Introduction

Imagine 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 For instance, early pine forests (Loblolly and Virginia Pines) may have been replaced by deciduous hardwood forests (Oak, Hickory, Walnut).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.

» 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.

» Wood & Charcoal Anatomy Basics

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. 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.