We detected significant changes in the knowledge of wild food plants in the border region shared by Poland, Lithuania, and Belarus. We observed that most taxa demonstrated a movement of knowledge that includes past, ongoing, and newly learned practices. This can be defined as knowledge in motion, indicating a continuously evolving flow variation. The mentioned plants were of considerable importance in all three countries that were studied. This importance was assessed using the cultural importance index, which quantifies the significance of these plants based on their usage and the continuity of their knowledge (see [44]). Among the most common food taxa recorded were Urtica dioica and Rumex acetosa. Their use in soups was also supported by historical written sources, showing a longstanding tradition in the region (see [36,37,38]: “Viasnoj to, nu što dla supa viasnoj—eta pieršym dziełam, maładaja krapiva. A bolš što jašče. Ščaviel. Ale ščaviel eta paźniej uže. Pieršym dziełam—krapiva. Eta abizacielna. Ščaviel jašče i na zimu stavim” [In spring, well, for soup in spring, the first thing is young nettles. And what else? Sorrel, but sorrel is used later. First of all, nettle. It is a must. We also conserved sorrel for winter] (Belarus, Polish man, 60 years old).

We found that the frequently cited wild berries, such as Vaccinium myrtillus, Rubus idaeus, Fragaria vesca, Vaccinium oxycoccos, and Vaccinium vitis-idaea, have circulated within the three time dimensions with varying intensities. Over time, methods of use and preparation techniques have undergone changes, while the enduring value of these plants remains remarkably high in terms of their utility and continued use (Fig. 7).

The use of wild fruits in motion: a Just gathered Vaccinium myrtillus, Lithuania; b Jam from Vaccinium myrtillus, Belarus; c Drying of Vaccinium myrtillus, Lithuania; d Collecting of Rubus idaeus, Belarus; e Wine from Rubus idaeus, Belarus; f Frozen jam and compote from Rubus idaeus, Belarus; g Recreational tea with Rubus idaeus, Lithuania; h Sauerkraut (fermented cabbage) with Vaccinium oxycoccos, Belarus; i Vaccinium oxycoccos soaked in water for winter, Lithuania; j Drying of Fragaria vesca, Lithuania; k Making jam from Vaccinium vitis-idaea, Poland. Credit: Julia Prakofjewa, 2018–2019

Interestingly, we recorded the essential role of Vaccinium myrtillus during food shortages in Poland during WWII: "[W 1939] … uciekaliśmy, bo tutaj wisiał taki samolot, no samolot wisiał. W powietrzu. Ale słuchamy, krzyczy ktoś, żeby nie iść w tą stroną. Tylko iść, bo tu jeszcze nie ma tych Niemców. A iść w tą stroną. Bo to już Ruskie… To my biegiem i przez ten gościniec. I poszli do tego lasu. Przyszli do tego lasu, Jezus Maria, a nic nie mamy ze sobą. Ale gadali, gadali te ruskie, tylko tego już oni idą, już oni idą i wszystko… A my z sobą tylko krowy mieli… I gotowali. A co? Gotowali kartofla. A ta kartofla, to była taka była… taka malutka była, taka malutka była. No i tu, ta kartofla i z jagodami gotowali. Z czarnymi. Bo tutaj pełno czarnych… Jestem wciąż wdzięczna tym jagodom za to, że nas uratowały" [[In 1939] … we were running away because there was a plane like this hanging here, a plane was hanging here. In the air. But we were listening, someone was shouting not to go down this road. But to use another one, because those Germans weren't here yet. And go down this road. Because it was already the Russians… We ran along this road. And we went into this forest. We got into the woods, Jesus Maria, and we had nothing with us… And we only had cows… But they were talking, they were talking, these Russians, only that they were going, they were going and everything. And we cooked. And what? We cooked potatoes. And these potatoes, they were so … so tiny, so tiny. And here, these potatoes were cooked with blueberries. With blueberries. Because there were a lot of blueberries… I'm still grateful to those blueberries. For saving us all…] (Poland, Polish woman, 92 years old). The same use during WWII was confirmed by other senior interviewees from Poland.

From an ecological standpoint, specific berry species growing in the forests, such as Vaccinium myrtillus, Vaccinium vitis-idaea, Rubus idaeus, and Fragaria vesca, along with synanthropic plants (including certain weeds) like Urtica dioica and Rumex acetosa, demonstrate greater resilience and suitability for use as food plants. Conversely, among non-berry species, there are several whose use has been abandoned over time, such as Pinus sylvestris, Calluna vulgaris, and Oxalis acetosella.

Sharing information about the properties and uses of plants between different ethnic groups often results in heightened awareness, improved utilisation, and more sustainable practices among all local communities. For instance, the flowers of Sambucus nigra were historically fried in batter by Poles (see [37, 63]). During fieldwork, we also documented the same use among Lithuanians in Poland: "Petruk, kap tas vadinasi, juodi tie mūs bezai? Nu aš sakau, aš pavadinimų nežinau. Tokios kekės žydi žiedų, balti… Šeivamedis. Iš laukų. [renka] Jų namie nesodinam niekas… O žiedus tai kepėm. Nu jis kaip nusiima aplinkui toks gražus, kaip grybą pavyzdžiui, tą in kokį prieskonį, in kiaušinį in džiovytus tuos džiūvėsiukus ir an keptuvės. Jis va šitokiu būdu visai gerai kepasi.” [Petruk, how is it called [in Lithuanian], our black bezai? Well, I’m telling you, I do not know the names. Such clusters of white flowers bloom together… Šeivamedis. [They collect] from fields. None of us plants them at home… And flowers we baked. Well, when you pluck it [flower], it is so round and nice, like a mushroom; for example, you put it in some seasonings, into an egg, in breadcrumbs, and into a frying pan. In this way, it cooks pretty well] (Poland, Lithuanian woman, 70 years old). According to our Lithuanian interviewees from Poland, they learned about this particular plant use from a promotion they saw on Polish national TV. As a result, they had difficulty recalling the local name and primarily used the common Polish name. Nowadays, the flowers/fruits of Sambucus nigra are mainly used for making recreational tea or non-alcoholic drinks throughout the border area.

Svanberg et al. [64] suggested that tree sap extraction was predominantly historically practised in regions with abundant Betula spp. and Acer platanoides populations, as these species tend to yield significant quantities of sap. Modern ethnobotanical studies have shown that fresh and processed drinks made from tree sap have had a relatively high informant consensus factor in Belarus, both historically and today [65]. Birch sap has been widely used fresh and fermented in Lithuania for centuries [64]. In the eastern part of Poland, the use of birch trees for sap was widespread in the nineteenth century (see [37]), but by the mid-twentieth century, it was (nearly) obsolete and practised mainly by boys as a form of spring entertainment [36, 64, 66]. The use of Acer platanoides was popular in Belarus and Lithuania but documented as very rare in Poland, mainly occurring in the eastern part. of the country. It did gain popularity after 1945 in areas of north-eastern Poland, where people from present-day Lithuania and Belarus were resettled [64].

Our field research has confirmed the changes recorded in previously published sources. Specifically, in Belarus, we documented a variety of continuous practices of sap preservation (fermentation and pasteurisation), along with its active fresh use. Belarusian interviewees were actively experimenting with adding different ingredients to birch sap in order to change its colour and flavour. For instance, along with the use of Mentha spp. and Ribes nigrum leaves, people were adding slices of different citrus fruits, raisins, citric acid, and even caramel.

In Lithuania, both studied communities were still actively gathering and processing sap. We recorded an equal temporal distribution of DUR between present and past uses. The majority of interviewees confirmed the historical use, namely the fermentation of birch sap with the addition of Avena sativa [67]. They described the whole process very precisely, which, though not practised, still remains in the collective memory: "…su avižom ten būdavo beržų tą sulą kai suleidžia, tai užpila, avižas dėdavo, jos tokią plutą sudaro, sudygsta, kaip atžalos tokios gaunasi avižų ir ta pluta uždengia visą sulą ir jinai rūgsta, ir jinai labai skani" […with oats, they used to make birch sap. After collecting the sap, they used to put oats on top. They made such a crust. Then the oats sprout. Then, the shoots of oats were there as a result. And that crust covered all the sap, and it fermented. It is delicious] (Lithuania, Lithuanian woman, 56 years old). The majority of interviewees from Poland reported the occasional and continuous use of Betula spp. for sap. They mentioned using it mainly as a fresh beverage, which was frozen for the winter but not fermented. Overall, we observed a gradual decline in the use of fermentation techniques in all three countries, albeit to varying degrees. Interviewees from Belarus reported finding the sap available in stores much tastier than the fermented one. Most interviewees stated that they no longer ferment birch sap because they dislike the taste.

Our case studies have revealed a specific flow variation that overlaps between past and continuous uses, which could be recognised as a stagnation of knowledge. While some uses of plants in this flow were predominant in the past and continue to be integral to ongoing traditions (Fig. 8), others have lost their significance for the studied communities, remaining only in the historical written records. In such cases, the plants are still used, but some of their traditional uses have disappeared. For instance, in responses to Polish botanist Józef Rostafiński's (1883) questionnaire, the use of Armoracia rusticana was documented for the preparation of "salad with vinegar" (see [37]). The lexicon of Slavic beliefs and customs written by the Polish ethnographer Adam Fischer in the 1930s reported that this plant was used only in the medicinal domain (see [38]). Nevertheless, our fieldwork results have shown the great cultural importance of Armoracia rusticana among Polish and Lithuanian communities and its predominant uninterrupted use as food. Roots and leaves were used as a popular seasoning for lactofermented cucumbers and meat. More than half of the interviewees emphasised that they still make horseradish relish as a special ritual dish for Easter. The recorded stagnation in the tradition of using this plant can be attributed to several factors, including its gradual disappearance from the cultivated landscape in all three countries [66, 68], as well as the effort involved in making seasoning and the availability of ready-made options in stores: "Nie, chrzan tam dalej. Tam dalej jest, ale już mało go jest. Nie, jego jak robisz, to bardzo łzy leje się. Ja już nie mogę. Wolę kupić w sklepie. Ale dawniej to tak, to dużo go używaliśmy” [No, chrzan is further out there [growing]. It is growing far away, but it is already disappearing. No, while you are making it, you are crying a lot. I cannot do it anymore. I prefer to buy it. But in the past, yes, it was used a lot] (Lithuania, Polish woman, 74 years old).

Wild food plants that are traditionally consumed in the study area: a Preparation of pickled cucumbers with roots of Armoracia rusticana, Lithuania; b Preparation of home-made cheese with Carum carvi, Belarus; c Birch sap, Lithuania; d Sap from Acer platanoides, Belarus; e Vinegar from wild apples, Poland; f Dried sausages with Origanum vulgare, Belarus; g Dried Tilia cordata prepared for recreational tea, Belarus. Credit: Julia Prakofjewa, 2018–2019

At the same time, the use of some taxa was attributed mainly to the past. For instance, the leaves of Acorus calamus and Quercus robur were mentioned in regional historical sources as being placed under bread while baking (see [37, 38]). Our fieldwork confirmed the recorded archival records. Interviewees from all three countries also mentioned the traditional use of fresh or dry leaves of Acer platanoides and Brassica oleracea for this purpose (Fig. 9). However, the tradition of making homemade bread has been gradually disappearing in the study area since the second half of the twentieth century. Nowadays, bread making is rarely mentioned in Poland and Lithuania and only in the context of choosing healthy food that is not bought from a store and with the possibility of using modern baking equipment.

a Homemade bread baked on Acorus calamus leaves; b Drying of cabbage leaves to be used for baking bread and potato pancakes, Poland. Credits: Julia Prakofjewa, Poland, 2019

Stellaria media, Chenopodium album, and Heracleum sphondylium were historically widely used for making sour and non-sour soups in the region (see [36, 37, 63]. However, among our interviewees, these taxa were primarily associated with famine foods from the war and post-war periods. Due to cultural stigmatisation [69] (Menendez-Baceta et al., 2012), nowadays, their use has gradually been abandoned: "I heta (Stellaria media) taksama dobraja raślina. U dziacinstvie pamiataju źbirali, ale nie čuŭ, kab zaraz karystalisia. Heta paśla vajny bolš, jak galadali, baba raskazvała” [And it (Stellaria media) is also a good plant. I remember I collected it as a child, but I have not heard that people are using it now. It was used mainly after the war when people used to starve, my grandmother told me] (Belarus, Polish man, 60 years old).

From an ecological perspective, if widespread cultivation ceases in some species, they will no longer naturalise in the wild, ultimately leading to the disappearance of their use in the long term. For example, Cichorium intybus and Acorus calamus, which rely on human intervention for their spread in a specific area, exhibit this pattern. Conversely, plant species whose expansion into nature is facilitated by cultivation have maintained their historical utilisation in the region over time, such as Armoracia rusticana, Nepeta cataria, and Borago officinalis.

Knowledge decay over time occurs when TEK is no longer valued or passed down to younger generations, leading finally to biocultural diversity loss [70]. In this flow variation, TEK is no longer practised. For example, Vaccinium uliginosum is one of the plants that has gone out of use within the studied region but remains vivid in the memory of our interviewees. Lithuanians and Poles attributed the discontinuation of this practice to the complete disappearance of this plant from the surrounding landscape. Although our interviewees have begun to forget its local name and details of its use, they still distinctly remember the taste and smell of the plant.

Nevertheless, many plants within this domain have historical evidence of use. For instance, Calluna vulgaris was documented as used as an additive to bread within the studied region in the 1930s (see[38]) and in Central Poland [63], which was confirmed by our fieldwork only in Lithuania.

We observed that knowledge decay was often related to the gender division of certain practices. For instance, collecting sap from trees is traditionally considered a male practice within the studied area, while collecting and preserving berries is more of a female practice. Consequently, knowledge can decay without a carrier of the practice: "Vendzili miasa, sała, rybu. Da. Eta haspadar jak byŭ, mieŭ. I kapciŭ i kiłbasy i skvarku. A teraz jaho niama—to niama kamu. Spiecyjalnaja dreva, ale ja nie viedaju jakoje” [We smoked meat, lard, fish. Yes. It was my husband who had the smokehouse. He smoked sausages and lard. And now he is gone—there is no one to smoke. He put meat and smoked it with a special tree, but I do not know which] (Belarus, Lithuanian woman, 82 years old).

The creation of new knowledge regarding the use of wild plants could be recognised as an invention. This may involve developing tools, techniques, or methods for managing natural resources, as well as the formation of new beliefs or attitudes about plants. We observed that the newly acquired knowledge of use and the intention to engage in culinary experimentation are closely connected. As people become more interested in exploring new flavours and ingredients, they are more inclined to seek out new plants to incorporate into their cooking practices. We found that both ethnic groups we studied in Poland and Lithuania exhibit a characteristic trait of having more intention to experiment with new plants.

Our fieldwork showed that new uses originated mainly from popular literature and media in all three countries (Fig. 10). These sources remain essential to and trusted by older generations: "Vo hladzi, heta maja knižačka. Tamaka ŭsio jest. Što tolki rabić—tamaka ŭsie jest. Jak sušyć, jak varyć, jak zamaražvać, jak kansierviravać, jak lačyć, jak što rabić. Tam usie jest" [Look, this is my book. There is everything in it. Everything you can do. How to dry, how to cook, how to freeze, how to conserve, how to cure, how to make. There is everything in this book] (Belarus, Lithuanian woman, 78 years old). Among younger generations with more schooling (aged 40–65), a significant proportion of ethnobotanical knowledge is acquired through written and visual sources, in contrast to the mainly traditional and vertically transmitted knowledge of senior interviewees (aged 65–90). Older interviewees reported using plant-related books in Russian published during the Soviet Union era. The knowledge present in these books and previously widespread in Belarus and Lithuania primarily influenced specific areas such as novel preservation methods (e.g., the freezing of Fragaria vesca) and attributed medicinal properties to food plants (e.g., high vitamin content in Urtica dioica or Rosa sp.). According to our interviewees, the health benefits associated with Cichorium intybus, heavily promoted and advertised in the media in the 1990s, resulted in an increase in its use as a healthy coffee substitute in Poland and Lithuania: “A to jest bardzo fajna roślina. Cykorium. Tak, kawę z cykorią robię. Tylko korzenia. Ale to ja przeczytałam gdzieś, że dobra jest. To (wiedza) nie od mamy, nie” [And it is a very nice plant. Chicory. Yes, I make coffee with chicory. Roots only. But I read somewhere that it is good. It (knowledge) is not from mom, no] (Poland, Polish woman, 50 years old).

a Book about home conserving, Belarus; b Popular newspapers and magazines published in Lithuanian and Russian, introducing the new recipes for conserving and canning mentioned by our interviewees, for sale at a local news-stand, Lithuania; c Local newspapers and calendar as a popular source for new plant knowledge, Belarus. Credits: Julia Prakofjewa, 2018–2019

The process of renewing and restoring TEK that has been lost or forgotten over time may be identified as knowledge revitalisation. In the studied border region, an overarching trend we observed was a general shift towards a return to the use of wild plants for nutrition: "No wiecie co. Konserwantów dużo teraz, ale też spróbujemy wrócić do tej przyrody. I ja, i młodzi ludzie. No to zależy, oczywiście. Najbardziej to młodzi” [You know what. We are using many preservatives now but also trying to return to nature. Both me and the young people. Well, it depends, of course. Mostly the young ones] (Poland, Polish woman, 52 years old). One of the fundamental reasons why interviewees adopted new uses of wild food plants was their benefit to health. This trend is further reinforced by widespread media promotion of the "valuable properties" of wild plants: "To jest aronia. Ja suszę na herbaty. Na wzmocnienia organizmu, bo to ona ma tam różne te. Ale bardzo smaczna jest. Przyniosę ci. Teraz przeczytałam o tym w książce. Aha, i w gazetach teraz to czytałam też” [This is aronia. I dry it for tea. Because it is used to strengthen the body. But it is delicious. I will bring you some. I read about it in a book. Oh, and I also read about that in the newspapers, too] (Poland, Polish woman, 76 years old). Moreover, our research findings highlight that the preservation of plant usage is often observed in species that serve both medicinal and culinary purposes, as exemplified by Tussilago farfara, Leonurus cardiaca, and Hypericum spp.

Highly promoted tea made from the fermented leaves of Epilobium angustifolium (Fig. 11 a-b) (see [23]) was tried and abandoned quickly within the entire studied region. This created the situation that the plant, without being broadly used historically, belongs simultaneously to recently acquired and past temporal dimensions and provides one excellent example of unsuccessful knowledge revitalisation in the region.

Recently acquired uses of wild plants for food in the studied region: a Fermented Epilobium angustifolium for recreational tea, Belarus; b Lithuania; c Syrup from the flowers of Taraxacum officinale, Poland. Credit: Julia Prakofjewa, 2018–2019

The active historical use of Taraxacum officinale in Belarus and Lithuania may be attributed to its promotion in books and women's magazines during Soviet times (see [56, 71]). However, a majority of our interviewees during the 1980s and 1990s attempted to make syrup ("dandelion honey") from the flowers of Taraxacum officinale (Fig. 11c) and now occasionally use the leaves in salads. This illustrates knowledge revitalisation, where innovation occurs at the level of plant parts used, as influenced by the literature. Despite its availability, Taraxacum officinale leaves did not gain popularity in Poland, possibly due to its culinary tradition of avoiding bitter flavours [72].

The movement of knowledge between continuous and recently acquired time domains could be identified as re-invention. This flow variation primarily occurs when ongoing knowledge and practices are adapted or modified to suit changing social, cultural, or economic contexts. For instance, if a traditional practice for preserving wild plants is no longer feasible due to advancements in technology or the availability of resources, re-inventing the practice can help keep the use of wild plants alive.

Specifically, in the study area, the use of the leaves of Aegopodium podagraria for sour and non-sour soups was recorded among Poles in historical sources (see [36, 37, 72]). We documented, in both studied communities, the use of these leaves for soup and salad proportionally more as a recently acquired practice and less as a continuous practice. The same trend was noted for Borago officinalis: “O čia ogurečnik vadinasi. Čia kap neturi agurkų iš pavasaro, tai dedi saloton, tai būna ti kap su agurkais salota. Lapus. Nu [ji naudoja] Ale lietuviškai tai aš nežinau kaip jis vadinas”. [And this one is called ogurečnik. When you don’t have cucumbers in spring, you put it into the salad, and then the salad is like with cucumbers. Leaves [the part used]. Yes [she uses it]. But I do not know what it is called in Lithuanian] (Poland, Lithuanian woman, 73 years old). Historically, the leaves of Borago officinalis were eaten with cream and salt (see [37]). However, we did not record anyone who has abandoned the use of this plant within their lifetime.

In the continuous time dimension, we observed specific plants mentioned by the interviewees as being utilised during their lifetime, leading us to identify this flow variation as knowledge retention. However, these taxa were not recorded in past uses of our sample. Nonetheless, we found historical evidence of their use within neighbouring territories. For example, historical records mentioned the use of Tussilago farfara as a food wrapping in some regions of southwestern Ukraine [36, 63, 72]. Berberis vulgaris was once reported as being consumed raw, cooked in soups, and used as a children's snack by Rostafinski's respondents [72], but throughout Poland, the use of its fruits is common [63]. The continuous consumption of Leonorus cardiaca leaves as a recreational tea was likely related to their medicinal properties. However, the plants recorded here may have resulted from retrospective memory bias. Due to the way people's memories are biased [73], imprecisions, exclusions, or overstatements can occur in their recollections of previous events or occurrences. It is likely that the use of wild plants in this flow variation was limited to certain cultural traditions or ecological settings.

On the basis of the documented environmental discourse, it is reasonable to assume that various driving forces and proximate causes might have impacted the changes in the use of wild food plant knowledge within the studied border region over time. We found that numerous plant taxa remain stagnant, possibly indicating a conservative approach towards their utilisation for nutrition in the region. One of the primary factors possibly driving this pattern is the high resistance of LEK to change. This often results in a reluctance to embrace new technologies or methods that could facilitate more sustainable environmental management. If the knowledge currently available is sufficient to maintain life, there may not be much motivation for practitioners to create new knowledge or discover innovative applications: "To jest (wiedza) wszystko od naszych dziadków. Jak one robili, tak i my robimy" [This is all (knowledge) from our grandparents. As they did, and so we are doing] (Poland, Polish man, 48 years old).

On the other hand, one of the driving forces behind the suspension of the use of wild plants might be the absence of knowledge due to a lack of interest in this topic at a young age. For instance, one 72-year-old Polish woman from Lithuania shared her experience: "Dawniej nie, no jak żyła jego matka, to zbierała roślinki, znała jakie co z tych. Ale ja nie interesowała się tym" [Not in the past, well, when his mother was alive, she collected plants, she knew for what [it was used]. But I was not interested in it]. The majority of interviewees from Belarus and Lithuania emphasised that during their youth they had limited opportunities to learn as they were extensively engaged on collective farms (kolkhozes) and had little time for environmental educational pursuits.

During interviews, some of our senior interviewees struggled to understand our questions concerning the use of fruits, leaves, and especially roots of wild plants as seasonings: "Kareńni ja nie panimaju takoha. Ja toža nie znaju etaha, jak što eci prypravy" [Roots, I don't really understand this. I also don't know what these seasonings are] (Belarus, Polish woman, 73 years old). Most interviewees argued that their parents and grandparents did not use any seasonings in food, which they attributed to widespread poverty throughout the region, especially in the post-WWII period: "A što rańše było, i da vajny i paśla asobienna, znajecie kak ludzi žyli biedna. Nie dumali pra prypravu. Eta sčaz pašła taja pryprava. Tahda nichto pra takoje nie znaŭ. I tak kak było—zažaryš i paješ, i dobra" [And what was before the war, and especially after it, you know how poorly people lived. No one thought about seasonings. Now seasoning is used. Then no one knew about it. And as it was—you cook and eat, and it is good] (Belarus, Polish woman, 94 years old).

Knowledge flow may continue or cease depending on the availability of certain natural resources. Addressing the depletion of resources is one of the key factors attributed to using plants in studied countries with different environmental policies: "Jezus, strasznie zmienił las się, był wielki piękny, powycinali, powycinali, powycinali. A teraz już takie co to teraz. Wo takie, wo takie. Co tam już teraz takiego już nie ma, bo co najlepszy las to wycięty” [Jesus, the forest has changed terribly. It was great and beautiful, but they cut it down, they cut it down, they cut it down. And now, what is it now? There are no such [food] plants there now because the best forest is cut down] (Poland, Polish woman, 91 years old). Intense deforestation, land reclamation, the drainage of wetlands, and other environmental engineering projects have likely resulted in the disappearance of specific plant taxa within the studied region.

During the period between 1955 and 1995, which was characterised by intensive drainage activities in Lithuania and Belarus, significant and contentious actions were undertaken, destroying wetlands [74, 75]. Peat bog vegetation faced severe threats from land reclamation projects and the eutrophication of water bodies, influencing species composition negatively. More specifically, the decreased water levels have caused the proliferation of accompanying shrubs, compromising the vitality of Vaccinium oxycoccos and resulting in a significant decline in its populations [76]. Consequently, due to its extinction from the surrounding environment, the utilisation of this plant has largely been abandoned by our interviewees in Lithuania and Belarus: “Na abłocie eta žuraviny. Chadzili ich, sabirali. Pravalivalisia, tam stanieš vo tak vo na etam vo—a tam vadzička pad spodam. Nu pravalivalisia ludzi. No sabirali. A ciapier užo nima tych bałotaŭ i tych jahad” [Cranberries grew in the swamps. We used to go and collect them. You could fall into the swamp because there is water under the surface. Well, people fell into the swamp but collected. And nowadays, there are no longer any swamps or berries] (Belarus, Lithuanian woman, 74 years old).

When reflecting on the shifts in the utilisation of wild food plants, interviewees mainly highlighted changes in their values and attitudes towards such plants. These changes were particularly noticeable among older interviewees, as certain plants are no longer regarded with the same respect, leading to decreased motivation to collect and consume them. Additionally, alterations in dietary habits among younger generations were also mentioned as a contributing factor. However, the recent dying out of some uses (because they were not trendy anymore) was a popular explanation for the non-use of wild plants in Belarus.

Changes in food preservation methods and the industrialisation of food production during the study period have also impacted the utilisation of wild plants for food. The winter storage of wild plants has been gradually transforming since the introduction of modern technologies to the village in the latter half of the twentieth century. For instance, the introduction of freezers has simplified food preservation. At the same time, traditional techniques like smoking meat and fish and utilising wild plants for preservation are gradually decreasing across the entire region due to the widespread use of refrigerators and the decline of cattle farming.

Our observations revealed that the practice of jam-making is also decreasing in all three countries, as the younger generation perceives it as unhealthy because of its high sugar content. Nevertheless, preserving wild food plants for the winter and not using them later on was quite commonly recorded throughout the studied region. Interviewees indicated that throwing away unused jam made from wild berries is emotionally difficult, but they reluctantly do so. Also, they store new jars for the next season “just in case”. Some interviewees from Belarus and Lithuania were eager to offer us unused preserves. Thus, the practice of preserving plants is more vital than using them for food. This might be explained by traumatic famines in the past [77], which are still present in the minds of the people. The permanent food shortages that widely existed, despite the myth of Soviet food abundance [