being able to go back in time and see what a forest looked like
in the past, say just before Captain Smith’s arrival in
the Chesapeake. You would be able to understand the ecology of
the forest (what types of trees grew there) during the early 17th
century and how the types of trees have changed over time (plant
succession) to the present. For instance, early pine forests (Loblolly
and Virginia Pines) may have been replaced by deciduous hardwood
forests (Oak, Hickory, Walnut). These changes may be due to climate
shifts or from human intervention, such as Native Americans and
the Jamestown colonists and their followers. Also imagine finding
wood boards from a 17th-century archeological excavation. Are
they from corner posts supporting a building, or the linings of
a root cellar? If the wood is Black Locust (Robinia pseudoacacia),
it is most likely a corner post, while if it is Eastern Red Cedar
it may be part of a subterranean room like a root cellar.
Making these determinations is possible using wood & charcoal identification
via optical microscopy. The establishment of a teaching and reference
collection and the research generated by it, in conjunction with
the large holdings of archaeological charcoal (both historic and
prehistoric) by the Maryland Archaeological Conservation Lab (MAC
Lab) is highly significant to the understanding of the ecology,
forest composition and forest succession of Maryland. It has indicated
that the forest composition has changed little since recent prehistoric
times. Charcoal identification is also a simple, effective, novel,
hands-on way of demonstrating the concepts of forest succession
and ecological disturbance through human intervention to the general
public. The main value of wood identification will be the study
of the historical use of wooden objects and structures. The main
value of charcoal identification is to determine forest composition
and possible ecosystem succession due to environmental impacts
by Native Americans and European colonists.
Why Do Archaeologists Find Charcoal and
Wood Remains in Archaeological Sites?
When humans build fires they use wood from their immediate surroundings.
When the fires go out, incompletely burned fragments remain as
charcoal. Charcoal, commonly found in archaeological contexts,
can be used to identify trees found at the site. Charcoal is partly
burned (charred) wood, consisting mainly of carbon, sometimes
found in situ as burned timbers of buildings and other
structures or in hearths, but more frequently widely disseminated
through the deposits. Charcoal persists in the archaeological
record because it doesn’t decompose biologically. It is
largely unaffected by wood destroying organisms (bacteria, fungi,
insects and other invertebrates). As a result, it will persist
in soil for long periods of time and often turns up in archaeological
excavations as components from old hearth or camp fires and from
the postholes of burned buildings. The identification of such
charcoal is essential to provide a record of paleo-climatic changes
and has significance as evidence of ancient cultural practices.
Identification is possible because the anatomical features of
the wood remain intact during the carbonization process and microscopic
wood identification is recognized as a valid identification process. Click here to view chart of charcoal collected and identified from the artifact inventory of five archaeological
sites, stored here at the MAC Lab.
Wood samples are much less likely to be found, as their chances of
avoiding decay are small. The most common types of archaeological
wood found have either chemical protection (naturally, like cedars
and hard pine, or man-made, like creosote treated timbers) or
are closely associated with corroding metal.
to Use this Website
The development of this website was
generously funded by a matching grant from the Chesapeake Bay
Gateways Network in partnership with the US National Park Service. http://www.baygateways.net.
The content for this website was developed by Harry A. Alden,
Ph.D. The MAC Lab would like to acknowledge Patricia Samford and
Edward Chaney for their assistance with the project, and Sharon
Raftery for the web page design.