description
- Climate change is predicted to negatively impact global agriculture, and if we are to prevent systemic crop failure, it is urgent to do all we can to better understand crop adaptability and the agriculture management interventions which may be required. While we often think of the impact of climate change for today and the future, prehistoric societies also experienced major variations in the climate. In this project we investigate these past changes using science-based archaeology to understand how ancient farming communities and their crops responded to climate variations. This information about agriculture in the past will help the scientific community better understand the risks we may face and possible responses which may be necessary to manage our agriculture systems. HIDDEN FRONTIERS focuses on past agriculture in the circum-Alpine region. The Alps--and specifically their world-famous prehistoric Alpine pile dwellings--provide the perfect opportunity to evaluate how crops responded to variation in climate. These sites provide three key resources to understand how climate impacts agriculture: - Preservation of plant remains and their DNA. The Alps possess some of Europe's most pristine ancient plant specimens, thanks to underwater preservation at many of the 111 UNESCO-listed pile dwelling sites. These sites, also referred to as the ancient Lake Villages, were settled by farmers between the fifth and first millennia BC, spanning the Neolithic, Bronze Age and Iron Age. The sites were built on wooden piles driven into marshy land, but over time the sites were abandoned and flooded by the lakes upon which they were constructed. Due to the underwater conditions, organic materials are exceptionally well preserved, allowing archaeologists to identify seeds and chaff to infer which crops were farmed in different periods. This project takes the next step, using state-of-the-art methods to recover ancient DNA directly from the remains of species like wheat and flax, and then analyse this DNA to understand a detailed history of crop movement, replacement and adaptation. - Dating. The excellent organic preservation of tree trunks at the pile dwelling sites enables high-resolution dating rarely afforded in prehistoric archaeology. Using "dendrochronology", researchers have carefully characterised patterns of tree ring growth, allowing for the sites to be dated on the scale of decades, which exceed the resolution normally provided by radiocarbon dating. These dates allow this project to link archaeological plant remains into a tight chronology informed by past climate data. - Paleoclimate reconstructions. The circum-Alpine lakes on which the pile dwelling sites were constructed have been carefully studied by climate researchers for decades. Using sediment cores from the lakes, researchers have been able to track local changes in the climate by measuring stable isotopes, identifying pollen types and observing different types of freshwater insects. These detailed reconstructions of past climates allow this project to fully appreciate the environmental conditions under which different crops were grown and evaluate the genetic impact when the climate changed. Through this remarkable combination of resources, HIDDEN FRONTIERS explores the interplay of climate and society to understand the story of Alpine Lake Villages and their food production systems. By analysing ancient DNA from the crops, the team identifies if local crop lineages went extinct during challenging climate phases. In addition, by looking at specific genes in these lineages, we come to understand how quickly crops can adapt and what genes are most responsible for new adaptations. These findings will be instrumental in predicting how our agricultural system may respond to climate change, thereby allowing our society to take the necessary steps to ensure our crops can feed many generations in the future.