Knowledge in motion: temporal dynamics of wild food plant use in the Polish-Lithuanian-Belarusian border region

Background: Understanding how Local Ecological Knowledge (LEK) evolves over time is crucial for fostering social and environmental responsibility. This study aims to develop a conceptual model of plant knowledge circulation, providing insights into the temporal dynamics of LEK in the Polish-Lithuanian-Belarusian border region. It explores the key patterns and driving forces behind changes in the use of wild plants for food. Methods: Field research was conducted in 60 rural settlements across Podlasie Voivodeship (Poland), Vilnius Region (Lithuania), and Hrodna Region (Belarus). This included 200 semi-structured interviews and participant observation among two local communities, Lithuanians and Poles. To assess the temporal dynamics of wild food use, we performed a cross-ethnic, cross-border analysis over time, dividing the data into three major temporal dimensions: past, continuous, and recently acquired uses. Results: Of the 72 wild plant taxa reported by Poles or Lithuanians in the Polish-Lithuanian-Belarusian borderland, 47 were continuously used for food, 58 were utilised in the past, and 41 were recently acquired. Cross-country trends were similar, with Poland showing more past uses. Diachronic comparisons between Poles and Lithuanians in each studied country revealed no significant differences. Recently acquired taxa overlapped considerably with those used continuously and in the past. The most diversely utilised taxa showed the greatest overlaps. By observing the movement of specific plant taxa within various time dimensions, we distinguished overlapping flow variations: retention (3 taxa), decay (11), invention (8), stagnation (17), revitalisation (6), re-invention (3), and knowledge in motion (24). Shifts in the use of wild food plants were influenced by changes in environmental conditions, governmental policies, cultural practices, and economic factors. Conclusion: The findings of this study have important implications for improving methods of tracking changes in LEK and enhancing our understanding of the relationship between people and nature. Our results underscore the importance of considering knowledge circulation over time in different directions. Recognising the various stages of knowledge circulation might help in pursuing sustainable solutions that balance the needs of human communities with environmental protection.