Non-timber forest products (NTFPs) include all biological materials other than timber that are harvested from both managed and degraded forests for human use (Muir et al., 2020; Shackleton et al., 2011). According to FAO (1999) they are biological products, other than wood, derived from forests, other wooded lands, and trees outside forests. In cases where NTFPs are cultivated, such as in plantations, they play a dual role in supporting local livelihoods and contributing to biodiversity conservation (Solomon, 2016; Zhou et al., 2023).

They provide diverse income opportunities for non-industrial forest owners and rural communities. The expansion of NTFP plantations has been driven, in part, by increasing off-farm employment, reflecting changing rural labor dynamics (Zhou et al., 2023). Additionally, integrating them into forest plantation management can enhance biodiversity and ecological resilience, mitigating the shortcomings of conventional plantations. However, as noted by Ingram et al. (2014a), to prevent resource degradation, harvesting must be conducted under a sustainable framework. Without appropriate regulation, overexploitation may occur. Governance institutions, whether formal, international, customary, or market-based, must oversee and regulate NTFPs-based activities (Ingram et al., 2014b). Moreover, effective management practices, including policies that promote sustainable harvesting and community engagement, are influential for maximizing the potential of NTFP value chains (VC) (Bauhus, 2010; Chamberlain et al., 2019).

Amid calls for a transition to a bio-based economy, NTFP value chains are emerging as important drivers of rural economic development (Huber et al., 2023). In the Portuguese context, a wide range of NTFPs holds significant social and economic value. However, despite increasing concern for forest ecosystem health and livelihood diversification, there is still limited research on the value chain dynamics within the NTFP sector (Muir et al., 2020). Terms such as “market” and “value chain” are often used interchangeably to describe economic interactions (Gunasekaran et al., 2001), yet they refer to substantially different concepts. While markets capture transactional dynamics within a specific context and timeframe, value chains provide a broader analytical lens that traces how value is created, distributed, and governed across multiple stages, from production to consumption (Boscolo et al., 2025). In the case of acorns and pine nuts, adopting a value chain perspective is particularly relevant, as it allows us to integrate not only economic flows but also the socio-ecological and cultural factors that shape their production and use. The data gaps identified, underscore the need to involve value chain actors directly in data collection and validation, thereby improving the accuracy and reliability of value chain mapping. To address this challenge, we offer a holistic analysis of the acorn (Quercus spp.) and pine nut (Pinus pinea L.) value chains in Portugal, integrating socio-economic, and governance dimensions.

Social-ecological systems are complex adaptive systems where people and nature are closely interlinked (Reyers et al., 2018; Folke et al., 2016; Levin et al., 2013; Berkes et al., 1998). The social component refers to all human activities that include economy, technology, politics and culture. On the other hand, the ecological component refers to the biosphere, that is, to the part of the planet on which life develops (SARAS Institute, 2019). By integrating a socio-ecological approach perspective for mapping value chains, whether forest or agri-based, and treating the ecological and social components as more than resources for production, a holistic view is created, allowing for an integration of cultural and social aspects from different actors along the chain (Fabre et al., 2021; Belliggiano et al., 2024). This value chain analysis offers a structured approach to understanding the roles, relationships, and power dynamics among actors (FAO, 2007), as well as the economic, social, and environmental dimensions within VC. NTFPs VC are dynamic and diverse and can operate from local to national and global level (Boscolo et al., 2025; Ingram et al., 2018). As Escobedo Aguilar et al. (2018) note, mapping VC involves identifying key activities, such as production, transformation, commercialization, and consumption, and representing the flow of these activities across various actors, both direct and indirect. Direct actors include primary producers, harvesters, processors, traders, while indirect actors are the one providing support services like certification, therefore they could be service providers (Escobedo Aguilar et al., 2018). Products embody multiple layers of value, economic, social, cultural, and environmental (Ingram et al., 2018). Mapping the value chain also helps identify critical bottlenecks that limit competitiveness, offering opportunities for innovation and improvement (Escobedo Aguilar et al., 2018). It also serves as a tool to explore governance structures and identify strategic points for intervention and improvement (Boscolo et al., 2025; Humphrey and Schmitz, 2001).

While previous studies, such as Sacchelli et al. (2021), have conducted financial analyses of the acorn value chain, a comprehensive, end-to-end analysis has yet to be performed. The Mediterranean Forest Union UNAC has provided a foundational overview of the pine nut value chain in Portugal, offering an initial framework for understanding its dynamics within Mediterranean forest systems (Agri-ciência, 2014). However, the primary data collection, meaning the online survey and the participatory workshops conducted in this study allowed for a deeper analysis of the challenges and opportunities faced by actors and the governance model along the value chain. Our literature review further expanded our understanding of the adaptive governance mechanisms shaping these value chains, providing insights that go beyond the scope of previous reports and offering a more complete view of both value chains.

This study aims to map and analyze the acorn and pine nut value chains in Portugal using a socio-ecological systems lens. We argue that understanding these interconnections is key to highlight the potential of value chains to support sustainable forest and plantation management and uncover leverage points for landscape-level sustainability. Drawing on established value-chain methodologies (Kaplinsky and Morris, 2001; Escobedo Aguilar et al., 2018; Tallec and Bockel, 2005), and inspired by Sørensen et al. (2021) analysis of the cork value chain, we analyze the governance and socio-ecological relationships shaping acorn and pine nut value chains. The objective is to pinpoint practical challenges and opportunities, as well as potential leverage points for improving the sustainability and resilience of these two non-timber forest product value chains in Portugal.

The distribution of Pinus pinea (stone pine) and various Quercus species across Portugal provides essential ecological context and helps explain the seasonality and cultural practices linked to pine cone and acorn harvesting (Figures 1A,B). Several oak species are widespread throughout the country, including Cork oak (Q. suber L.), Holm oak (Quercus rotundifolia Lam.), Pyrenean oak (Q. pyrenaica Willd.), Portuguese oak (Q. faginea Lam.), English oak (Q. robur L.), collectively covering approximately 1.15 million hectares (ICNF, 2015). Figure 1A illustrates the distribution of major Quercus species, including Cork oak (Q. suber), Holm oak (Q. rotundifolia), and other oaks, and Figure 1B presents the distribution of Pinus pinea (stone pine) based on data from the 6th National Forest Inventory (NFI) from ICNF (2015).

Approximately 63% of this oak-dominated area forms part of traditional silvopastoral systems known as montado, especially prevalent in Alentejo, south of the Tagus River. The montado is a cultural landscape shaped by centuries of human-environment interaction (Pinto-Correia et al., 2011; Pinto-Correia and Kristensen, 2013; UNESCO, 2017) and is dominated by Cork and Holm oaks. It plays a key role in rural development, biodiversity conservation, and the provision of diverse agroecological and socioeconomic benefits (Moreno et al., 2018; Pereira and Tomé, 2004). In contrast, the northern region of Trás-os-Montes is characterized by different Quercus species (Figure 1A), reflecting the ecological diversity across the country.

Pinus pinea is a valuable NTFP in Portugal (Correia et al., 2025; Mutke et al., 2024; Santos Silva, 2023). It is primarily concentrated in the coastal regions of Alentejo and Algarve, particularly within managed stands. Although stone pine accounts for just 6% of Portuguese forests, its area increased by 12% between 2005 and 2015 (ICNF, 2015) reaching 194,000 hectares. In Alentejo, stone pine stands are found both as pure plantations and interspersed within montado systems, particularly in the Sorraia and Sado river basins. These pine stands account for nearly all pine cone production, although they represent only 53% of the total Pinus pinea coverage in Portugal (ICNF, 2015).

Acorns, the seeds of oak trees, have long held cultural, nutritional, and economic significance in Portugal. Traditionally used in bread-making (Zocchi et al., 2022) and livestock feed, acorns were once a staple in both human and animal diets (Fonseca, 2020; López Bote et al., 2000; Mason, 1992). However, their use declined over recent decades, primarily due to associations with food scarcity and social stigma (Fonseca, 2020). Today, a revival is underway. Small-scale producers and local initiatives are reintroducing acorns into the food system, drawing on traditional knowledge to promote innovative, climate-resilient food products (Moreira, 2023).

Similarly, Mediterranean pine nuts—the edible seeds of Pinus pinea—are among the world’s most valuable tree nuts, often called the “white gold of the forest” for their high market value. Pine nuts are harvested from both wild stands and plantations, with Pinus pinea forests spanning approximately 0.7 million hectares across the Mediterranean region (Mutke et al., 2012). In Portugal, pine nuts are a long-standing ingredient in traditional cuisine, commonly used in confectionery, rice dishes, and salads (DGDR, 2025).

The subsequent subsections provide a detailed explanation of each methodological step, while Figure 2 offers an overview of the overall approach.

A total of 36 validated responses were collected between January and September 2021: 20 pertaining to the acorn value chain and 16 to the pine nut value chain (Table 1). Although it was not feasible to define a parent population, Table 1 details the intended targets and the number of validated responses obtained for each value chain, disaggregated by segment.

Most respondents from the acorn value chain were small private companies (15). Other participants included cooperatives/consortiums (2), hybrid private-NGO structures (2), one NGO, and one individual producer. Most acorn enterprises operated with minimal staff: seven companies had only one full-time employee, while four employed two. Exceptions included one NGO with 11 employees, a cooperative with 30, and a hotel employing 50 staff. Seasonal employment was also limited, typically ranging from zero to two workers, with a few exceptions. The acorn sector surveyed reflected predominantly small-scale, local operations.

In contrast, the pine nut sector was primarily composed of private companies (14 out of 15), along with one public entity. Pine nut companies exhibited greater diversity in size: small firms dominated (1–5 employees), but some medium-sized enterprises (6–10 employees) and larger operations (37–108 employees) also were present but mainly for distribution and commercialization. With an average of around 26 full-time employees, pine nut enterprises exhibited a more specialized and structured profile than their acorn counterparts. Seasonal employment varied widely, from none to up to approximately 20 seasonal staff in the harvest season.

The participatory workshop engaged key actors from both value chains (Table 2). The acorn chain had the highest participation, with 21 attendees. Among these, producers were the most represented group, accounting for 10 participants, followed by 4 wholesalers, 4 retailers, and 3 actors from the Ho. Re. Ca. sector. In contrast, participation from the pine nut chain was limited, reflecting existing power asymmetries and underscoring the need for cross-sector collaboration.

Our comparative analysis of the acorn and pine nut value chains highlights the diverse pathways through which NTFP-based economies can evolve, blending innovation, cultural heritage, and sustainability. Despite their distinct challenges, both chains increasingly rely on innovation, multi-actor collaboration, and local value creation and retention for success. Whether navigating regulatory frameworks for novel foods, adopting context-sensitive mechanization, or valorizing traditional knowledge, innovation must be inclusive and grounded in place-based realities. Marketing and certification strategies that emphasize territorial identity and ecological value can help differentiate products and build consumer trust. Finally, adaptive governance models that empower upstream and marginalized actors are essential for achieving equitable value distribution and long-term viability. Unlocking the full potential of these NTFPs will require stronger collaborative frameworks, alignment with public policy, and investment in both social and technological infrastructure.

This study offers a comprehensive analysis of the acorn and pine nut value chains in Portugal, highlighting their contrasting stages of development, governance models, and pathways to promote innovation and collaboration. The acorn value chain, reflects a deep connection to cultural heritage, community-led innovation, and ecological restoration efforts, while contending with barriers related to market formalization, scalability, and infrastructure. In contrast, pine nut value chain, though structurally consolidated and market-oriented, faces persistent challenges such as price volatility, pest outbreaks, and climate-induced stressors.

Together, these case studies illustrate the complex, context-specific nature of NTFP systems and their critical role in rural development and bioeconomies. They underscore the need to understand value chains not as isolated economic processes, but as embedded within broader socio-ecological systems, shaped by historical land uses, cultural identities, governance dynamics, and ecological interdependencies. Recognizing and supporting this interconnectedness is key to designing effective interventions.

To unlock the full potential of these NTFPSs value chains, targeted policy support, adaptive governance, and inclusive stakeholder engagement are essential. Strategic investments in innovation, knowledge co-production, and horizontal and vertical linkages across the value chain can drive sustainable, culturally grounded development. Ultimately, reinforcing the cultural and territorial identities linked to NTFPSs, such as the acorn, can open pathways to differentiated markets that value provenance, tradition, and sustainability, while contributing to resilient territories and diversified livelihoods in Mediterranean forest regions.

Despite these contributions, this study has some limitations. The sample size was limited and may not fully reflect the diversity of actors and practices across Portugal. While participatory methods provided rich qualitative insights, they were not designed for statistical generalization. Moreover, informal and marginalized actors were underrepresented, despite their critical roles in both value chains.

Future research could address these gaps by expanding the sample size to better capture the diversity of actors and practices and by co-designing workshops and activities with stakeholders to strengthen participation. Involving a broader range of associations and actors may further enhance the process and its outcomes. For pine nuts, direct engagement with harvesters could provide valuable insights into traditional practices, working conditions, and their evolution under mechanization. Expanding the analysis to other Mediterranean contexts and conducting longitudinal studies would also enable stronger comparative insights and a deeper understanding of NTFP value chains over time.