Periodic Reporting for period 1 - WoodTiMe (The Wood as Time Machine: interdisciplinary approach to study post-medieval human-environment interactions where Atlantic meets the Mediterranean)
Okres sprawozdawczy: 2021-09-01 do 2023-08-31
Under the "WoodTime" project, we examined the consequences of this interaction by analysing wood samples sourced from ancient forests that still exist today, as well as archaeological sites, including historic structures constructed using wood. Wood was chosen as the primary subject of study because it holds valuable insights into a range of topics, such as historical forest management practices, shifts in forest dynamics influenced by human activity, climate variations, and logging practices, among others. Furthermore, wood contains information about the ecological conditions of the areas from which the timber originates. Additionally, the historical connections between North Africa and Southern Europe, both socially and administratively, are reflected in the timber used for construction. For instance, the use of Atlantic cedar timber in Andalusia suggests a historical wood trade and transportation network across the Gibraltar Strait. The "WoodTime" project aimed to unlock the wealth of information concealed within timber using non-destructive methods. This endeavour provided an exceptional opportunity to study past relationship between human activities and forest ecosystems, offering high-resolution insights through detailed analyses of timber structure, as well as its chemical and molecular composition.
The main objectives of the research project were:
1. To understand the forest historical exploitation in Southern Spain and Morocco and its relationship with the past and current forest dynamics through tree-ring width analyses in cooperation with human, historical and geographical studies.
2. To explore the potential of deriving post-medieval ecological and societal information from the ample wood evidence preserved in historical timber, with a focus on forest history and environmental changes.
3. Use emerging techniques of wood anatomy, blue intensity, DNA, elemental composition, and stable isotopes to develop novel dendroscapes tools for timber provenancing.
For the collection of wood samples from living trees, several fieldwork efforts were organized:
- A fieldwork expedition in Cazorla Natural Park (Spain) was conducted to gather wood cores from Black pine trees. Over the course of five days, 97 trees were cored, with the oldest one dating back to 1121 AD.
- Fieldwork in the Middle and High Atlas Mountains in Morocco was carried out to collect Atlantic cedar tree cores (80 cores from 42 trees).
- Additional fieldwork took place in Mágina National Park and Sierra Nevada National Parks (Spain) to acquire more black pine samples (30 in total) and broaden the data source area.
Historical wood, on the other hand, was collected from three buildings: Colegial del Salvador (Seville), Hospital Real (Granada), and Castillo de La Calahorra, the latter being a castle situated near Sierra Nevada in Andalusia.
The collected materials underwent a series of analytical techniques, including:
- Tree-ring width analyses, which involved measuring the width of rings in the samples and creating ring-width time-series (chronologies) containing information on the historical forest and climate history.
- Dendrochemical analyses, utilizing an ITRAX machine to measure the relative concentration of 18 chemical elements and subsequently creating chemical time series.
- Dendrogenetic analyses of samples from living trees and historical buildings conducted during the secondment period at the University of Copenhagen (Denmark).
The data obtained was used to test whether novel approaches added value to archaeological research and improved our understanding of past forest exploitation. The results clearly demonstrated that dendrochemical analyses could overcome the limitations of more conventional tree-ring width-based analyses and pinpoint the historical timber's origin with greater precision. Specifically, it was discovered that several beams from Colegial del Salvador church originated from the middle elevation of Cazorla mountains in Spain, information that tree-ring research alone could not provide.
Genetic analyses confirmed challenges encountered when extracting archaeological DNA from wood, as it is often heavily degraded, and only microbial DNA is usually found. However, genetic analyses of Black pines from Southern Spain showed great potential for using this technique.
The obtained results were widely shared at several international conferences in the Netherlands, Germany, and Portugal, as well as during local workshops in Andalusia. The latter is particularly significant because the research focuses on local history, and the results are highly relevant to local foresters.
Furthermore, this dataset can also serve in paleoclimatic studies, aiding in the reconstruction of major geomorphological events and assessing chemical pollution, among other applications. From a societal perspective, understanding changes in specific chemical elements within trees can contribute to better adaptation to climate change, particularly in the fields of forestry and related industries.