(CN) – Ancient Romans relied on long-distance timber trade for the construction of their architecturally stunning empire, according to a study published Wednesday in the journal PLOS ONE.
One of the most sophisticated early societies in history, ancient Rome left behind architectural legacies of great arches, aqueducts, amphitheaters, columns, domes and much more. They developed new engineering techniques and building materials that contributed to the longevity of their monuments like the Colosseum and the basilicas.
But in addition to their extensive use of marble, limestone and concrete, construction of the vast empire also called for a great deal of timber. The wood they used came from different types of trees from across the Roman Empire and far beyond as well, for construction, shipbuilding and firewood.
According to the historian Pliny, deforestation occurred in much of Rome’s conquered lands – forcing rulers to send troops farther out in search of timber until Emperor Hadrian put protective laws in place. How far the troops went for wood has been a mystery due to the erosion of the wood over time; very little has been found with enough integrity to analyze.
Enter lead study author Mauro Bernabei from the National Research Council in Italy, an expert on all aspects relating to wood dating. Bernabei and his colleagues found unusually well-preserved timber samples from this era, allowing them to successfully date and determine their origins and chronology. Their findings have scientists again impressed at the Romans’ ingenuity and highly advanced trade network.
The researchers analyzed 24 samples of oak timber planks excavated from Rome during the construction of a new subway line in 2014-2016. The planks came from a Roman portico, an extravagant walkway leading to the entrance of a building found in the gardens of Via Sannio which belonged to a once lavishly decorated and rich property.
By measuring the tree-ring widths for each plank and running statistical tests to determine average chronology, the authors successfully dated 13 of the recovered planks.
This method of tree-ring dating, also known as dendrochronology, has been used around the world for a peek into historical and environmental events of the past. The growth rings can tell scientists about the climate of the area, rain and drought patterns, the lifespan of the tree and much more. Each tree ring pattern is unique, like a fingerprint, but trees near each other can exhibit similar traits. For example, trees in a forest that experienced a year of increased rainfall would all have a wider ring for that year.
With this new information, the authors compared their dated planks to oak from the Mediterranean and central Europe, where the Romans went looking for timber. They discovered the wood samples from the planks of the Roman portico came from the Jura mountains in eastern France, more than 1,000 miles away. Additionally, 8 of the 13 samples contained sapwood that allowed the researchers to conclude the trees must have been felled sometime between 40 and 60 A.D., and that the planks all came from neighboring trees.
Considering the dimensions of the timber and the great distance it traveled, the researchers believe it is likely that either the ancient Romans or their traders sent the goods floating down the Saône and Rhône rivers in present-day France. From there, they believe the wood was transported over the Mediterranean Sea and up the river Tiber to Rome, though that is only speculation and cannot be confirmed. In fact, the rivers were mostly used as borders rather than for trade purposes.
They also note that obtaining these planks, which were used strictly for the structure of the porticos and not for any aesthetic reason, would have been immensely difficult – an indication that ancient Rome was extremely organized, and their trade network was highly developed.
Bernabei notes: “This study shows that in Roman times, wood from the near-natural woodlands of northeastern France was used for construction purposes in the center of Rome. Considering the distance, calculated to be over 1,700 km, the timber sizes, [and] the means of transportation with all the possible obstacles along the way, our research emphasizes the importance of wood for the Romans and the powerful logistic organization of the Roman society.”