Commonly used terms like ‘non-timber forest products’ and ‘non-wood forest products’ present inaccuracies, inconsistencies and lack consensus on a definition.
The term ‘environmental products’ is explicitly defined and proposed as an alternative.
The new term is operationalised through a typology with six dimensions.
This approach allows a broad classification of all biotic and abiotic products.
This typology allows for integration of forest products into wider classifications.
SUMMARY
The material relationships between nature and people are complex and rich, ranging from support to current consumption to safety nets and poverty reduction. The term ‘non-timber forest products’ (in many different guises) has been used for decades in attempts to group a wide range of products, such as barks, bulbs, caterpillars, leaves, and fruits, without consensus on the definition. Here we argue that a different approach to product classification would be beneficial. We propose the term ‘environmental products’ defined simply and eloquently as “tangible biotic and abiotic goods gathered from any biome or created through synthetic production”. We propose a typology with six dimensions: product type, mode of production, purpose of production, scale of production, resource tenure, and biome of origination. The typology allows for consistent and transparent delimitation of environmental products useful to actors with varying objectives. We apply the typology to two cases, illustrating that the older terminology is no longer needed.
Les relations matérielles entre la nature et les populations sont riches et complexes, allant d'un soutien à la consommation courante aux filets de protection et à la réduction de la pauvreté. Le terme ‘produits forestiers autres que le bois’ (sous toutes sortes de diverses terminologies), a été utilisé pendant des décennies dans un effort de regrouper un large échantillon de produits tels que les écorces, les oignons, les chenilles, les feuilles et les fruits, sans consensus sur une définition. Nous débattons ici le possible effet bénéfique d’une approche différente de classification de ces produits. Nous proposons le terme de ‘produits environnementaux’ défini simplement et avec éloquence en termes de ‘biens tangibles biotiques et abiotiques obtenus de tout biome ou créés par une production synthétique’. Nous proposons une typologie à six dimensions: type de produit, mode de production, visée de la production, échelle de la production, régime d’occupation des ressources, et origine du biome. Cette typologie permet une délimitation cohérente et transparente des produits environnementaux qui sera utile aux acteurs à objectifs variés. Nous appliquons la typologie à deux cas, illustrant ainsi que l’ancienne terminologie n’est plus nécessaire.
Las relaciones materiales entre la naturaleza y las personas son complejas y ricas, y van desde el apoyo y el consumo actual hasta las redes de seguridad y la reducción de la pobreza. El término ‘productos forestales no maderables’ (en su diversidad de formas) se ha utilizado durante décadas para intentar agrupar una amplia gama de productos, como cortezas, bulbos, orugas, hojas y frutos, sin un consenso sobre la definición. Aquí se sostiene que sería beneficioso un enfoque diferente para la clasificación de estos productos. Se propone el término ‘productos medioambientales’, definidos de forma sencilla y elocuente como ‘bienes tangibles bióticos y abióticos recogidos en cualquier bioma o creados mediante producción sintética’. Se propone una tipología con seis dimensiones: tipo de producto, modo de producción, finalidad de la producción, escala de la producción, tenencia de los recursos y bioma de origen. La tipología permite una delimitación uniforme y transparente de los productos medioambientales útiles para agentes con objetivos diversos. Se aplicó la tipología a dos casos, para ilustrar que la terminología antigua ya no es necesaria.
INTRODUCTION
Biomes such as forests provide a wide range of plant, fungi, lichen and animal products, including timber, firewood, fodder, medicines and foods. These products are physical objects comprised of whole individuals or specific parts, e.g. derived from bark, roots, fruits, leaves, resins, meat, or skins. Their occurrence and uses are ubiquitous. Worldwide, more than 40,000 plant species (Diazgranados et al. 2020) are used by more than five billion people (Shackleton and Vos 2022). The products make up a substantial part of total rural household income in tropical and subtropical countries – on average 28% of which more than three-quarters are from natural forests (Angelsen et al. 2014) – and their economic importance elsewhere is substantial, e.g. amounting to 71% of the value of annual roundwood production in 28 European countries (Lovrić et al. 2020). In general, such products are important in relation to current consumption, as safety nets and gap fillers, and in the fight to reduce poverty (IUFRO 2020, Smith-Hall et al. 2022). The product diversity also means variation in dimensions of production and use, e.g. a product may be collected or cultivated, or used for subsistence or commerce, with varying levels of importance to local well-being, national economies, and global production networks. Production may take place on state, community, or privately owned or managed land. Examples thus range from First Nation use of reeds (Phalaris arundinacea L.) in winter dance ceremonials in Canada (Kim et al. 2012) to using biotechnology to increase the production and trade of ginseng (Panax ginseng C.A. Meyer) in the Republic of Korea (Park and Lee 2023).
Given these products' widespread occurrences and importance, their accurate assessment is needed, e.g., to compare studies and develop appropriate policy recommendations. Methods for estimating values are available for most products (Angelsen et al. 2011, FAO 2016). There are challenges, however, when grouping these diverse products for analytical and communicative purposes. Two bodies of literature are noteworthy. First, there has been substantial progress in the last two decades in establishing structured approaches to assessing the contributions of ecosystems to human societies, from the Millennium Ecosystem Assessment (MEA 2005) to the work of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES 2022a). The latest version of the IPBES conceptual framework (Díaz et al. 2018) uses the term “material nature's contribution to people” – replacing “provisioning ecosystem services” – to capture the contributions of products, distinguishing four categories (energy; food and feed; materials; and medicinal, biochemical, and genetic resources). While useful as macro-level aggregates, these categories do not provide guidance or standardisation for finer-grained analysis. Second, in forestry, there is an unresolved debate on how these products should be termed and categorised. The term non-timber forest products has been widely used since the seminal book by De Beer and McDermott (1989), while the term non-wood forest products has been promoted by FAO (1999). Both terms remain contested, with no common agreement on definitions and what products should be included. Allied terms include minor forest products, special forest products, wild products, and secondary forest products (e.g. Belcher 2003). Attempts to clarify the terminology (Ahenkan and Boon 2011, Belcher 2003, Chamberlain et al. 2018, Muir et al. 2020) and move towards a unified definition (Mantau et al. 2007, Shackleton et al. 2011a) have been unsuccessful.
Rather than accepting that there is no way to adequately classify this wide range of diverse products, we propose an alternative: to develop forest products classification as a subset of all products produced across biomes and ecosystems. In other words, a general product classification system that provides a solution for organising the multitude of products from the environment, including forests. A transparent and logical typology of plants, fungi, lichen, and animal products harvested from all biomes, from forests to grasslands and aquatic environments, is needed to provide clarity and consistency. While acknowledging that any systematisation can be debated, much can be gained by reaching agreement on what is being discussed. This is much more than an academic exercise. An explicit and nuanced system would facilitate analytical focus, ease comparative studies, improve standardised data collection, and enhance communication with decision-makers and the public. Arguably, achieving better terminological clarification in forestry has received renewed importance with the increasing complexity of the forest sector as it is integrated into climate change (Bonan 2008), ecosystem services (Acharya et al. 2019), and the bioeconomy (Smith-Hall and Chamberlain 2023).
In this paper, we propose a new term with an associated typology. We illustrate the use of the typology by applying it to the cases of trade in commercial medicinal plants from Nepal, and an iconic medicinal forest product from the United States.
CHALLENGES WITH CURRENT TERMINOLOGY
The wider non-forest-specific conceptual developments are useful to position products within the general framework of nature's contributions to people, even across different knowledge systems (Díaz et al. 2018). However, the key product-relevant term “material nature's contributions to people” is broad and only operationalised by specifying the above four reporting categories. Moreover, the term “Material NCP” does not appear destined for widespread use: it is technical, vague, and lacks attractive, intuitive elegance. Hence, the wider non-forest work is not sufficiently developed to serve as a general product classification scheme.
The same is true for the terminology developed in connection to forests and forestry, specifically the terms non-timber forest products and non-wood forest products – starting with the problem that these are named according to what they are not. Box 1 provides widely adopted definitions and remarks on their main shortcomings. There are six main challenges related to these terms:
Sectorial limitation. Historically, interest in nontimber products has been driven by demand for better documentation of the value of forests (e.g. Godoy et al. 2000, Peters et al. 1989) to facilitate forest conservation (Sheil and Wunder 2002). However, recent advances in understanding the economic importance of forests to local communities (Angelsen et al. 2014) have shown that many products are produced inside and outside forests and that the latter may be of significant importance, e.g. in sub-Saharan West Africa (Pouliot and Treue 2012, Reiner et al. 2023). Thus, from the viewpoints of households and industries, as well as initiatives to facilitate individual species conservation, a forest sector-focused terminology may be a limitation rather than a strength. The sectoral focus also has the disadvantage of leading to proposals for new terms, such as agroforestry tree products (AFTPs, Leakey 2012, Simons and Leakey 2004) that suffer from the same set of challenges.
Major product bias. Modern ‘western’ forestry has focused traditionally on timber (Pretzsch et al. 2014, Williams 2003), however, timber species constitute a mere fraction of the number of forest species used worldwide. While timber may be dominant in value terms in many locations, this is far from always the case. Arguably, de-emphasising the distinction between timber and other products could lead to more holistic forest management better able to encompass increasingly complex objectives as public demands to forests change, such as through synergistic compatible production of different species on the same unit of land (Balasso et al. 2023) or more than one product from the same species, e.g. Tabebuia spp. providing inner bark for medicine as well as timber (Gómez and Luiz 2018).
Institutional bias. The major reason for the UNFAO to prefer non-wood versus non-timber appears to be institutional (Belcher 2003, Mantau et al. 2007): to enable the use of an existing classification system and to establish a bureaucratic unit separate from those dealing with wood products. Excluding wood products from the non-timber definition is also pursued to ease the compilation of statistics (Muir et al. 2020). Institutional convenience, however, should not surpass the need for improved classification and data.
Omitting abiotic products. It has been argued that nontimber/non-wood definitions should exclude abiotic (non-living) products, such as clay and sand, as these pose different sustainable use and conservation issues (Shackleton et al. 2011a). From an accounting or valuation point of departure, however, a definition and typology would benefit from being comprehensive and include biotic and abiotic products.
Parsing according to specific interests. Shackleton et al. (2011a) noted five important ways that the terms non-timber/non-wood have been narrowed to only include: (i) wild-harvested products, (ii) indigenous products, (iii) subsistence products, (iv) consumptive use of products, and (v) products that bring local benefits. Such distinctions may also be found in certification standards, e.g. the Union for Ethical BioTrade (UEBT 2020) lists different types of cultivation. These are important observations as they point towards key dimensions distinguishing the wide array of products, including modes of production (e.g. natural regeneration vs cultivation) and purpose of production (e.g. commercial vs subsistence). Of course, each delimitation brings along a new set of terminological challenges, e.g. defining the differences between wild harvesting and domestication.
Product-service divide. While the more widely used definitions in Box 1 focus on products, there are alternative terms that include both products and services, e.g. non-wood goods and services, non-wood forest benefits, or forest goods and services. While some product prices include non-material components, such as healthcare services in connection to medicinal plants (Pouliot 2011) or premium payment for fair-trade products (Naegele 2020), including products and services in the same term/definition will likely reduce simplicity, accessibility, and applicability. To arrive at a complete framework for assessing environmental contributions to people, however, the present environmental product definition and typology should be expanded with an environmental service definition and typology.
The six challenges illustrate the existing terminology's limitations while pointing to possible solutions. In the following, we respond to the call for a typology for non-timber/ non-wood products (Shackleton et al. 2011b) but taking the path of first proposing a unifying term and then an associated typology that coalesce definitions.
ENVIRONMENTAL PRODUCTS – DEFINITION AND TYPOLOGY
The new term and typology should (i) be relevant to all material contributions of nature to people and (ii) enable comparison between products through (iii) the use of explicit dimensions that are (iv) operationalised through existing approaches facilitating empirical assessment. Thus, whenever possible, we make use of available building blocks while prioritising clarity and typology flexibility over contemporary practical concerns such as the continuation of existing data reporting systems (a continuation that Muir et al. (2020) chose to emphasise). The term and typology should be meaningful to reality and allow actors, from researchers to policymakers and intervention organisations, to position specific products and initiatives in the rich landscape of material connections between nature and people. Thus, we aim at a typology that captures the myriad ways products from all biomes and ecosystems are produced and contribute to human well-being.
BOX 1 Widely used definitions and their main short-comings
A chronological overview of major non-timber/non-wood forest product definitions is available in Ahenkan and Boon (2011), Pullanikkatil and Shackleton (2019) and Muir et al. (2020). Two widely used definitions are:
The De Beer and McDermott (1989) definition: Non-Timber Forest Products (NTFPs) encompasses all biological materials other than timber, which are extracted from forests for human use.
Problems: The prefix ‘non’ may have negative connotations (Belcher 2003, Mantau et al. 2007); the distinction between timber and non-timber is not always straightforward; 1713 forest definitions with huge differences have been recorded (Lund 2023) making it variable what is included and excluded; extraction means human harvesting and thus exclusion of key products such as fodder eaten directly by livestock (Shackleton et al. 2011a); the forest focus does not reflect rural realities where the same product can be harvested inside and outside forests.
The FAO (1999) definition: Non-wood forest products consist of goods of biological origin other than wood, derived from forests, other wooded land and trees outside forests.
Problems: The continued use of the ‘non’ prefix; the continued limitation to forests and trees (e.g. excluding products gathered in meadows); a wood/non-wood distinction that is not reflected in rural realities; the inclusion of products from outside forests in the term forest products.
The definition of environmental products
To move forward with the terminology discussion, our first proposition is to adopt the use of the term environmental products. This term has been used occasionally (without being defined) in fields such as chemistry and remote sensing (e.g. for land use changes, Gutman et al. 1995) since the early 1990s. The main use, however, has been in relation to forest products. Early work to quantify total rural household income in low- and middle-income countries (Angelsen and Wunder 2003, Campbell et al. 2002, Cavendish 2000, 2002, Sjaastad et al. 2005, Vedeld et al. 2004) led to widespread use of the term environmental income: “income (cash or in kind) obtained from the harvesting of resources provided through natural processes not requiring intensive management” (PEN 2007: 19). While the term environmental products was not defined in this early work, resultant studies provided useful examples of the valuation of these products (e.g. Angelsen et al. 2011, 2014).
Building on this work and the aforementioned non-timber/ non-wood definitions and shortcomings, we define the new term: environmental products are tangible biotic and abiotic goods gathered from any biome or created through synthetic production. This definition has three important implications:
It includes goods but not services. Goods are tangible products that provide utility and satisfy human wants (Milgate 2008), either directly (e.g. firewood) or indirectly (e.g. livestock browse). This clear distinction between products and services follows the work with ecosystem services and nature's contribution to people (Díaz et al. 2018). Biotic goods include animals, plants, fungi, and lichens. Abiotic goods include water, soil, stones, sand, and salt. They also include all types of minerals (including metals such as gold, copper, and iron), peat, and fossil fuels (such as coal, natural gas, natural bitumen, and heavy oil).
It includes gathered goods and synthetically created products. Gathering is the act of removing parts of or the entire organism from its habitat (IPBES 2022b) or any quantity of abiotic material. We distinguish three types of gathering: collecting, harvesting, and mining. For renewable natural resources, inspired by Olsen and Bhattarai (2005), collecting takes place in less intensively managed ecosystems (such as natural forests and meadows), and harvesting in more intensively managed ecosystems (such as plantations and agroforests). Gathering of abiotic products is termed mining. Synthetically created products cover artificial production in factories and laboratories of products that exist in nature; environmental products produced this way remain environmental products. An example is salt produced in solar evaporation ponds. Note that the definition excludes manufactured products created from the use of environmental products, such as medicines or furniture.
It includes all biomes. A biome is the largest global unit of ecological classification that can be recognised (e.g. forests, wetlands, tundra); each biome is made up of a number of ecosystems (e.g. tropical rain forest), each a functional unit arising from the interaction of the abiotic environment with plant, animal, and microorganism communities (Kumar, 2010). Here, we adopt the Groot et al. (2010) classification identifying 12 biomes: marine/open ocean, coastal systems, wetlands, lake/rivers, forests, woodland and shrubland, grass/rangeland, desert, tundra, ice/rock/polar, cultivated, and urban. Note the inclusion of the two latter. It is possible to collect environmental products on agricultural land, e.g. fruits from transplanted bushes located in borders between agricultural fields (Hertog and Wiersum 2000), and in urban spaces, e.g. leafy vegetables and medicinal plants in the city of Kampala (Mollee et al. 2017). It is also possible to harvest environmental products, such as crops. Hence, from an environmental product point of view, there is no natural border between forest products and agricultural crops. In general, for sectoral analyses of environmental products, an arbitrary boundary is needed along the production continuum from collection to cultivation (Poe et al. 2013, Wiersum 1997) with fuzzy boundaries between these production modes making it difficult in practice to clearly distinguish them in all situations. One way could be to distinguish environmental products requiring less than annual management inputs. This would include trees harvested in plantations for wood or exudates (such as rubber or gum arabic); trees, bushes, and perennial herbs harvested in agroforests; and plants that are not tended in urban spaces. Conversely, products cultivated in home gardens and trees grown for conventional fruits and nuts in plantations, e.g. apples or almonds, requiring annual management inputs could be considered agricultural products. Note that in some cases this means that the same product may be counted as either a forest product or an agricultural product dependent on its mode of production, e.g. the medicinal herb Swertia chirayita (Roxb.) H. Karst. (Cunningham et al. 2018) collected in forests is a forest product while it is an agricultural product if harvested as a crop on agricultural land. This makes it difficult to establish a clear “ecosystem-fence” around products; hence, studies should be explicit in describing applied sectoral inclusion criteria for species with fuzzy boundaries.
Many existing agreements and activities contain a string of terms that are typically subsets of environmental products. Connections to such terms and their relationship to the proposed typology are illustrated in Box 2.
The typology of environmental products
To operationalise the definition and promote a consistent and transparent use across actors with varying objectives, our second proposition is an environmental product typology that allows for decomposition along six dimensions (Table 1). Bailey (1994) characterised a typology as qualitative, multidimensional, conceptual, and commonly used in the social sciences. The allied term taxonomy is similar and usually used to classify empirical entities, often in a hierarchy in the biological sciences. Four classifications for environmental products are found in the literature. Cavendish (2002) presented a taxonomy of environmental resource use for his Zimbabwe study site; this is essentially a product classification (e.g. wild foods) with economic characteristics (e.g. consumption goods or input into asset formation). Mantau et al. (2007) proposed a complex typology involving forest resources, products and services, and users, attempting to develop a holistic approach that could be used across all situations, e.g. in relation to value chain studies. Byron and Arnold (1999) and Newton et al. (2016) proposed taxonomies characterising the relationships between forests and livelihoods.
We propose an alternative centred on product characteristics. We identify six product dimensions and describe each using literature-derived descriptors. This allows for a standardised specification of any environmental product in any study, e.g. the dimension “Production Mode” distinguishes collected, harvested, mined, and synthesised products.
BOX 2 Building bridges to terms applied in existing legislation, agreements, and initiatives
The term environmental products is closely related to an array of existing terms in currently implemented texts and activities. Suc terms include agro-ingredients, biodiversity products, biological resources, biotrade products, medicinal or biochemical or geneti resources, minor crops, natural resources, specialty crops, and wild crops. Here we illustrate such connections. Acceptance and us of the term environmental products by policy-makers, researchers, and international and national organisations could reduce th unnecessary plethora of similar terms that actors need to contend with, thus increasing terminological transparency. Examples are:
Environmental products and the Convention on Biological Diversity. The convention uses the term biological resources t include “genetic resources, organisms or parts thereof, populations, or any other biotic component of ecosystems with actua or potential use or value for humanity” (CBD 2011: 4). In the typology, this would be biotic products of any type, regardles of production (whether mode, purpose, or scale), tenure, and biome. The CBD definition is very broad which is to be expecte in an encompassing global treaty; the typology proposed in this paper allows for a structured breakdown into tangibl subcomponents.
Environmental products and the UNCTAD BioTrade Initiative. This adapts the CBD use of biological resources and specif biotrade products as “those coming from wild collection or from cultivation practices. The latter refers to products derive from cultivation of domesticated and wild varieties through activities such as agriculture or aquaculture” (UNCTAD 2020 10). Using the typology, the emphasis is thus on biotic products that are collected or harvested for commercial purpose regardless of production scale, tenure, or biome.
Environmental products and the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services. The IPBES conceptual framework (Díaz et al. 2018) operates with the concept of material nature's contribution to people. The proposed typology provides a way forward to breakdown this wide concept into specific components.
TABLE 1
A typology of environmental products: dimensions and descriptors. To keep the table simple, it includes only the main descriptors for each dimension

Taking the point of departure in the environmental product definition and the six challenges above, the dimensions are: product type, production mode, production purpose, production scale, tenure (access and ownership), and biomes (where an organism is naturally produced). An overview of each dimension and its descriptors are provided in the following, acknowledging that further work is needed to develop many of these:
Product Type: We include four descriptors for this dimension. Regarding the Group descriptor: here we use the six major product groups proposed by The United Nations Environment Programme's work on a global assessment of the economics of ecosystems and biodiversity: food, water, raw materials, genetic resources, medicinal resources, and ornament resources (Groot et al. 2010). These may overlap for some products, e.g. the same fruit may be a food, a raw material, and a medicine, and deliberation is needed to develop more meaningful groups. Regarding the Taxonomy descriptor: while this can be applied using existing taxonomic classifications, such as the six-kingdom system (Cavalier-Smith 1998) for biotic products, it would be useful to develop simple meta-labels useful for analytical purposes. The Poverty Environment Network code list provides a detailed example of products recorded in structured household surveys in 24 tropical and subtropical countries (PEN 2008) and could provide a useful starting point for label development as could Cavendish (2002). Regarding the Status descriptor: for biotic products, this could use the nine categories in the IUCN Red List Categories and Criteria (IUCN 2022). For abiotic resources, an initial distinction could be between rare and non-rare products, e.g. using sources like Hazen et al. (2015). Regarding the Tariff descriptor, while there are many structured ways to gather data on subsets of environmental products, including the Harmonized System (HS), the Central Product Classification (CPC), and the International Standard Industrial Classification of All Economic Activities (ISIC) (Muir et al. 2020), there is no standard product classification. Much work is required to develop national and international product classifications that allow continued and structured statistical data collection according to key species and products (Chan et al. 2015).
Production Mode: Inspired by Harris (1989) and Wiersum (1997), mode of production reflects increasing input of human energy per product unit. We distinguish four main modes: collecting, harvesting, mining and synthesising. Collecting takes place in populations whose reproduction is not directly nor actively promoted by humans. This would include foraging and fishing from natural populations but also collection of products such as birds' nests and bat guano. Note the focus on populations rather than species; a species can thus span different modes of production (IPBES 2022b). Harvesting is obtaining products through the repeated deliberate sowing and management of organisms in natural habitats or habitats manipulated by humans. This includes products obtained through domestication: the harvesting of genetically altered species, e.g. through selection of characteristics that display desirable phenotypic features distinguishing them from wild progenitors (Larson et al. 2014, Piperno 2011) such as in aquaculture, different forms of crop farming and home gardens. Focusing on plants, further subdivision of harvesting is possible using the distinctions made by Brinckmann et al. (2022): this includes agroforestry and natural fostering (including enrichment planting, transplanting, wild simulated plantings and ecosystem stewardship). Mining is undertaken to obtain environmental products that are mineral constituents of the earth's crust, either through surface or underground mining, at different scales, from artisanal to industrial. As noted above, mined products include metal ores, construction materials like gravel and sand, and naturally occurring mineral substances like shilajit. Synthesising is the production of environmental products in factories or laboratories. Such production is common for some abiotic products, such as lab-grown diamonds, and may soon expand to include substantial amounts of biotic products. For instance, the caterpillar fungus Ophiocordyceps sinensis (Berk.) G.H. Sung, J.M. Sung, Hywel-Jones & Spatafora, traditionally collected in Tibetan and Himalayan alpine grassland, can now be large-scale year-round produced in plastic buckets in factories with controlled environment at low altitude (Li et al. 2019). Total species production is thus the sum of collection (from natural populations), harvesting (from cultivated and domesticated populations), and synthesised output. Another approach to modes of species production is to distinguish management practices: Wiersum (1997) identified different forms of purposeful regeneration, while Belcher et al. (2005) distinguished three types of natural forest management based on the intensity of interventions. There also may be taxa-relevant considerations, e.g. for a discussion of the wild production of vertebrates, see Child et al. (2019).
Production Purpose includes the distinction between subsistence and commercial that has been important in past terminology discussions and empirical analyses (e.g. Angelsen et al. 2014). Subsistence is the production of products for direct household consumption (PEN 2007), and commercial production is for sale outside the household. Production also can be for cultural purposes (e.g. Baumflek et al. 2022).
Production Scale is useful to distinguish types of operations. Here we propose a simple initial distinction using volume (low/high), value (low/high), and depth (national/international trade) to cover variation. For instance, it has been argued that micro, small, and medium-enterprises are important to realise economic benefits from environmental products in Africa (Cunningham 2011) and that artisanal small-scale miners using traditional hand tools may constitute an economically important segment of mining at national and global levels (Schwartz et al. 2021). The environmental income and livelihood literatures typically focus on the household as the unit of analysis (Angelsen et al. 2011) and there has been limited integration and upscaling of data to inform larger-scale interventions (Smith-Hall et al. 2023).
Tenure covers ownership of and access to production units such as a forest stand. It is necessary to distinguish formal or de jure owners (state including provincial and local governments, community, individuals) from de facto users and acknowledge variations in the degree of rules enforcement (PEN 2007). This results in a large number of possible empirical tenure regimes on the ground. PEN (2008) identified 63 possible combinations, ranging from the state being the de jure owner and user with a high level of rule enforcement, e.g. in a well-protected national park, to situations of no rule enforcement leading to de facto open access.
Biome: The 12 biomes identified by Groot et al. (2010) are presented in Table 1; each contains a huge number of environmental products. These can be further subdivided into 26 ecosystems. Biomes and ecosystems also can be disaggregated at the national level, e.g. Stainton (1972) distinguished 35 forest types in Nepal, or according to management objectives, e.g. dividing the forest biome into natural forests, managed forests, and plantations (PEN 2007).
The importance of each dimension, and the need for further disaggregation, will vary with a study's or an initiative's contextual situation and objectives. Further standardised subdivision is possible for each descriptor. If the dimensions are consistently reported in future studies, this would facilitate the targeted selection of examples for analysis and reporting purposes.
In the following, we provide two examples of product-level typology use.
USING THE TYPOLOGY OF ENVIRONMENTAL PRODUCTS
The typology can be used to characterise studies by describing them in relation to each of the six dimensions. Such characterisations can be further enriched by disaggregation of dimensions as relevant to study objectives, e.g. a study focused on harvester behaviour in connection to collection of commercial food plants might benefit from differentiating between dedicated and opportunistic collection. As the typology is conceptual, we provide examples of its use (Table 2).
Example 1: Application to a body of literature – the trade in O. sinensis in and from Nepal
The fungus O. sinensis parasitizes ghost moth caterpillars and the resultant complex is gathered when the snow melts in the high Himalayas around mid-May; after primary processing (removal of soil), the product enters a global production network spanning from the Himalayas across Tibet into China that constitutes the dominant market; mean harvester prices in Nepal are above US$ 12 000/kg making this probably the most valuable biotic environmental product in the world (Smith-Hall and Benneke 2022). Most production is from the wild, but expanding factory production is taking place in China (Li et al. 2019). The product used to be consumed in minor quantities for subsistence purposes in Nepal's high-altitude gathering communities (Devkota 2006) but following a rapid price increase in the first decade of the new millennium (Shrestha and Bawa 2013), almost everything is exported. The end use is medicinal for a range of conditions, including improving the immune system and blood circulation, controlling diseases, enhancing sexual potency, and curing cancer (He et al. 2022). The collection takes place on de jure state-owned land that is sometimes subject to de jure community management and regulation of access rights; access issues can lead to severe conflicts impacting high-altitude livelihood strategies (Pant et al. 2017, Pouliot et al. 2018). Collection takes place in grasslands, more specifically, using the TISC (2002) vegetation type terminology, in upper alpine meadows, dry alpine scrub, moist alpine scrub, as well as in the high alpine vegetation in the trans-Himalayan zone. A brief typological description of this product is thus: low volume but high value collected vulnerable commercial medicinal fungus-larvae complex produced in de jure state-owned alpine grasslands and traded internationally. It has no tariff code. This product also illustrates the limitation of the terms non-timber/ non-wood forest products: it occurs above the tree line and cannot logically be classified as a forest product, which is commonly done (e.g. Wallrapp et al. 2019).
TABLE 2
Examples of the use of the environmental product typology in cases from Nepal and the US

Example 2: American ginseng: production from multiple ecosystems for diverse markets
American ginseng (Panax quinquefolius L.) is an herbaceous forest plant native to the eastern hardwood forests of North America. This medicinal plant grows primarily in mixed mesophytic forests in three ecoregions (Bailey 1995): Eastern Broadleaf Forest Province, Central Appalachian Broadleaf Forest Province, and mountainous areas of the Southeastern Mixed Forest Province. Most production of collected ginseng occurs in five southern states where more than 75% of the forest area is in private ownership. As access to ginseng habitat is difficult to control, and poaching is known to take place, de facto open access is plausible (Frey et al. 2018). The most valuable ginseng (i.e., wild-harvested) is collected from natural populations, though it has been cultivated under shade cloth for more than a century. The price for collected ginseng ranges from about US$ 1000/kg to over US$ 2000/kg. Shade-grown cultivated ginseng is significantly cheaper at about 10% of the price and is for a different market. Over the last three decades prices have been increasing, while collection levels have declined (Schmidt et al. 2018), an indication of over-collection (Frey et al. 2018). Forest farming, a cultivation method that mimics natural regeneration, is becoming popular and may be a feasible alternative production method to mitigate declining natural populations. Most production is for commercial gain with very little if any for subsistence, and most is for international trade, particularly to China. A brief typological description of this product: endangered medicinal perennial herb collected from natural populations in mesophytic hardwood forests for commercial purposes from de jure state and private land or cultivated under forest canopies or shade-cloth; internationally traded and assigned a tariff code.
CONCLUDING REMARKS
The terms non-timber forest products and non-wood forest products have been used for three decades, yet there is no consensus of their definitions. We propose an alternative term environmental products and provide an operational typology to classify products within this new convention. Simply, environmental products are tangible biotic and abiotic goods gathered from any biome or created through synthetic production. The typology is based on six dimensions that provide a standardised way to characterise these goods. This classification system positions forest products in their wider context. We discuss the limits of the definition and each of the dimensions, including how they can be further subdivided to facilitate empirical measurements. We hope this effort to harmonise and make terminology more transparent will diminish the use of less clear terms, including non-timber and non-wood forest products, enhancing comparisons of studies that include diverse types of products. In forestry, this approach will also eliminate the malpractice of calling products harvested outside forests as ‘forest products’.
We trust that this approach stimulates renewed thinking and analysis of the material relationships between nature and people. Measures of success will be the use of the term and typology in future publications and the emergence of a dialogue on possible modifications, including further development of measurable descriptors and the important step of expanding this work to include environmental services.
ACKNOWLEDGEMENT
This work was supported by the Independent Research Fund Denmark (Grant No. 0217–00158B), the Carlsberg Foundation (Grant No. CF22-0690), and the Organisation for Economic Cooperation and Development, Conservation Research Program Fellowship (no Grant No.). We thank two anonymous reviewers for comments and suggestions.