tropical lakes and waterways to see what pollen has fallen into the sediment and left undisturbed over time, sometimes back thousands of years.
Paleoethnobotany investigates the archaeological remains of plants to see how humans interacted with the flora of a given region (Hastorf and Popper, Current Paleoethnobotany: Analytical Methods and Cultural Interpretations of Archaeological Plant Remains, Chicago:The University of Chicago Press, 1988, pp. ix). In short, each of these specializations looks at what plant remains are still there and what insight they could provide into past climates, landscapes, land usage, and people in a given region.
Archaeobotany, Paleoecology, and Paleoethnobotany and Preservation
If the preservation is ideal (if the soil is left undisturbed, if the soil pH is not too acidic or too basic), leaves, stems, seeds, flowers, root fibers, etc. can be found preserved. If it is a funeral burial, remnants of plants interred with the individual may be found, or evidence of past existence of flowers that did not preserve can be found on clothing, bones, etc.) If it is in a cave, plant offerings or food reserves may be located.
In the bottom of a lake, layers of annual pollen deposits can be found to see if the surrounding forests and fields have served different use functions or been populated by different floral and tree species than currently exist. If preservation is not as strong, it is not necessarily impossible to try to do these scientific investigations. The results may be skewed, not truly representative, and like most of the archaeological record, incomplete and up for multiple interpretations.
Collecting Archaeobotanical and Paleoecological Samples
Often times, the soil is collected at an archaeological site, placed in proper plastic bags and made sure not to collect fungal blooms or be cross-contaminated with contemporary plant material and pollen spores. This is a dry soil sample. These containers of soil samples are properly labeled with the coordinates they were taken from and are weighed, all to preserve the records for later comparison with other material excavated at the site.
The soil is then taken to a scientist with formal training in archaeobotany who works in a professional laboratory. If the soil is taken through coring, it is a wet sample, and must be taken care of in a different manner. The core as it is removed, is slid out in one large, unbroken piece onto saran wrap or foil and promptly wrapped, with the coordinates/depth of coring sample recorded on the exterior. The temperature needs to be controlled where these samples are kept so as to not accelerate growths or conversely destruction of organic remains.
Archaeobotanical and Paleoecological Laboratory Work
The soil is processed so as to remove excess humic acid and other elements that interfere with the scientist's ability to count the pollen spores on slide mounts. Additionally, the scientists often introduce a non-native species of pollen (called a spike) to the sample to be able to better approximate the overabundance and the true density of different genera and species in a given specimen.
Once the soil sample is thoroughly processed, the slides are examined and the pollen types counted. This is typically done with a microscope at a high magnification. The slide mounts are only containing the microfauna remains (phytoliths, pollen, carbon which is evidence of burned material). The macrofauna is filtered or sieved out in the last step of processing and placed to the side.
The macrofauna includes things like fibers, leaves, nuts, berries, and sometimes wood. The macrofauna material is observed through larger microscopes. The samples are photographed, measured, drawn pictorially, and graphed.
Things like soil stratigraphies can be mapped so as to see sediment deposition differences across a site, or over time. Prominent pollen strata can sometimes also be correlated with specific time periods or epochs. These can be glaciations or could be times of site inhabitance and abandonment.
In closing, this detailed use of scientific inquiry can allow archaeologists and ecologists further insight into past landscapes and past human behavior at a site. This can help in reconstructing diets, determining trade routes and migration patterns, and even help in determining what resources were available and how they were utilized by huma
