5.1. Forest-connected settlements with their environmental context and consequences
Permanent forest colonization is one of the factors of settlement landscape that usually appears relatively late. In Central Europe, the first forest settlements were associated with the development of the so-called German law system (Bartlett 1993). However, so far some observations show that the biggest quantum leap came much later - in the 17th and 18th centuries (Heymanowski 1969; Śląski 1954). In fact, permanent forest colonization must be treated as a long-term effect of progressive colonization and landscape opening by human societies, as well as a consequence of the rapid development of industrial techniques and societal changes (Czerwiński et al. 2021; Izdebski et al. 2022; Kizwalter 2020; Słowiński et al. 2021). With each passing century, the forest cover shrank, due to progressive felling of trees for agriculture and livestock grazing, and also disproportionately slower regeneration of natural tree stands (Żabko-Potopowicz 1965). The export of forest products to Western Europe in the 15th and 16th century was caused by the intensive development of this part of the continent, resulting in drastic shrinkage of forest cover in countries such as England, France, and the Netherlands (Jedwab et al. 2020; Kaplan et al. 2009; Warde 2006). As the demand for wood grew, people began to search for new markets that could supply this valuable raw material. Furthermore, rapid economic development necessitated not only consistent food supply but also materials for construction and crafting for the manufacture of everyday products—both ordinary and luxurious (Żabko-Potopowicz 1965).
The social development in Western Europe paved the way for the exploitation of primeval forests in Central and Eastern Europe. A large number of forests in the Vistula River basin were cut down during the 15th and 16th century, which triggered discussions on their protection. For instance, Queen Constance of Austria (1588–1631), wife of Polish King Sigismund III Vasa, issued a decree stipulating the protection of Tuchola Forest (Pol. Bory Tucholskie) located in North Poland (Słowiński et al. 2021). The lack or inadequate control of tenants who took over individual estates (royal, noble, and ecclesiastical) for a specific period, paying an annual fee to the owners, and exploited the forest stands beyond their means, did not make matters any easier (Związek, Leńczuk and Zachara-Związek, in prep.). The so-called forest entry rights granted to the nobility by Polish monarchs were also detrimental. Using these privileges, the nobles harvested timber without interference from forestry officials. Jan Kochanowski, a Renaissance poet, described the intensive forest clearing in the Republic of Poland in his poem emphasizing the construction of ironworks, forge burning of charcoal, and production of tar and tar pitch (Kochanowski 1930).
Due to the scarcity of statistical records describing the scale of deforestation in Polish lands in the Middle Ages and modern times, we relied on indirect data. Sources indicating an increase in cultivated acreage with a simultaneous shrinkage of forest cover are relevant in this scenario (Gidaszewski et al. 2013). According to tax documents from the 16th century, between 1533 and 1569, there was a 150–250% increase in cultivated area in the eastern part of the then Crown of Poland and an 80–100% increase in taxed cultivated area in the central part (in Greater Poland and Cuyavia) (Boroda 2016). This has been interpreted primarily through the changes associated with the development of settlement structures in the successive stages of internal colonization of Early Modern Poland (Kowalczyk-Heyman and Gochna 2018) or economic issues conceived through readaptation of agricultural wastelands (the so-called empty fields, Lat. mansi deserti) as well as the development of the nobleman’s manor (Boroda 2016). However, it should be highlighted that researchers who have explored Poland’s economic history have focused only on assessing cereal commodity export, usually overlooking the importance of forest commodities in their macroanalyses (Małowist 2006). Nevertheless, the geographic features of the studied areas and their proximity to the Vistula river basin point to an intensive exploitation of local primeval forests at first and only in the next stage the encroachment of regular settlement structures into the forests (Żywirska 1973).
In general, two basic types of forest settlements can be distinguished in various historical sources. The first group include seasonal settlements, which were not permanently inhabited. Most often, these were the shacks of coal burners, barn-keepers, or peasants gathering hay from the fields located in the middle of the forests. These settlements are difficult to track in written sources, but at times they can be located on old maps. Researchers frequently presume their existence based on the macro- or microtoponymic layer. The second group includes rural or industrial settlements located on the settlement peripheries. Nevertheless, in this case, we did not analyze cities and towns, which have a considerably varied impact on the surrounding environment.
In the Polish literature, the practice of forest exploitation is referred to as ‘predatory’ until the introduction of modern forest management in the 18th and 19th centuries (Broda 2000). However, this term is misleading and creates unnecessary antagonism, while implying the superiority of conventional forest management in the context of timber harvesting. The term ‘selective management’ would be more appropriate as in those times forests were used mainly for harvesting the finest (i.e., largest, straightest, and most valued species) of trees. Moreover, it is not true that the past societies had no concerns about the environmental consequences of overexploitation of biomass (Związek 2017). However, in many cases, the latter was fully intentional due to the desire for obtaining the highest possible income from estates leased for a certain period. Forest exploitation in the preindustrial era, at the scale of the three important groups of economic activity, not only led to the emergence of mid-forest clearings or breaking (and thus extension) of forest borders, but also caused changes in the species composition of individual tree stands.
5.2. Clearing of forest areas for timber harvesting
Oikonyms related to forest clearing can be divided into two subcategories. The first category includes names (i.a. buda, kopanina, łaz, and żar) indicating management resulting in the formation of mid-forest clearings (Fig. 3, 4). They were known to be established as a result of tree felling for charcoal burning, or for tar or ash production, or due to natural factors such as windstorms, fires, or insect outbreaks. In modern times, these were frequently used as a natural source of hay for locals, and animals also grazed on them (Wawrzyńczyk 1962). Initially, simple huts were built in these locations, but with time permanent settlements were established and inhabited by people—dwellers and builders—living on the margins of the contemporary society. Both dwellers and builders earned their living by felling trees, burning tar, and making ashes. The activity of the builders in modern times led to the clearing of vast areas of old tree stands throughout the First Polish Republic (Heymanowski 1969g 2021). Interestingly, these people, who were living away from the rest of society, were not well received. At the turn of the 18th and 19th centuries, they were often referred to as idlers, scoundrels, and criminals leading an adventurous life in the forests (Fig. 5), (Skarbek, 1827).
Between the late 15th and the end of the 16th century, timber trade on the territory of the Polish Crown reached its peak (Żabko-Potopowicz 1965). The areas of Mazovia and Central and Lesser Poland (Pol. Małopolska) (places around Cracow, contemporary capital city) were heavily exploited (Fig. 3). According to researchers dealing with the subject of trade in forest products, the exported goods can be divided into two basic groups.
The first group was referred to as productive resource (used to build ships, masts, buildings, barrels, chests, and other products), and the second as firewood (Żabko-Potopowicz 1965). Nonetheless, in the recent dendrochronological research showed that wood obtained from the areas of Poland and the Grand Duchy of Lithuania was used in arts and crafts in Western Europe (Daly and Tyers 2022; Haneca et al. 2005; Wazny 2002). Based on the evidence collected so far, it can be concluded that at the turn of the Middle Ages and Early Modern times the Polish and Lithuanian lands supplied Western Europe with basic forestry goods, thereby promoting its rapid development. However, this state of affairs did not last long, as later (especially in the 17th century), Sweden became a monopolist in this market, entering the most dynamic phase in the development of its statehood in the Early Modern era (von Sundberg et al. 1995).
The second category consists of all names associated with tree felling for raw materials, such as timber logs, firewood, or other forestry semifinished products. These include all oikonyms with word roots such as drew, piła, rąb/ręb, and trzeb. Wood was not only harvested by people for their own use, but, above all, it was floated down the waterways—most often in the form of raw (Pol. kłodzina) or pretreated logs (Pol. dyle). These logs were divided into several categories (Rybarski 1928):
- stave (used for building barrels for storing food products);
- Fassholz (Pol. wasiłka), used for making barrels for storing alcoholic beverages;
- Pienholz (Pol. Pipełki), used for making large barrels;
- wańczos and Knarholz, boards used for building tables, tabletops, and larger items;
One should note that the abovementioned semifinished products were usually made from more valuable deciduous trees such as oak or ash (Samojlik 2006).
Environmental consequences
Anthropogenic deforestation, which was usually associated with timber harvesting or opening of the landscape in the direct catchment of wetlands or lakes for agriculture, has a significant impact on these ecosystems (Feurdean et al. 2020; Kittel et al. 2020; Kruczkowska et al. 2021; Lamentowicz et al. 2019b; Łuców et al. 2021; Słowiński et al. 2021). Firstly, most of these ecosystems are located in depressions in the landscape, which forces slope processes (Butz et al. 2017; Ott et al. 2017; Poraj-Górska et al. 2017; Zawisza et al. 2019; Żarczyński et al. 2019). As a result, opening of the landscape by felling, burning, or wind throwing can cause erosion and denudation on the slope, as well as chemical denudation (its intensity is dependent on the species structure). Due to landscape opening and consequently erosion downslope, dust and nutrients are delivered to basins, causing eutrophication (Dietze et al. 2016; Karpińska-Kołaczek et al. 2014; Kołaczek et al. 2013; Mroczkowska et al. 2021; Słowiński et al. 2021). Depending on their magnitude and the resilience of the ecosystem, these disturbances (e.g., deforestation caused by logging or fire) can trigger a cascade of events (Fialkiewicz-Koziel et al. 2016; Graham et al. 2021; Kinder et al. 2019; Łuców et al. 2021; Mroczkowska et al. 2021; Poraj-Górska et al. 2021). These events, in turn, may potentially affect the transformation of vegetation cover, change trophic status, and ultimately affect the functioning of ecosystems, shifting their ecological state (Lamentowicz et al. 2019a; Zawisza et al. 2019).
5.3. Extraction and processing of raw materials
Civilization of the Middle Ages and Early Modern period required increased volumes of processed iron raw material of high quality (Sigaut 1998). This in turn escalated tree felling for timber, the basic raw material providing energy for steel production (Kander et al. 2014). Steel was commonly traded in the Polish lands in the form of iron bars or rails (Fig. 6), (Rybarski 1928). Raw material production was carried out in forges. These were settlement units that interfered with the forest landscape, as these formed highly developed hinterlands of a more permanent nature around them (Crossley, 1975; Union, 2017). Forges were widespread in the Polish lands already in the late Middle Ages and increasing in number in each succeeding century (Guldon 1974; Kuraś 1959; Laberschek 1996; Zientara 1954). In addition to the essential fuel (charcoal), forges required access to iron raw material, which could be (especially in Pomerania) imported from countries such as Sweden (Kiarszys 2015), or (more commonly) obtained from the local deposits of the so-called meadow iron. Thus, the construction of a forge in a given area was determined mainly by the access to meadow iron (Ratajczak and Skoczylas 1999), flowing water for building a water mill, and finally, deciduous trees for firing energetically caloric charcoal (Brykała and Podgórski 2020; Smil 2017).
Papers issued by landowners to forges often allowed unrestricted exploitation of the surrounding natural environment (Kowalczyk-Heyman 2017). Water-powered forges usually had three water wheels, one for driving the hammer that crushed the ore, one for the bellows, and the third one, hammer, for forging iron bars (Zientara 1954). The complexity of these sites is apparent in the economic inventories describing the personnel working at such sites. Coal burners, smokers, blacksmiths, and washers were among the tax sources identified from the 16th-century records (Związek 2017). Forge works were mostly constructed remote from rural settlements. This forced the landowners to provide limonite- processing workers, in order to establish an adequate economic base in the form of a workforce engaged in crop cultivation or animal husbandry (Muszyńska 2012). The expense of establishing such an industrial plant was high enough to abandon it once the raw material was exhausted. Hence, forge settlements were transformed over time into regular agricultural villages, while the workshop used for crushing and processing bog ore was converted either into simple water mills producing flour, malt or specialized cloth-producing facilities.
In the Late Modern period (i.e., 16th–17th centuries), glassmaking started to flourish in the Polish lands, supplying local markets with poor-quality raw material in the form of glass and simple vessels (Bis 2020; Mucha 1991, 2000; Wyrobisz 1968). While forges tended to remain in their location, glassworks migrated from site to site, due to the exploitation of the nearby wood resources (Černá and Tomková 2017). The first mention of glassworks in the Polish lands appeared in written sources at the end of the 14th century (Wyrobisz 1968). Glassworks were located in environments that had favorable conditions for production. The most important determinants of these conditions were the occurrence of quartz sand deposits (outwash plains, also called sandurs) in the immediate vicinity, and proximity of large forest complexes and water reservoirs or rivers. Similar to forges, glassworks were located in areas rich in high-energy wood, especially deciduous species. The most desired wood material was beechwood needed (in the form of ash) for glass production (Mucha 1984). Water, on the other hand, was used to rinse sand for eliminating components that can reduce the quality of the raw material produced. Sand was a major source of silica, while ash contained potassium, calcium, and magnesium compounds (Markiewicz 2009; Markiewicz 2014; Rubnikowicz 1995). Initially, forest smelters operated for a relatively short time. In the Middle Ages, contracts for glass producing and timber harvesting sites were signed up for a term of 15 years. When the forest in proximity was cut down, the habitats were abandoned, and glassworkers moved to a new, not particularly remote location. In some cases, they continued to operate in the same place for several decades (Markiewicz 2014).
Tar production was another branch of forestry that used wood as a raw material (Broda 1959). Tar was obtained by burning wood (mainly pine) in the presence of a small amount of air. The obtained product was used mainly as an impregnating agent for wood and to seal ship hulls. Birch tar was also used as a disinfectant.
Environmental consequences
Initially, clay-lined earth pits were used for tar distillation. The size of the pits varied, with small ones holding from 1–1.2 m3 up to 60–70 m3 of wood (Fig. 7, 8). The pits had a diameter of a dozen or so meters and a depth of about 1.5 m in the central part. In technologically advanced tar furnaces, about 365–402 kg of tar was obtained from a single fathom of wood, while the amounts were much lower in the most primitive forms (obtaining tar in pits) (Broda 1959). At the beginning of the 15th century, ash was floated by merchants from Mazovia (Zakroczym, Wąsosz, Łomża, Ostrołęka, Różan, Maków, Świedziebnia). There are no records of transport of thermal wood processing products down the Vistula river from other parts of Poland (Hirsch 1858; Kutrzeba 1922; Sattler 1887). Prior to the intensive exploitation of coal and lignite deposits in Central Europe in the 19th century, the predominant high-energy fuel was charcoal extracted by dry distillation (Smil 2017). Grinders were used for firing charcoal. These were round piles of wood sifted with a layer of soil and forest litter, in which the energy raw material was combusted. The diameter of grinders ranged from a few meters to tens of meters. The distribution of relict sites of charcoal production (relict charcoal hearths, RCH) was irregular (Groenewoudt 2005; Schmidt et al. 2016). Some of the factors determining the location of charcoal production sites were the availability of wood substrate, local market demands, and the possibility of long-distance transport. The works of Schwedes (1983) and Schmidt et al. (2016) revealed several RCH locations in former oak, hornbeam, alder, and birch forests. The estimated density of RCH was 1 per 4.3–7.7 ha (Schmidt et al. 2016). Frommhold (2010) stated that each charcoal production site used wood from around 2 ha. These findings demonstrate that charcoal production is a potential factor modifying soil cover. Deforestation played an important role in initiating the remobilization of surface deposits and soil erosion (Jonczak et al. 2013; Rösler et al. 2012). One may presume that these were indirect effects of charcoal production. Removal of natural forest vegetation (sometimes multiple times in the same site) led to the succession and development of secondary, seminatural or unnatural plant communities.
Carrari et al. (2017) reported that the environmental conditions at charcoal production sites favor plant succession due to the availability of light and nutrients. However, in long term, the conditions become unfavorable due to changes in soil and rapid leaching of labile forms of nutrients. Augusto et al. (2002) showed that any modification in the composition of forest species can potentially alter the properties of associated soils. Soil cover of the sites affected by historical charcoal production forms a mosaic system dominated by seminatural soils with patches of strongly modified soils of RCHs. The RCH soils are characterized by specific features, of which the most typical ones are the presence of a single layer or layers of charcoal particles, ash, tar, and other products resulting from burning and pyrolysis (Aldeias et al. 2016; Knicker 2011; Raab et al. 2019). These products are highly resistant to decomposition and can persist in soils over millennia (Valese et al. 2014). The RCH soils also exhibit other properties: a) lower bulk density as compared to reference soils (Borchard et al. 2014; Criscuoli et al. 2014; Schneider et al. 2018); b) ability to strongly modify water regime, infiltration, and retention (Doerr et al. 2000); c) presence of charcoals causing changes in the thermal regime, including daily, seasonal, and annual temperatures; d) varying soil hydrophobicity (Schneider et al. 2018) and high proportion of soil organic matter due to charring and site preparation (Hirsch et al. 2018; Knicker 2011; Mataix-Solera et al. 2011); e) ability to influence soil pH (Hardy et al., 2016); f) higher sorption capacity as compared to the reference soils (Mastrolonardo et al. 2018); g) ability of thermal processing causing changes in the biogeochemical cycles of chemical elements, including their content, forms, mobility, and bioavailability (Hirsch et al. 2017; Mastrolonardo et al. 2018); and h) enrichment with other nutrients such as K, Ca, Mg, Na, Mn, and Zn (Mastrolonardo et al. 2018).
The impact of “charcoal hearths” on forest ecosystems ought to be considered in two aspects. The first facet of deforestation is related to the clearing of forest stands and their direct effect on the processes of landscape opening, followed by vegetation succession and its consequences (Słowiński et al. 2022). The second aspect is directly linked to the products that were targeted. For example, if the target was charcoal, wood could come from different tree species, while if the desired product was potash, the wood that could go into the miller had to be species such as Fagus, Carpinus, or Pinus. Therefore, one can assume that the production of potash or, for example, tar or charcoal selectively influences and shapes the structure of vegetation in forest ecosystems (Słowiński et al. 2022). To a certain extent, the formation of new forest ecosystems can be viewed as a process affecting the species structure of the forest, which is dictated by the demand for products (Słowiński et al. 2022). These behaviors can be called the protoplast of forest management. It should be remembered that deforestation can modify the forest microclimate. The microclimatic effect of charcoal hearths was multiphase and changed with time. In the first phase, at the time of site selection for charcoal hearth, the trees in a small area were completely cleared. The formation of a mid-forest clearing resulted in sudden changes in microclimatic conditions at that place, as well as in the surrounding edge of the forest, making them more sensitive to macroclimatic conditions (De Frenne et al. 2021). Compared to the forest interior, forest gaps are exposed to higher amounts of solar radiation and precipitation (due to lower interception) reaching the ground. These effects increase with the size of gaps but vary within the mid-forest clearing. The differences are especially large in dense coniferous and mixed forests (Chen et al. 1995). Deciduous forests experience greater seasonal fluctuations. Microclimate differences are determined by the diameter of the gap and its position relative to the sun, the height and structure of the surrounding forest, as well as the climate, season, and weather patterns (Abd Latif and Blackburn 2010; Chojnacka-Ożga et al. 2020; Geiger et al. 1995; Słowińska et al. 2022). The study on global buffering of temperatures under forest canopy by De Frenne et al. (2019) showed that the mean and maximum understory temperatures were, on average, lower than the macroclimate mean temperatures by 1.7 ± 0.3°C and 4.1 ± 0.5°C, respectively. On the other hand, the minimum temperatures of the forest understory were 1.1 ± 0.2°C warmer compared to mean temperatures outside the forest. These values may differ based on the forest gap and stands, but the direction of these averaged differences should be the same. However, at the time of charcoal hearths functioning, the gaps could be characterized by much higher air and soil temperatures and therefore reduced soil moisture and air humidity. After the charcoal kilns stop functioning, microclimatic differences with the surrounding forest gradually reduce as a result of plant succession. However, the high proportion of carbonaceous material remaining in the soil after burnout reduces the heat capacity of soil, causing greater thermal fluctuations compared to ambient soil plots (Schneider et al. 2019).
5.4. Names associated with honey harvesting
Foreigners visiting Poland in modern times were enthralled by the state of the native environment, pointing to the quality and abundance of honey obtained from the forests of Prussia, Mazovia, Podlasie, Ruthenia, and the Grand Duchy of Lithuania (Żukowski 1965). These claims were supported by the geographical distribution of the names associated with honey production from beehives (Fig. 9).
According to the available literature, beekeepers (especially during the Middle Ages and Early Modern period, i.e., before the 17th century) were primarily engaged in agriculture, while beekeeping was a secondary activity. They formed unified communities that were subordinated to the so-called honey harvesting law (Borkiewicz-Celińska 1974). The accounting unit was the honey forest, covering approximately 60 pine (less frequently spruce) trunks, forming a strongly distinctive landscape layer (Samojlik et al. 2020). Historical research data show that trunk distribution within individual forests was determined by the availability of suitable trees on which a beehive and local site conditions were established (Niklasson et al. 2010; Żukowski 1965). Often, trees located on riverside meadows, mid-forest clearings, or in ravines were chosen for beehives (Kielak 2004). A single hive yielded about 10 kg of honey per season. Individual apiary could be located between 8 and even 12 km from the beekeepers’ residence. Additionally, it is known that beekeepers earned their living from other activities such as hunting, fishing, trading, and timber floating. Because of their work, beekeepers enjoyed considerable freedom—they were permitted to hunt birds and small forest animals, and occasionally to chop wood from the forest for their own needs. The activity of beekeepers, which involved the frequent use of fire inside larger forest complexes, left clear traces. They regularly burned the lower layers of the forest to improve the honey yield of the plants around the beehives (Niklasson et al.2010).