Introduction

From the late Middle Ages until the end of the nineteenth century, the northwest coast of Portugal was severely affected by drift sands, which even led to the disappearance of some villages and forced the population to suffer several losses, or in even more dramatic cases, to migrate (Guerra 1899; Abreu 1987; Cunha et al. 1995). Along the northern European Atlantic coast, the most effective response to the drift sands that threatened the survival of many coastal communities was the reforestation of coastal areas, starting from the end of the seventeenth century, but especially in the eighteenth and nineteenth centuries (Joanaz de Melo 2017b, 20192023; Trápaga Monchet et al. 2023).

Pine trees, marram grass, and other plants have effectively fixed and stabilized dunes throughout Europe. Their use and management marked not only the landscape but also the scientific literature on forests, influencing intellectuals and forestry engineers who sought to apply their theoretical and empirical knowledge of these plants and dune dynamics to their countries in order to stabilize drift sands that tormented entire populations all along the European coastline (i. e. Silva 1815; Trápaga Monchet et al. 2023).

Throughout Portugal, from the middle of the eighteenth century, the “problematic” supply of forest products is documented. The significant population growth increased the need for more common products, such as firewood and charcoal. At the same time, the process of commons privatization accelerated it, which led to speculation on forest products and the respective afforestation. The 1755 earthquake and the reconstruction of Lisbon, or the series of cold and dry and bad agricultural years, had their importance on a regional scale. Prices increased in the Northwest of Portugal, the country's most wooded and populated area. All along the coast, shipyards needed to find fine wood and sources of supply were sought in Northern Europe, Sweden, Prussia, and Russia. However, several attempts at forest regeneration have also been documented, both in coastal areas and on the banks of the Tagus River (Joanaz de Melo 2017b, 2019, 2020a, 2023).

On the coastline, the cultivated areas alternated with moorland, heath, and pine forests. The pinewood area was very discontinuous, with greater incidence in the Leiria region. Nevertheless, there were then maritime pine plantations encouraged in order to block the advance of coastal dunes in the agricultural areas of the interior (Devy-Vareta and Monteiro Alves 2007; Trápaga Monchet 20172023; Joanaz de Melo 2020b, 2023).

In the Northwest, the State and forestry engineers only intervened more directly in coastal reforestation in the nineteenth century (Mendia 1881). However, the Portuguese State was present and aware of the problems of the coastal areas through the indirect intervention of the manorial houses linked to the Crown and the municipal officials. The Central State imposed laws and orders of afforestation and forest preservation. Through indirect intervention by the House of Bragança and its local officials (reigning house) or by the House of Infantado (manor house of the monarch's second sons) was the application of strategies similar to those of the royal forests on the coast between the Minho and Ave rivers, observed since the end of seventeenth century. In this text, in addition to the public initiative of planning coastal areas, we propose the historical analysis of how private organisations, particularly monastic institutions, sought to manage the coast, promoting reforestation and promote the economy. Although these various institutions were aware of and intervened in coastline, the planning and management of the forests in coastal areas were mainly responsible for local private civil and religious institutions or individuals due to their geographical proximity. In this article, based on historical documentation, we propose to analyse the reforestation initiatives of coastal areas promoted by monastic institutions and how these actions were implemented and managed between the diffusion of forestry knowledge on the fixation of dune areas and the ecological and economic constraints of the intervened areas.

These implemented interventions were only one of many examples throughout the portuguese and European coastline of the afforestation of dune areas to protect bars, contain silting, and prevent the advance of sediments over cultivated areas that occurred at the end of the eighteenth century. In the portuguese case, it is one of the cases since the mid-eighteenth century (Joanaz de Melo 2019, 2020b) that, independently of its organization and its mindset about land and resource exploitation, inaugurates the decisive start of dune afforestation, which only takes place definitively at the second half of the nineteenth century (Silva 1815; Devy-Vareta and Monteiro Alves 2007; Joanaz de Melo 2017a; Soromenho-Marques and García-Pereda 2018). It also aims to demonstrate that, apart from the State, as mentioned, private institutions, at the end of the eighteenth century, also desired, as they faced identical issues with drift sands, the same afforestation of the dunes.

In addition to the ecological and spatial planning components of stabilizing dunes and avoiding loss of arable land, we must also consider that these initiatives were embedded in a context of agricultural and economic promotion that was influenced by the physiocrats' policies of the late 18th and early nineteenth centuries, presenting the pine tree as profitable specie. Physiocratic ideas changed plantation policy and rebuilt a new forest (Devy-Vareta and Monteiro Alves 2007; Joanaz de Melo 2019, 2023). Monastic institutions with their libraries were privileged spaces for the reception of these ideas. In the second half of the eighteenth century, the Enlightenment tendencies pursued to reconcile rationalism and sensism, implying a new idea of reason, dynamic evolution, openness to experience, and regulation toward moral and scientific progress. Many of the monks who had the opportunity to receive higher education in Coimbra College were able to absorb the new rationalist Enlightenment thought in vogue and the new concepts that were circulating and that, from all over Europe, were arriving in Portugal, particularly in that city (Oliveira 2005; Soromenho-Marques and García-Pereda 2018).

Based on the proposed questions, the article is divided into five parts:

  1. 1.

    The study area's climate, seashore, hydrography, and geological evolution are characterized.

  2. 2.

    The historical sources, the details registered by each, and their production context are indicated.

  3. 3.

    The centenary importance of the pine tree in fixing dune areas and the experiences, knowledge, and selection of species more appropriate to the portuguese territory is analyzed.

  4. 4.

    The experiments promoted by monastic institutions at the end of the eighteenth century are interpreted according to the recognition of the territory, the experts involved, and the available resources and scientific knowledge.

  5. 5.

    It is equated if these actions had permanent results in fixing the dunes of North-western Portugal.

Although focusing more on the past than on the present or making any predictions of future coastal changes, this study will allow a comparison of how the north-western Portuguese coastal landscape has been remodelled and managed over two centuries, between management by local institutions in the eighteenth and nineteenth centuries, the profound and catastrophic impacts caused by tourism activities and infrastructures in the second half of the twentieth century and the implementation of coastal management plans by the Portuguese State (POOC) since 1993 (Granja 1990; Loureiro 2006; Cardoso 2007).

The study area (Figs. 1, 2 and 3)

Fig. 1
figure 1

Historical map of study area (Norton 1807). ©Portugal National Library, D-191-A

Fig. 2
figure 2

Rodanho — Amorosa dune sector (Viana do Castelo, August 2023)

Fig. 3
figure 3

© Atlas de Cartografia Histórica

Municipalities and parishes division in the NW coastline of Portugal in 1801

The study area borders Galicia (Spain) in the North and the Atlantic Ocean (Fig. 1). It presents a humid climate, with relatively high exposure to maritime winds, high annual precipitation (1200–2400 mm), mild summers (18-22ºC), and relatively low annual insolation (> 2500 h) (Moreno et al. 2016).

The coastline of north-western Portugal presents an NNW-SSE orientation from the border with Galicia at the mouth of the river Minho and 50 km to the north of the city of Póvoa de Varzim. The coast is marked by outcrops of igneous and metamorphic rocks that come into direct contact with the sea. The cliffs in this area are essentially low, with very few high cliffs. The coastline is composed of beach sand and rarely appears coarse material such as gravel or pebbles. The Esposende strip presents some morphological heterogeneity, with sandy beaches with low slopes predominating south of the Cávado estuary. In contrast, the pebble and mixed beaches (sand and pebbles) and relatively high slopes are more representative in the northern sector. On the coast of Esposende, the sands of the beaches are replaced by gravels that increase in length and volume yearly, while there is a migration of beaches (Alves 1996; Loureiro 2006; Gomes et al. 2002).

The littoral platform is a flattened surface that varies between the mouth of the Minho River and Âncora, 400 m wide to 10–30 m (33–98 ft) on the Apúlia coast (Granja 1990; Loureiro 2006; Araújo 2016). In addition to the accidents of geological character, several river mouths are also elements that contribute to an irregular coast outline. Along the seashore, the continental morphology is dominated by an almost continuous line of granitic rocks that extends from the northern side towards Spain. This granitic strip is only interrupted by the valleys of the rivers Minho, Âncora, Lima, Neiva, and Cávado. All of them have an ENE-WSW orientation. The hydrography is based on multiple small and medium hydrographic basins of low and average altitudes. In these fluvial courses, as a manifestation of the current transgressive trend, an intense silting up of the river mouths is verified, being frequently practiced in the most prominent rivers (Minho, Lima, and Cávado), the dredging of the bars and access channels (Alves 1996; Loureiro 2006) (Fig. 1).

An essential part of the study area is covered by aeolian sands of variable thickness, consisting of several patches and some of them relatively extensive. These patches include the dune areas Caminha-Moledo, Vila Praia de Âncora-Promontório da Gelfa—Montedor, Carreço, Darque-Castelo de Neiva (Fig. 2). These dune areas are parallel to the coastline, with several ridges, with variable heights between 8–12 m, sometimes 15 m and even 20 m (south bank of the Lima River—Rodanho Beach) (Fig. 2). In the south of the Neiva River, frontal dunes are evident between the mouth of this river, Belinho Beach, and Cepães (Alves 1996; Gomes et al. 2002). Given the location of these deposits, it is assumed that the recent evolution of the landscape, particularly during the Little Ice Age, led to the development of an extensive eolian dune cover, contributing to the preservation of previous formations. The alluvial sediments of more recent origin are located on the banks of the Lima River and the southern coastline, in Darque, Anha, and Chafé, where the most extensive dune ridges in the municipality of Viana do Castelo are located, of the unconsolidated type. These parabolic dunes have a longitudinal shape, are arranged parallel to the coastline (Fig. 2), and can be seen more than 3 km from the coastline at an altitude of up to 160 m (Faro de Anha climbing dunes) (Alves 1996; Carvalhido et al. 2014) (Fig. 1). In the south of the Cávado River, on the coast between Estela and Aver o Mar, the dunes reach 4 m (Cardoso 2007).

Proving the effects of the Little Ice Age is the archaeological and historical evidence of abandoned parishes of Santa Maria das Areias (Darque), São João de Ester (Chafé), Fão (Costa 1706–1712; Cardoso 1747; Guerra 1899; Abreu 1987; Granja 1990; Cunha et al. 1995; Capela 2003, 2005) and some local legends about the abandonment of the medieval parishes of Apúlia and Vila Mendo (Estela) (Costa 1706–1712; Cardoso 1747). These historical and archaeological data are also proven by the Optically Stimulated Luminescence (OSL) data obtained by Carvalhido et al. (2014). The historic units Ribeira de Anha and Galeão Sands have been dated to the late sixteenth century and the late eighteenth century; therefore, these layers are related to the climatic crisis of the Little Ice Age. Ribeira de Anha records, dated between 1590 and 1650, show us water availability typical of climatic conditions that immediately preceded the Maunder Minimum, relating to fluvial sedimentation on Ribeira de Anha. The Galeão sands record the Little Ice Age, relating mild and dry climatic conditions and reflecting intense dynamic wind activity during the Dalton Minimum (1780 – 1820) – between the beginning of the seventeenth century and the end of the nineteenth century – and which promoted sand deposits that covered coastal terraces located up to 160 m.

Little Ice Age also has been significant in terms of coastal regression. This climatic variation may have been responsible for a significant sea level decrease, reaching its lowest point around 1830 (Granja 1990; Loureiro 2006; Araújo et al. 2003). Some toponyms of cultivated land, such as "field under the sea slate" or fields that became cultivated in the "wet of the sea", are in the historical sources of the seventeenth and eighteenth centuries that document sea level regression.

After this period and still today, a sea level rise has been observed, which, with other causes, has led to severe coastal erosion phenomena (Granja 1990; Loureiro 2006; Araújo et al. 2003; Faria 2012) (Fig. 2). Currently, the coastal platform is used for agricultural, habitational, and touristic purposes, or when covered by pine forests, with a mix of maritime pine (Pinus pinaster) and stone pine (Pinus pinae). The density of these green areas has created some difficulty in identifying the dune forms (Lopes 1987; Alves 1996), although nowadays, the intensive felling of pine trees and acacia melanoxylon to increase habitational and industrial area and road construction has revealed the large dune complex.

Historical sources and methodology

Historical sources are scarce and fragmented for studying drift sands, especially related to earlier periods. However, their information provides crucial data allowing societal changes related to geological events, such as drift sands and landscape instability (De Keyzer and Bateman 2018). Like Bavel and Curtis (2016), it is argued that a historical approach allows us to deepen our knowledge about distinct and divergent social structures administered by different institutions, whether religious or civil, offering the possibility of comparing not only regions but also chronologies in order to analyze how the coastal landscape has changed. This perspective also allows us to explicitly recognize the impact of historical trajectory on contemporary coastal development, namely at the level of dune dynamics.

This text is based on historical documents such as geographic and historical descriptions, economic memoirs, and local institutions' historical documentation, namely São Romão de Neiva monastery (Viana do Castelo) and São Martinho de Tibães monastery (Braga). As will be listed below, the choice of monastic institutions is due to the active and constant concern these institutions had with their forests and because, in the second half of the eighteenth century, they were among the institutions present in Northwest Portugal that paid the most attention to the forestation of the coast. The documentation of these religious institutions is kept at the Braga District Archive (BDA) and, taking into account the indications of the sources used by Aurélio de Oliveira (1979; 1997), Ramos (1977) and Marques (2011), preference was given to the analysis of the activity reports of the monasteries (Estados) which report the internal functioning, material revenues, works in the monastery (namely plantations) and as well, other notes of interest concerning community life. The expenditure books were also consulted in search of evidence of the purchase of pine seeds used in the afforestation of coastal areas and several series of ongoing conflicts and legal proceedings in which these two monasteries were involved, namely those aimed at the reiteration of the rights of property on common lands located by the sea and wooded with pine trees. In this research, we also used documents such as contract books—compendiums that gather the list of contracts made between the monastery and its peasants to make their properties profitable from an economic point of view—being possible to verify and map the existing vegetation on the leased (trees, bushes, heather or absence of vegetation), the type of soil (sandy, clay, marshland), the proximity to the sea and the existence of dunes and whether or not they were cultivated. These management instruments were produced in response to the need for control and inspection and to assess the application of the rule of Saint Benedict and economic promotion. The inventories of 1834, the date of closure of these male Benedictine monasteries, were also consulted to understand the scientific influences (library contents) of the monks who conceived these afforestation projects and partially mentioned by Giurgevich and Leitão (2016).

Crossing historical sources, we will first analyse forest management actions envisioned by monastic institutions, i.e., what forest species were used and whether their application had a theoretical or empirical origin. We will also analyse how communities were involved in these initiatives and whether they became a cooperating element or whether they consciously or unconsciously jeopardized them. Second, it will be analyzed whether these initiatives successfully made communities in north-western Portugal less vulnerable to drift sands and whether they served as models for coastal reforestation in other regions or for later chronologies.

Pine tree – an ancient agent in coastal forestation

Drifting sands along Europe have occurred from the UK (Bateman and Godby 2004; Charman 2010; De Keyzer and Bateman 2018) on the French Atlantic coast (Clarke and Rendell 2006; Guillemet 2000; Charpentier 2013; Caillosse 2015; Lageat et al. 2019), in the Netherlands (Castel 1991; Jungerius and Riksen 2010), in Belgium (De Keyzer 2014, 2016), in Denmark (Clemmensen et al. 2001, 2007, 2009), Norway (Tørum and Gudmestad 2013) and Portugal (Clarke and Rendell 2006, 2011; Costas et al. 2012; Lopes 2019; Tudor et al. 2021). In coastal and inland sandy areas, uncontrolled sands quickly destroy the most vulnerable areas of intensive cultivation, usually located near the centres of localities, weakening the ecosystem balance with devastating results on the landscape and the daily lives of populations (De Keyzer 2016).

The landscape instability caused by drift sands seems to be attributed to climate, the pressure caused by population increase, agricultural overexploitation, increasing mobility, and road use (Castel 1991; Cordova 2007; Derese et al. 2010; Heidinga 2010; Koster 2010; Rosen 2011; Fan et al. 2016; Henry et al. 2017; Pierik et al. 2018). These events occurred already on the European coast with known repercussions for the populations of the late Middle Ages throughout the tenth and eleventh centuries, with the sand covering population cores, fields, and pastures (De Keyzer 2016; Pierik et al. 2018). However, as mentioned above, the fifteenth and sixteenth centuries devastated Europe, burying rural settlements.

Over time, it has also been shown that communities could install and maintain dune erosion mitigation measures, namely afforestation, and even punish those who cut or destroy these vegetation defences (De Keyzer 2016; De Keyzer and Bateman 2018). de Keyzer (2014, 2016) mentions that the communities of Campine (Belgium) learned from the first irreversible effects of the early Middle Ages to install siding and wooden fences around virtually every piece of arable land. Near the common wastelands, they erected hardy herbaceous bushes, heather, and scrub and strategically planted trees, bushes, and hedges on the fragile dunes and throughout the community.

A similar scenario was observed in northwest Portugal. In the thirteenth century, King Dinis ordered planting a pine forest near the mouth of the Minho River to stop the advance of sands over agricultural land, which successively affected the populations of Moledo and Cristelo throughout the Middle Ages (Bento et al. 2009). At the beginning of the Early Modern Age, the inhabitants of Apúlia put up coverings and hedges to defend themselves from the sands that stubbornly sterilized their fields. The individuals were penalized if they did not participate in these community activities or if they cut their bushes (Cardoso 1747; Soares 1986). These same aspects are also verified further north, in Afife, at the end of the nineteenth century and the beginning of the twentieth century (Faria 1987).

Some coastal dunes were stabilized by vegetation, particularly by marram grass, beach-couch grass, and pine trees, during the past two centuries (Steers 1973; Bird 2001). The hedge planting further complemented the dune afforestation, which grew more quickly (Silva 1815; Joanaz de Melo 2017a).

A few variations in the plant species act as colonizers and foredune builders. Marram grass is the most vigorous of the dune-building plants because it grows up rapidly through accreting blown sands. All these plants are characterized by their high salt tolerance and elaborate root systems, and therefore, the effect of these plants on dune stability is limitless (Goldsmith 1978; Bird 2001; Steenwoerd and Ouden 2010). The pine also proved to be an excellent option in forestation due to its economic viability, both for its ecological plasticity and low demands on soil, but also because it represented a good energy source for the owner, having multiple markets that adapt to the different exploitation phases. The forestation with these species was not only an opportunity to transform the territory of the dunes but was also part of a functionalist vision of it. Besides protecting the people and their territory from the sand, the pine forests were seen as an opportunity for economic development. The wood and leaves served the population and animals, the wood and resin transforming industries (Devy-Vareta 1999).

In the sixteenth-seventeenth centuries, Pinus sylvestris was introduced to the Netherlands for dune planting and proved very successful in rapidly reducing the areas of drift sands in north-western Europe (Steenwoerd and Ouden 2010). Significant afforestation of these fragile areas took place mainly in the late eighteenth century, especially throughout the nineteenth century and the first decades of the twentieth century (Fanta and Siepel 2010; Koster 2010; Tørum and Gudmestad 2013). The icon of coastal afforestation in the late eighteenth century was the Pilat dune (SW France), a vast mass of sand moving from the shore south of the Bassin d'Arcachon and spilling inland over the Landes pine forests (Tassin 1801–1802; Boye 1986; Vieira 1995; Freitas 2004).

Since the seventeenth century, there have been recommendations for reforestation throughout the Portuguese legislation that protects woods and afforestation in Portugal. Both the Crown, in the royal forests, and private institutions, throughout the Early Modern Age, demonstrated awareness and constant action of protection through legislation and orders on access, use, and control of forest resources, but also developed reforestation actions, namely of some monocultures such as pine tree or cork oak (Devy-Vareta 1986; Joanaz de Melo 2017b, 2019, 2023; Trápaga Monchet et al. 2023). The primary concern in afforestation in the nineteenth century was the forestation of the extensive coastal dunes, as well as the mountainous land subject to the action of torrents. The scale and cost of the work required the State to plant the dunes on the seashore, an inaccessible task to private citizens.Footnote 1 For this purpose, the State had administrative services, which were reformulated several times throughout the nineteenth century (Radich 1996).

Portugal's most common pine trees were the maritime pine and the stone pine. Besides these species, Pinus sylvestris is also documented by the end of the eighteenth century. Throughout the nineteenth century, other species, such as the Aleppo pine and the Corsican pine, were also introduced (Radich 1996).

The processes of creation and exploitation of the coastal pine forests in Portugal were described in the first half of the nineteenth century by Silva (1815) and his disciples Brotero (1827) and Varnhagen (1836), in texts partially contradictory to each other, especially as regards the timing of the season for collecting and processing the pinecones used for sowing, the need to prepare the land for sowing and the planting of creeping species or their uprooting (Radich 1996; Soromenho-Marques and García-Pereda 2018).

Since the eighteenth century, the afforestation of dunes has been recommended. The attempts to plant trees on the coastal dunes were continuous from the 1750s until the early nineteenth century, only stopped by French invasions and the royal family's escape to Brazil (Martins 2014; Joanaz de Melo 2019, 2023). At that chronology, an attempt was made to compile a first register of the national pine forests, or some unsuccessful attempts were made to plant trees on the dunes of Leiria, Aveiro, and Ovar. José Bonifácio de Andrada e Silva (1763–1838), a naturalist and mineralogist in the Enlightenment tradition, pioneered the colonization of the dunes' forests. For José Bonifácio (Silva 1815), the greatest enemy of the Portuguese coast was the sand blowing caused by the stormiest winds, the Northwest wind, which prevailed during the dry season, the Summer, when the sands were looser and more movable. The action of the wind, along with the maritime currents (north to south), formed sandpits at the mouths of the rivers. Gifted with a government grant, he travelled and studied in Europe for ten years. He returned to Portugal in 1800 and began cultivating pine trees on the dunes of Lavos, south of the mouth of the Mondego River, encouraged by the royal charter of 1802. The work only began in 1805 and was soon delayed by the French invasions. During these journeys, he travelled mainly through France and Germany and had contact with the Forest Chief of Brandenburg and the afforestation of the sandbanks of Gascony and Netherlands (Mendes and Fernandes 2007; Soromenho-Marques and García-Pereda 2018).

His memoirs (Silva 1815) reveal an extreme knowledge of the agronomic classics of antiquity. However, he also cites the best naturalists of his time, such as Friedrich August Ludwig von Burgsdorf, Jean-Antoine Chaptal in enology, and Duhamel de Monceau in forestry. For the first time in Lavos and the entire Iberian Peninsula, he applied the forestry techniques developed in Germany in the eighteenth century. José Bonifácio may be considered in the forestry universe as the introducer of the scientific and methodological approach to Portuguese forestation (Soromenho-Marques and García-Pereda 2018; Teixeira 2016).

After José Bonifácio, only in the 1880s was an explicit and detailed description of the management of pinewoods (more favourable climates and soils, seed quality, sowing processes and seasons, and fire prevention) (Radich 1996). This attention to dune areas only appeared around 1860 following several storms and floods on the coast, whose news of their disastrous impacts reached Parliament and, only in 1880, when there was already a group of forestry engineers trained in Portugal with intensive fieldwork and in-depth knowledge of forestry and hydraulics, was created the structures to stabilize of the coastline (Devy-Vareta 1993; Radich 1996; Joanaz de Melo 2017a).

Although pine forests only became widely established nationally in the nineteenth century, the end of the eighteenth century was already marked by some forestation projects, namely the one on which this text is based. Nevertheless, as Trápaga Monchet’s (2019, 2023) work on the royal forests of the seventeenth century has shown, the preference for pine monoculture was already evident a century before. In Portugal, contemporaneous with the projects instigated by the Benedictine monasteries (Oliveira 1979, 1997) or other settlements instigated by some intellectuals (Cruz 1970; Devy-Vareta 1993), in the central coast, in 1791, there was an attempt at the afforestation of around 100 ha of dunes on Vieira beach. In 1805, Silva (1815), in Lavos, directed forestation work on the dunes but was interrupted by the invasions of the Napoleonic troops. However, from the mid-nineteenth century onwards, the dune afforestation projects multiplied and intensified along Portugal's Northwest and central coast. Since 1880 it has also extended to the coast south of the Tagus and the Algarve (Radich 1996). At the end of the nineteenth century, and despite all the coastal afforestation plans since 1868, about 37,000 hectares of the Portuguese coast were still deserted (Teixeira 2016).

Experiences in the Northwest coastline of Portugal in the eighteenth century

The northwest coast of Portugal allows us to observe several contexts for coastal afforestation given the great entanglement of institutions present that controlled access to water resources, coastal areas, arable land, and forest, organized in local and regional bodies, depending on the geographical proximity to the administered location. Although decision-making processes were sometimes very localized (i.e., organized by parish or groups of parishes), there was generally a coherence of decision-making at the municipal, regional, and even national levels.Footnote 2

The monasteries were owned by private individuals who owned large, wooded areas, looking forward to the best management of their heritage since the Middle Ages of their heritage (Oliveira 1979; Maduro 2010). The monasteries regularly implemented forestry plantations in the areas they directly managed. The first forest inventories in the country were undertaken by the great monasteries, such as that of Alcobaça in 1530, anticipating or contemporaneous with the royal institutions' initiatives to promote the reforestation of coastal pine forests degraded by fires and logging (Devy-Vareta and Monteiro Alves 2007). Throughout the seventeenth century, in the extensive territory of the Tibães abbey (Braga), plantations of oaks, cork oaks, and chestnut trees continued. In the following century, the abbey added more willows and developed the promotion of pine forests or olive trees (Oliveira 1979), which will be discussed here.

At the beginning of the nineteenth century, the forest situation was considered catastrophic (Silva 1815), although there were no statistical elements to prove it (Joanaz de Melo 2019). Many parts of the peasant forest, integrated into local agrosystems, managed and exploited for current uses, were disregarded and incorporated into scrubland areas. Much of this unsavoury characterization arises from the concept of a forest for producing hardwoods used in naval construction. This scenario of supposedly massive deforestation (Reboredo and Pais 2012, 2014) has been contradicted in recent years, thanks to the work of Cristina Joanaz de Melo and Koldo Trapága Monchet (Joanaz de Melo 2017b, 2019, 2023; Trápaga Monchet 2017, 2019, 2023; Trápaga Monchet et al. 2023) which have shown that throughout the 16th to eighteenth centuries, in the forests belonging to the Crown, there was constant protection and actions of reforestation and extension of the life of the trees. The legislation only placed the focus of forest destruction on the lower classes for forest crimes, hiding the Crown's objective of legitimising the extraction of forest trees on other manorial lands, as well as demonstrating that shipbuilding was no more destructive than other economic activities and, in some cases, even helped to implement sustainable forest management to ensure its survival.

In the 1800s, the forest area comprised a much more heterogeneous mosaic of species than today. There was a greater variety of Mediterranean essences in northern Portugal: cork oaks and maritime pines are mentioned alongside oak and chestnut trees. During the first half of the nineteenth century, the forest suffered the impact of the turbulences linked to the liberal revolutions, in which many lands changed owners under the effect of the land changes that characterized this period, as is the case of the territory under study. New exploitation and forest management practices will favour wood cutting and new plantations, namely maritime pine, made profitable by the increased demand (Devy-Vareta and Monteiro Alves 2007; Joanaz de Melo 2019, 2023). Link and Hoffmansegg (1808) described the Northwest with gardened woods of oaks, cork oaks, and chestnuts. Pine forests marked the coast. They point out the Camarido National Forest, an extensive pine and cork oak tree forest. The Viscount of Balsemão also shows the abundance of pine forests in the coastal areas and along the Minho River (Porto Public Municipal Library [PPML], Ms. 294).

There is a contrast in the Minho Forest between what were the forests of the lands administered by the monasteries and those of other landowners administered. In addition to these woods being indispensable for the monasteries' agricultural activities and constructions, forest products were commercialized, constituting an essential source of income for the monasteries (Devy-Vareta 1993). All these physiocratic practices were deep-rooted in the monks, and the Congregation of Saint Benedict played a relevant role in their diffusion. These ideas were no longer new when they spread in the eighteenth century (Oliveira 1997). In order to dynamize the economy by fostering production, the Benedictine monasteries stimulated their agriculture, cultivating land until then unploughed, diversifying or intensifying profitable farming in the light of the physiocratic teachings that were so dear to the economists of the Royal Academy of Sciences. The measures were inspired by theory but responded to the specific needs of the Benedictines, who needed income from cereal, wine, olive oil, and other fruits to pay taxes and meet other needs (Ramos 1977). The importance of institutions in protecting societies from hazards and encouraging or hindering recovery after an event is now recognized. However, it is necessary to consider the positions of these institutions and contextualize them in space and time, considering that specific measures were exclusively oriented towards the solution of disasters. Likewise, the presence of different social groups or individuals who control institutions' directions, actions, functioning, and participation should also be evaluated (Aldrich and Meyer 2015; Bavel and Curtis 2016). Physiocratic policies and liberal ideas marked the second half of the eighteenth century. The issues of the questionable lack of woody material, the issue of scrub, and the afforestation of the commons and wastelands dominated the socio-economic life of monasteries, manor houses, municipalities, and populations. All these actors were involved in the issue of forest promotion and management (Devy-Vareta 2002).

In northern Portugal, suggestions for planting trees in the monasteries' leases have been known since the thirteenth century. Various descriptions of the period and some studies (Maduro 2010) demonstrate that the religious orders, namely the Benedictine monastic houses (Oliveira 1979, 1997), took the best care of their goods, prolonging the ancient policies of plantations and regulation of cuttings. In all Benedictine houses in Northwest Portugal, plantations of olive trees, cork oaks, and chestnut trees were made throughout the seventeenth and eighteenth centuries. To these species, we can add the pine tree, which was vigorously planted during the 1720s, and in the second half of the eighteenth century. Also, during this chronology, the Benedictine monasteries and the Congregation of São Bento de Portugal strengthened their vigilance over their lands when the cutting down of trees and scrub became more frequent (Ramos 1977; Oliveira 1979; Devy-Vareta 1993; Marques 2011).

At the end of the eighteenth century, pinewoods were abundant in coastal municipalities but were composed of small-sized pine trees. They were found along the Minho River, namely in Caminha. In Esposende, practically the only existing species was the pine tree, which spontaneously regenerated when the pine seed fell with the wind, supplying the laziness of the landowners. In the municipalities of Viana and Barcelos, the pine trees were excessive, and the land that could be planted with trees provided charcoal. However, they were in a bad state due to the lack of cleaning and planning and the damage caused by fire and animals. Only the monastery woods escaped this devastating scenario (Cruz 1970; Devy-Vareta 1993).

By the end of the eighteenth century, the dunes and their instability defined the coastal landscape of Northwest Portugal (Lobo 1815; Link and Hoffmansegg 1808; Cruz 1970). The silting up of agricultural fields was the effect of drifting sand most frequently mentioned in the documentation on the communities of north-western Portugal (Capela 2003, 2005). At the end of the seventeenth century — early eighteenth century, King Pedro II ordered the plantation of a continuous pine forest between the Lima and Ave rivers (BDA, São Martinho de Tibães, Book 31), a contemporary measure of some Benedictine monasteries (BDA, Congregação de São Bento de Portugal, Book 162) and some individuals (Barcelos Municipal Archive, 4200–228). Nevertheless, in the second half of the eighteenth century, the initiatives of coastal forestation intensified. The Camarido National Forest was, in 1762, sown with pine seeds to defend the parishes of Moledo and Cristelo (Caminha) from sand, while cutting trees, bushes, and grazing cattle was forbidden (National Archive Torre do Tombo [NATT], Casa do Infantado, Book 1141). This forest is still mentioned in 1758 as the only means of protecting the inhabitants from the sands brought by the wind (Capela 2005). Furthermore, it is in this context of economic development and of preventing further loss of arable land that the Congregation of Sant Benedict of Portugal, between 1750 and 1780, in all its monasteries and, later, specifically, in the monasteries of São Romão de Neiva (Fig. 4), between the end of 1780 and the end of 1790, will develop reforestation projects in the parishes of Anha-Castelo de Neiva (Viana do Castelo) and in São Martinho de Tibães, in Estela (Póvoa de Varzim), respectively, by the hand of the "agronomist" monk João Baptista do Desterro.

Fig. 4
figure 4

São Romão de Neiva monastery (Viana do Castelo, April 2022)

As for reforestation promoted by the Benedictines, a pilot project was launched in the late 1780s and early 1790s in the coastal region between the Lima and Neiva rivers, one of the most problematic areas of drifting sand, where entire communities had disappeared by the end of the Middle Ages, as already mentioned. Of all the Benedictine houses historiographed by Friar São Tomás (1651), São Romão de Neiva seems to be, in fact, the most economically affected and vulnerable to coastal transformations, in the mid-seventeenth century, either as a result of the concentration of land in the hands of the comendataries and their mismanagement until 1630 or because the sanded agricultural fields in São João de Ester (Figs. 5 and 6), the Monastery of São Romão de Neiva held only one-third of all the income it used to generate until the end of the sixteenth century.

Fig. 5
figure 5

São João de Ester dunes and pine trees (Chafé, Viana do Castelo)

Fig. 6
figure 6

São João de Ester dunes and pine trees (Chafé, Viana do Castelo)

Throughout the eighteenth century, the pine tree became a species constantly planted on the São Romão de Neiva Monastery grounds (Figs. 5 and 6). The first indications to reform the pine forests dated from 1719 and that they would not be extinguished or missed until the 1820s. Also, from 1731 until the extinction of the monastery in 1834, it was forbidden to cut the pine trees by the trunk, except for those used in the monastery's works or, in case they were already old, they could be used to make bread. If they were rotten, they could be given to the poorest. Moreover, it is in the wake of these regulations that at the latter date and lasting until the end of the eighteenth century. The indication was made that each year a bushel of pine kernels should be sown in order to compensate for the deforestation that the monastery was experiencing at the time (BDA, São Romão de Neiva, Book 172 and 175). This recommendation was general to all the monasteries of the Congregation of São Bento of Portugal (BDA, Congregação de São Bento of Portugal, Book 162). In 1768, although the pine species to be planted was not defined before, it was stated that preference should be given to the Flanders pine (BDA, São Romão de Neiva, Book 174). The "Flanders pine" is one of the vernacular qualifiers of Pinus sylvestris (Fernandes et al. 2015). These historical data, as well as others scattered in local documentation, thus demonstrate, once again, that in the eighteenth century, Portugal was not completely deforested and that several public and private institutions guided the management of green areas in a way that today we could consider sustainable (Trápaga Monchet et al. 2023; Joanaz de Melo 2017b, 2019, 2020a, b, 2023).

For the plantation of the pine tree, since 1750, the values and quantity of purchased pinewood have been noted in the expenditure books. The purchase of pine nuts for deliberate planting in Portugal was evident in the royal forests as early as the first decades of the seventeenth century, during the Iberian Monarchy, when around 60 bushels were imported from the Sierra de Cuenca (Madrid, Spain) to the Tagus valley and Leiria (Trápaga Monchet 2019, 2023). However, the amount purchased was much lower than that recommended by the Congregation of São Bento of Portugal. Generally, the amount varies between half a bushel, and the maximum bought is one bushel. The price of pine seeds varies between 205 and 1000 réis per bushel (BDA, São Romão de Neiva, 116, 117, and 118). After 1771, there are no more references to the purchase of pinion. The last reference to Flanders pine seeds was made in 1778. The Congregation of Saint Benedict of Portugal indicates that, if possible, afforestation with pine kernels should also be done with ones from old pine trees (BDA, Congregação de São Bento de Portugal, Book 165).

We presume there may also have been spontaneous planting of pine trees since pine nuts easily fell from the pinecones, sometimes also being a source of food for the sheep (BDA, São Romão de Neiva, Book 173).

It is in this context of already insistent afforestation with pine trees that, at the end of the 1780s, the monk João Baptista do Desterro (1760–1810) arrived at the São Romão Monastery and started the afforestation and fixing of the dunes of the extinct parish of São João de Ester (Figs. 5, 6 and 7), submerged by sand between the end of the fifteenth century (Guerra 1899). He held the position of receiver monk for many years. In this position, he promoted the plowing of land in the various parishes where the monastery ruled. As the master builder, a primary concern was water management and supply. In the last three years of his life, he returned as abbot and where he died (PPML, Ms.1339).

Fig. 7
figure 7

São João de Ester and Lordelo reforestation by São Romão Monastery and Braganza Ducal House (1789–1805)

Friar João Baptista do Desterro (17/02/1760—23/06/1810), was born João Baptista da Silva in Ponte de Lima. At 21, he entered the monastic life, in the Benedictine order, in Santo Tirso Monastery. As an ordinance, he lived in several of the houses of the St. Benedict Congregation, passing in 1782 in the monastery of Refojos de Basto as a chorister; in 1783, he studied theology in Travanca and 1786, he assumed the role of the preacher in the mother house of the Congregation, in Tibães. Then, finally, he took the position of Rent Receiver in São Romão de Neiva for over a decade. In 1799 he was invited by Manuel de Santa Rita, who oversaw the Congregation, to manage the lands of Estela. Although he did not leave any writings about the forestations he directed ("he was very industrious)" (PPML, Ms. 1339), throughout his life, he had the opportunity to read and get to know various national and international authors in the rich libraries of the Benedictine monasteries, especially in Tibães library. It was common to find books by Montesquieu, Verney, Mabillon, Vandelli, other authors, the Encyclopaedia, and national and foreign periodicals. Even in some of the monasteries, the possession of forbidden books was authorized (Oliveira 2005). Thus, throughout his journey, Friar João Baptista do Desterro had the opportunity to read agricultural courses, treatises on hydraulics, works on physics and mathematics by French and German authors, and the recent works published by the Lisbon Academy of Sciences on astronomy, economics and agronomy (NATT, Ministério das Finanças, Convento de São Miguel de Refojos de Basto, cx. 2247; NATT, Ministério das Finanças, Mosteiro de São Martinho de Tibães, cx. 2256). In the monastery of São Romão de Neiva, he had contact with remarkable works of the Iberian Enlightenment, such as those produced by Benito Jeronimo Feijoo, with Pascal's works on mathematics or Bluteau's manuals on agriculture and mulberry production from the seventeenth century. Already during his presence as abbot of the monastery, he may have been responsible for the purchase of Flora Lusitanica, by Felix Avelar Brotero, printed in 1804 (NATT, Ministério das Finanças, Convento de São Romão de Neiva, cx. 2240).

Its intervention seems to have been significant since the land lost since the sixteenth century for the sands was regained, with no further losses and a multiplication of land contracts in the sandy areas, which yielded various types of cereals (BDA, São Romão de Neiva, Book 184). On the other hand, although Dalton's Minimum had a significant dune impact in the areas near the monastery and the pine forest, in the territory between São João de Ester and the Lordelo bouquets (Carvalhido et al. 2014), the historical sources do not seem to detect any situation of instability. On the opposite, there was an increase in the production of cereal and wine and even a struggle for access to these common lands on the part of the House of Bragança and the inhabitants, causing conflicts with the monastery. Between the end of the eighteenth century and the beginning of the nineteenth century, in that same territory and the neighbors', the House of Bragança devised a plan to forest the sands with pines, shrubs, and sand-couch grass to avoid those same drift sands (Figs. 5, 6 and 7) (BDA, São Romão de Neiva, Book 207; Library and Historical Archive of Public Works Ministery [LHAPWM], Montaria-Mor do Reino, 31).Footnote 3

Since the project in São Romão de Neiva was successful, in 1799, João Baptista do Desterro was invited by the general abbot of the Congregation, Manuel de Santa Rita Vasconcelos, to apply his project on a larger scale in the parish of Estela (Póvoa de Varzim). After 40 years of mismanagement of the lands of Estela, this monk was nominated to develop a truly remarkable action on a larger scale than the one developed in São Romão de Neiva (Ramos 1977; Oliveira 1997).

However, the presence of large patches of pine trees on the coast of the parish of Estela is already visible throughout the seventeenth and eighteenth centuries. The end of the seventeenth century and the first three decades of the eighteenth century are defined in this area by the deforestation of trees. However, regarding vegetation cover, there is an immense area of different species of scrubland, and its planting was even favoured by the inhabitants over cereals since, in this way, they could easily escape the obligation to pay rents of 25% of the total production. At the end of the seventeenth century, villagers cut down pine trees and reeds, having been condemned for these practices. Still, between 1726 and 1730, the cutting down of pine trees led to a loss of more than 10 000 cruzados in pine trees, and the villagers were imprisoned for five days (BDA, São Martinho de Tibães, Books 30 and 31). Pine trees are indicated in practically all the land contracts from 1747 (BDA, Congregação de São Bento de Portugal, Book 143 and 144). In 1758, the local parish priest mentioned that pine tree density was so high that it was impossible to see the Atlantic Ocean and the neighbouring parishes. His only view over the parish was of pine trees (Capela et al. 2009).

In the first three years after arriving in Estela (1799–1802), João Baptista do Desterro plowed the land—making it produce about 200 bushels of cereals and garlic—and distributed it to the new owners. With a special water pump, he converted small lagoons and watercourses into marshes and these into cultivated land. This monk built and improved Estela's religious, residential, and agricultural buildings in less than a decade (BDA, São Martinho de Tibães, Books 145 and 501).

Nevertheless, his most incredible legacy, which is still visible today, was the planting of a pine forest by the sea (Fig. 8), about 3,63 ha, with the primary purpose of preventing the advance of the sands, damaging the inhabitants' and the monastery of São Martinho de Tibães properties, as well as drying out the wetlands (evidence of Cávado paleo estuaryFootnote 4). This pine forest extended from the south of the parish of Apúlia to the limits of the parish of Estela with the parish of Navais, in the intermediate zone between the sands and the cultivated fields (Ramos 1977; Oliveira 1997).

Fig. 8
figure 8

Estela parish reforestation by São Martinho de Tibães Monastery (1799–1810)

We have yet no data on how the plantation was done, nor have it been recorded any purchase of pine kernels for this parish. It probably could have used pine kernels from the old pine trees, a technique João Baptista do Desterro would have known about due to his experience in São Romão de Neiva. Nevertheless, the Tibães pines trees could also have been transplanted to Estela between 1787–1789. Several pine trees were planted around the new wall that had been built (Fernandes et al. 2015). The monastery of São Martinho possessed the only plant nurseries in the region (Oliveira 1979) and where it could then breed these species and transplant them (BDA, São Martinho de Tibães, Book 501). The species used in the forestation of Estela is also unknown. Although there is no indication of the pine species used, and there is only a distinction in the land contracts drawn up by Frei João Baptista do Desterro between young and older pines, we found reference to "young pines and this stone pine". Therefore, it is assumed that another species would have been used to make this distinction, such as the maritime pine or the Flanders pine (BDA, São Martinho de Tibães, Book, 145). However, besides the fact that this pine forest served as a defence against the sands and that there are still vestiges of this grand plan, it was also the target of the peasants' axe.

A victorious battle against the drift sands?

The afforestation of the dunes was one of the most essential and successful chapters in Portugal's history of forestry development. The failed attempts at the end of the eighteenth century in Vieira and Aveiro were followed by the first successes in fixing the dunes of the Lavos coast, although these were short-lived. Only in the second half of the nineteenth century did joint efforts to settle these vulnerable areas intensified. In the post-Civil War period of 1832–1834, the work of forestation of the dunes was resumed. Pine trees were planted on the south bank of the Cávado. Their use was legislated, preventing grazing, bush clearing, and the drying of clothes (Lopes 2019), and even part of the pine nut for the reforestation of this area came from the lands, which until 1834, belonged directly to the Monastery of São Romão de Neiva (Esposende Municipal Archive, Câmara Municipal de Esposende, Book 1251). In 1848, Peniche Municipality took the initiative of afforesting the commons to prevent the sterilization of its fields by the sands from nearby beaches (Freitas 2004). In 1850–1851 sowings were made near the mouth of the river Liz and in the dunes of the Leiria pine forest. In 1866–1867, seeds were sown in the pinewoods of Pedrógão and Urso. However, the 1860s were a crucial moment in Portuguese forestry policy as the management of State woodlands, which until then had been the responsibility of navy officers and military engineers, became the responsibility of specialized technicians initially trained abroad and, after 1865, in the Instituto Superior Florestal (Devy-Vareta 1989). In the 1870s and 1880s, the afforestation of the dunes was the main priority. From 1881 to 1891, systematic sowing occurred in the dunes of Camarido (Mendia 1881), S. Jacinto, Gafanha, the Lavos coast, Leirosa, Liz, Peniche, Trafaria, Caparica and Vila Real de Santo António. Of the 37,000 hectares of dunes to be forested at the end of the nineteenth century, only 2,891 hectares had yet been afforested. Only with the Forestry Plan, in the first three decades of the twentieth century, was this mission of fixing the dunes completed. The success of this work is demonstrated when no one hears about and writes about the need to preserve the dunes' natural vegetation in areas where there were only vast stretches before the Forestry Services' fixing and afforestation action of sand without any vegetation (Vieira 1995).

Nevertheless, in our case study, at the end of the eighteenth century, all attempts to fix the sandy soils did not achieve all the desired goals. Communities and animals consumed the plants, and agricultural and grazing practices threatened their growth. At the same time, the strong winds and lack of support for the growing stems exposed the plants to salinity, causing them to grow on the ground rather than upwards, and the sand continued to deposit on agricultural fields and inhabited areas.

The woods' regeneration speed was incompatible with the populations' needs or the incursion rate of the sands. Despite the close control by the local institutions such as the Monastery of São Romão de Neiva or the House of Bragança, with their officials to watch and sanction the plantation or undue cutting of vegetation, this did not prevent the populations from woodland abuse (BDA, São Romão de Neiva, Book 207). The owners grazed their cattle next to these trees, which grew marram grass and barley around them. They cultivated it to keep them warm, cook or fertilize the fields and bedding for animals. In Estela, despite the efforts to forest the coast, the Tibães Monastery continued to allow the wood to be cut down free of charge if it was to be used to make land siding or for the settlers' buildings (BDA, São Martinho de Tibães, Books 145 and 501).

Pinus sylvestris, a species mentioned in the afforestation between the Lima and Neiva rivers, is common in dune stability. However, its establishment and abundance can vary greatly, so its application is only sometimes the most viable for all types of organic matter in drift sand soils (Sevink and Waal 2010). As Varnhagen (1836) mentioned, although some humid countries established pine tree nurseries and, after 5 or 6 years, transplanted them in pine holes, in Portugal, this could hardly be replicated. The transplanted pines did not grow much; if they did, they rotted. The indication was to sow through the pine kernel. However, as de Oliveira (1979) mentions, the attempts of 1801–1803 to plant pine nuts also ended in significant failures, as the seeds did not prosper due to the long and harsh winters that marked the end of the eighteenth century and the beginning of the nineteenth century in Northwest Portugal (Silva 2019).

Simultaneously the political context and the passage of French troops at the end of the 1800s, killing hundreds of villagers and destroying everything they passed through, put these reforestation actions on pause (Oliveira 2005; Soares 2009).

With the definitive implantation of Liberalism in Portugal and the definitive closure of the monasteries analyzed, their properties and the commons they managed were partially privatized, not ceasing to be areas of pine forest, given their importance for fixing the sandy soils and protecting the agricultural fields (Viana do Castelo District Archive [VCDA], 4.87.2.14). In other areas, as mentioned above, the Mata do Camarido passed into the hands of the General Administration of Forests, being for several times afforested. The concerns with the sanding of the fields throughout the nineteenth century show that the dune instability ceased very late. Still in the middle of this century, there were again requests in the south of Cávado River for taxes to forest the coast with pine trees and to place hedges (Lopes 2019) and requests for district support for the purchase of pine nuts in the coastal area between the Lima and Cávado rivers (Lopes 2020). In 1868, the Portuguese engineers Ribeiro and Delgado (1868) reported that between the coast of the Douro and Lima rivers, there was a continuous strip of uncultivated and unpopulated loose sand on the seashore, supported by a few pine forests, particularly the pine forests of Estela, Apúlia and Fão, the pine forests between the rivers Lima and Neiva and those of Camarido, but which still seemed to fulfil their role of sand protection. Despite all the efforts, the dunes continued to advance (Guerra 1899). At the end of the nineteenth century, sand movements were also recorded, caused by strong winds and storms (Guerra 1899) and which may have continued into the first decades of the twentieth century (Alves 1996) (Figs. 9, 10 and 11).

Fig. 9
figure 9

Amorosa Beach (Chafé, Viana do Castelo) in 1958: houses and dunes. ©Viana do Castelo Municipal Archive [VCMA], Severino Costa, 1869

Fig. 10
figure 10

© VCMA, Severino Costa, 1870

Amorosa Beach (Chafé, Viana do Castelo) in 1958: Our Lady of Bonanza Chapel, houses and dunes.

Fig. 11
figure 11

© VCMA, Severino Costa, 605

Amorosa—Lordelo Beach Dunes (Chafé, Viana do Castelo) in 1968.

During the 1940s, in the framework of the Forestry Plan, which continued with the covering of 14,500 hectares of dunes, the dunes of Esposende, from the mouth of the Neiva River to Apúlia, were afforested in an area of 370 hectares, through maritime pine, acacia longifolia, firetree, arbutus tree, broom, and gorse, Portuguese crowberry and weeping willow (Direcção Geral dos Serviços Florestais e Aquícolas 1942).

With the exploitation of tourism as a national source of revenue increased from the 1940s, the great occupation of the coastline began: first in the South but gradually extending along the North coast (Freitas 2010; Cadavez 2013). Tourism brought the first significant seaside developments, housing estates, docks, hotels, restaurants, and gaming areas (golf and casinos). Population growth and the expansion of the consumer society also contributed decisively to changing the landscape of the coastal area (Figs. 9, 10, and 11). Second and holiday homes appeared, and private and municipal companies were set up to buy and sell groups of plots of land and ready-made flats. As civil construction increased, so did the exploitation of inert materials in rivers, dunes, and beaches. The high coastline exploitation has resulted in environmental degradation of the coastal area and has contributed to the intensification of beach erosion (Fig. 2) and social conflicts concerning its appropriation and exploitation (Amorim 2002). Inappropriate occupation of the coastal zone was followed by attempts to protect the capital invested, which were quickly threatened by the action of the sea. The impacts have worsened and reached catastrophic and irreversible situations (Granja 1990).

Final considerations

This article has tried to demonstrate that, simultaneously with the actions of the Portuguese State, at the end of the eighteenth century, private institutions, such as the Benedictine monasteries, also faced coastal erosion problems and sought to fix the dune areas of North-western Portugal. Throughout the eighteenth century, the State, private institutions, and individuals sought to reforest and regenerate their forests, with greater or lesser success. However, it was only in the second half of this century and particularly in the final years, as a result of economic, war, and scientific conditions, that there was a joining of forces, either through a set of regulations applied nationally or locally or by putting into practice various projects in different places in Portugal.

However, in the case of private institutions and, in particular, monasteries, whose land and forestry administration we have dealt with in this paper, corroborating Nicole Devy-Vareta's research, rather than resolving a question of ecological imbalance, Benedictine monasteries gave priority to economic development. Dune afforestation prevents the advance of sediments into cultivated land or drying out wetlands and converting them into agricultural space. It is also in this sense that despite the extensive documentation consulted, it must be understanding the silence of the historical sources around the development of the projects to fix the dune areas and the involvement of the communities in the pine plantations or the scarce references to the purchase of pine kernels or pine tree breeding greenhouses.

However, it is possible to verify that, to some extent, forestation projects such as that of João Baptista do Desterro immediately impacted the landscape and the containment of the dunes, leaving an indelible mark even today in the places where he passed. After this, landscape by the monasteries of São Romão de Neiva and Estela, the problems with sand invasions were lessened. Later, there would be no descriptions of land completely covered by sand as in previous centuries. However, these results would have been even more considerable had there not been abuses in using and exploiting these same patches of pine forest (the grazing and cutting of wood and scrub) or the wet and stormy climate that marked the transition from the 18th to the nineteenth century.

Nevertheless, the preparation of these plans by some monks who were perfecting the techniques of fixing the coastal areas and the drainage of marshes is also due to the influence of Enlightenment and Physiocratic ideas that, at least since the mid-eighteenth century, arrived in written form to libraries and privileged networks with scholars and scientists who come to Portugal with ideas from other parts of Europe or Brazil. The initiatives evidenced there were only one of many along the European coast. However, they reveal an interest that, since the mid-eighteenth century, is emerging in the need to know and regulate the coast and estuaries, which should come from the King, who, together with his enlightened ministers, should protect his subjects, promote the public good and flourish his kingdom. However, it is also evident from local documents that the subjects of the second half of the eighteenth century and early nineteenth century also had the will to promote the public good of their more or less privileged peers ingrained in their minds and actions.

Although anthropogenic action on the coast is often considered harmful, it proves its capacity to intervene and restore ecosystems, even for more than three centuries, whether on a national, regional, parish, or even individual scale. The empirical or scientific ability to transform deserts into green spaces, knowing the demands of the soil, and adapting the best species, such as maritime pine, stone pine, or marram grass and other sandy plants, allow stopping drift sands in some places. We can look at past forestry policies and formulate future coastal forestry policies, particularly the suitability of certain species or the adoption of nature-based solutions. We can also, through the past, contributing to a holistic understanding, know the coastal sectors most vulnerable and affected by coastal changes, which helps us formulate more conscious, knowledgeable, and sustainable policies in the long term, with proven successful results, ensuring the involvement of public and private actors.