Pollen. I am sure just reading the word makes many a reader’s nose itch and eyes water. Seasonal allergies are the bane of many an existence this time of year, including my own. But besides the obvious environmental need to allow plant species to reproduce, pollen can also serve a special purpose for archaeologists.
Palynology is the ‘study of dust or of particles that are strewn’. Previous Dig It articles have discussed sediment and stratigraphy (the layering of sediments) used to interpret archaeological sites. The same principal can apply to palynology; pollen grains get dispersed in the wind at certain times of year, accumulating both in water and on the ground surface. The landforms build and change over time, trapping the pollen spores like layers of cake being saved for later, with each layer capturing a unique signature for the plants present and releasing pollen at that time. Taking column samples (basically a vertical cylindrical column of dirt) in an archaeological site, and having a professional analyze the pollen grains trapped in those layers, can tell us quite a bit about that archaeological site and the conditions surrounding the people who lived there.
A well-trained expert will examine the tiny pollen particles under a microscope and tell us what plant species they came from. This is especially interesting because the plants we see present in an area in any given area now are not the same as they have been across time. Some grasslands were once forested, and some forests were once wetlands or lakes, and often vice versa. We can see how a single location has undergone environmental transformations through time based on the plant species present, and how that affected people’s behaviour and the options available to them for food and shelter. It’s tough to find bison to hunt in an area that’s heavily wooded, and it’s hard to build homes using wood in areas with no forest!
The seasonality of a site, the time of year it was occupied, is another important factor that can be determined through palynology. We know plants are generally only available certain times of year and seeing evidence (or a lack of evidence) of these plants in sediment samples from an archaeological site can tell us what season(s) that location was utilized in the past. This in turn can show human migration patterns, on both large and small scale.
Pollen analysis can also show the importation of plant species and trace the domestication and cultivation of plants if pollen identified within an archaeological site doesn’t appear to correspond to an environmental event. And if there has been domestication of animals, pollen can also tell us what people were feeding their livestock.
Skara Brae, an ancient site in Scotland where pollen analysis has shown pollen grains that represent the cultivation of plant species that may have been used to brew beer thousands of years ago.
And last, but certainly not least, palynology can bring back recipes thought lost forever. While doing some digging for this article, I came across a story that shows the testament and grit of the human spirit… In the Middle Ages in Europe the two remaining brewers of an ancient Celtic heather ale chose death over revealing the secret ale recipe to inquisitive raiders. And so, the recipe died with them. But many hundreds of years later, a shard of pottery from an archaeological site in Scotland contained pollen grains that allowed palynologist Dr. Moffat to identify the components of said heather ale. While he wasn’t able to determine the proportions of each ingredient from this analysis, he experimented and brewed what he described as ‘a very drinkable alcohol, comparing quite favourably with beers available in various Edinburgh hostelries.’ A Scottish distillery has been further experimenting with the recipe in the hopes of making it commercially available.
So, while you sneeze and sniffle and curse the pollen blowing about in the wind, give a thought to how future archaeologists will use palynology to interpret our present day lives, and maybe even brew an ale or two.