Sabrina Bianco defends her Doctoral Thesis “Fuel economy and environment in the city of Barcelona during historical periods: an archaeological approach based on wood charcoal proxies”

This morning, the defense ceremony of the Doctoral Thesis “Fuel economy and environment in the city of Barcelona during historical periods: an archaeological approach based on wood charcoal proxies”, carried out by Sabrina Bianco, took place at the Sala de Juntes of the Facultat de Geografia i Història of the Universitat de Barcelona.

The thesis was supervised by Dr. Santiago Riera Mora, from the Universitat de Barcelona, Dra. Ethel Allué, researcher at IPHES-CERCA, and Dr. Llorenç Picornell-Gelabert, from the Universitat de les Illes Balears.

The committee consisted of Dra. Alessia D’Auria, from the Università degli Studi di Napoli Federico II, Dr. Jordi Nadal, from the Universitat de Barcelona, and Dra. Yolanda Carrión, from the Universitat de València.

The entire IPHES-CERCA team wishes to congratulate the new doctor!

Doctoral Thesis Summary:

Fuel has been an essential element for the functioning of cities throughout history. Before industrialization, thermal energy depended mainly on the availability of firewood, a fact that turned urban spaces into transforming agents of the forest landscape in their surroundings.

The doctoral thesis of Sabrina Bianco analyzes how the energy needs of Barcelona influenced forests and the environment over more than sixteen centuries, from the foundation of the Roman colony of Barcino to the early modern age (1st–17th centuries AD).

The research is based on the anthracological study of archaeological wood charcoal from 24 urban archaeological interventions carried out in the city of Barcelona, mostly excavated within the framework of preventive archaeology during the last two decades.

Through a diachronic perspective, the thesis reconstructs the evolution of fuel supply systems, forest exploitation models, and landscape transformations linked to urban growth. The study sets out three main objectives:

• To identify the taxonomic composition of the fuel used in domestic, productive, and ritual contexts.
• To reconstruct the characteristics of the exploited forests and their evolution over time.
• To analyze forest management and firewood extraction practices based on dendro-anthracological studies applied mainly to deciduous oak and Aleppo pine.

The results show a progressive evolution of energy supply strategies. During the Roman period, a relatively stable and sustainable system predominated, based mainly on holm oak forests and local shrub species. The stability observed over six centuries suggests an efficient organization of the fuel supply. The occasional use of pruning remains from ornamental and fruit trees has also been documented, evidencing the presence of gardens and agricultural spaces in the surroundings of the city.

In funerary contexts, more selective practices in the use of firewood have been identified. Particularly noteworthy is the use of mature deciduous oak logs in cremation pyres during the 1st century AD, as well as the selection of certain species for their symbolic, aromatic, or decorative properties.

From the High Middle Ages onwards, significant transformations related to forest degradation and the intensification of agricultural and livestock activities are detected. The reduction in the exploitation of holm oaks and the increased use of heliophilous shrubs indicate a profound transformation of forest landscapes. In parallel, the presence of pruning remains from vineyards, olive trees, and other fruit trees grows, reflecting the expansion of arboriculture in the plain of Barcelona.

Since the Late Middle Ages, the city has increased fuel imports to compensate for the deterioration of local resources. The increased use of holm oaks, oaks, and other species coming from more distant areas evidences the progressive integration of Barcelona into wider regional supply networks and the growing impact of urban energy needs on the territory.

Overall, the thesis shows how urban development generated a progressive transformation of the forest landscapes surrounding Barcelona, from a territory initially dominated by holm oak groves to more anthropized landscapes characterized by secondary vegetation and a growing presence of Aleppo pine.

This research also highlights the great potential of urban anthracology, combined with archaeobotanical, paleoenvironmental, and historical data, to understand the relationships between human societies and the environment, as well as the management of natural resources in pre-industrial urban contexts.