Indigenous Knowledge of New Guinea’s Useful Plants: A Review1
We present the first large-scale synthesis of indigenous knowledge (IK) on New Guinea’s useful plants based on a quantitative review of 488 references and 854 herbarium specimens. Specifically, we assessed (i) spatiotemporal trends in the documentation of IK, (ii) which are New Guinea’s most useful ecosystems and plant taxa, (iii) what use categories have been better studied, and (iv) which are the best studied indigenous groups. Overall, our review integrates 40,376 use reports and 19,948 plant uses for 3434 plant species. We find that despite a significant increase in ethnobotanical studies since the first reports of 1885, all islands still remain under-investigated. Lowland and montane rainforests are the best studied habitats; legumes, palms, and figs are the most cited plant families; and Ficus, Pandanus, and Syzygium are the most useful genera. Medicinal uses have received the greatest attention and non-native species have the highest cross-cultural consensus for medicine, underscoring the culturally enriching role of non-native taxa to New Guinea’s pharmacopeia. Of New Guinea’s approximately 1100 indigenous groups, 217 are mentioned in the literature, and non-endangered groups remain better studied. We conclude that IK can contribute significantly to meet rising demands to make New Guinea’s landscapes “multifunctional” and boost the green economy, but ambitious strategies will still be needed to mainstream IK and improve its documentation.
Key WordsBiodiversity ecosystem services indigenous people useful species
Indigenous and local communities occupy over 25% of the world’s terrestrial surface (Garnett et al. 2018) and for centuries have interacted with their native ecosystems to discover novel plant sources for foods, medicines, and fibers. The Asia–Pacific region is home to three quarters of the ca. 370 million indigenous people of the world (Dhir 2015), many of whom draw their livelihoods directly from forest-based ecosystem services (FAOSTAT 2017). New Guinea stands out within the Asia–Pacific for being its most bioculturally diverse region (Loh and Harmon 2005), where interactions among 1100 indigenous groups and 15,000 plant species can be studied across relatively short distances. New Guinea’s mountainous geography has resulted in steep ecological gradients and isolation among its inhabitants and promoted an unparalleled diversification of plant species, languages, and cultures (Stepp et al. 2005). Humans occupied New Guinea around 50,000 years ago (O’Connell and Allen 2015) and were intensely cultivating bananas (Musa spp.), taro (Colocasia esculenta (L.) Schott), breadfruit (Artocarpus altilis (Parkinson) Fosberg), sugarcane (Saccharum spp.), and the greater yam (Dioscorea alata L.) 6440 years B.C.E. (Denham et al. 2003; Lebot 1999). Today, many of these plants are still collected, transplanted, and cultivated from wild forms (Denham et al. 2003; Hyndman 1984).
Despite New Guinea’s global significance for biocultural conservation (Gorenflo et al. 2012; Mittermeir et al. 1998), publications on plant utilization by its indigenous groups have remained scattered, making quantitative syntheses difficult. Our current understanding about IK on New Guinea’s plants is based on studies that have focused on single plant taxa (Bau and Poulsen 2007; Motley 2004), few indigenous groups (Arobaya and Pattiselanno 2007; C. D. Cook 2016; Johannes 1975), small geographic areas (Avé 1998; Sillitoe 1995; Stopp 1963), and single-use categories like medicine (Holdsworth 1977) or food (Barrau 1959; French 1986). To date, Powell (1976) made the most comprehensive review of useful plants in the region based on 46 studies from mainland New Guinea. This resulted in a total of 146 useful plant families, 470 genera, and 1035 species. However, Powell recognized that the data available in the literature at the time was extremely uneven and inadequate. Subsequent efforts resulted in a series of regional reviews on medicinal (e.g., Holdsworth 1977, 1993) or food plants (French 1986), albeit these were politically restricted to Papua New Guinea. Thus, no comprehensive and up-to-date review on IK about New Guinea’s useful plants exists. This limits landscape-scale labeling initiatives, market recognition of useful plants, and publicizing cultural heritage to underpin forest conservation (Ghazoul et al. 2009).
Here, we explore the spatiotemporal evolution in the documentation of IK about plant utilization across New Guinea by quantitatively analyzing 130 years of data. Specifically, we ask (i) what are the spatiotemporal trends in the documentation of IK, (ii) which are New Guinea’s most useful ecosystems and taxa (plant families, genera, and species), (iii) what use categories are better studied, and (iv) how well have indigenous groups been studied and does research effort correlate with the extinction risk of indigenous groups. On the one hand, our review contributes to understanding large-scale patterns of IK on plants and paves the way for future documentation with indigenous groups missing in the literature. On the other hand, it sets a baseline for realizing the potential of New Guinea’s natural resources before massive habitat degradation occurs (Novotny 2010; Sloan et al. 2019). This is important given recent political commitments, where the Governors of Indonesia’s two New Guinea Provinces declared in 2018 to, among other things, conserve 70% of the forest cover for the western half of the island, strengthen the role of indigenous peoples, support indigenous communities to develop appropriate economic development activities, and increase access to markets (Cámara–Leret et al. 2019).
Our dataset was collected during 12 months and combines information from 488 references and 854 herbarium specimens. The literature review was made searching Google Scholar and the Kew Bibliographic Database using the following terms and their combination: ethnobotany, food plants, medicine, New Guinea, Papua New Guinea, timber, traditional medicinal plants, and traditional use of plants. This was supplemented with references cited in Papuaweb (www.papuaweb.com), Hide’s bibliographies of ethnobotanical research in West Papua (Hide 2014a, 2014b, 2015, 2016a, 2016b, 2017), and ethnobotanical information in herbarium specimens deposited at K and L (acronyms according to Thiers 2019). The combination of search terms and sources resulted in a broad coverage of references in English (n = 346), Bahasa Indonesia (n = 132), French (n = 8), Dutch (n = 1), and German (n = 1). Thus, our review encompasses a more diverse knowledge pool than Powell’s review (1976), which included fewer references (n = 46). For a list of the references reviewed, see Electronic Supplementary Material (ESM) Table S1.
For each bibliographic reference and herbarium specimen we recorded (when available), the country, island, habitat, elevation, scientific name of the species, plant part used, indigenous group, locality, and the use description. Each plant use was classified into one of ten use categories and subcategories following the Economic Botany Data Collection Standard (F. Cook 1995), with modifications explained in Cámara–Leret et al. (2014): Animal food, human food, construction, culture (“Cultural” in Cámara–Leret et al. 2014), environmental, fuel, medicine (“Medicinal and Veterinary” in Cámara–Leret et al. 2014), toxic, utensils, tools, and other (for a description of subcategories refer to Supplementary Table 1 in Cámara–Leret et al. 2017). Two subcategories were created for uses not classifiable under the subcategories of “toxic” and “environmental”: “other–toxic” and “other–environmental.” Plant parts included the root, young shoot, stem, bark, exudate, leaf sheath, petiole, leaf rachis, cirrus, spear leaf, palm heart, entire leaf, flower, inflorescence, bract, fruit, seed, and entire plant. Unspecified plant parts were classified as “not specified.” Wherever possible, each use report was assigned to one of the New Guinea habitats defined by Paijmans (1976). We followed the Plants of the World Online (http://powo.science.kew.org) to unify nomenclature and classified taxa into native, endemic, and non-native following taxonomic monographs (e.g., Flora Malesiana: https://floramalesiana.org/). We verified indigenous group names using the Ethnologue (www.ethnologue.com) (Simons and Fennig 2018) or Glottolog (http://glottolog.org). Reports that lacked indigenous group names (n = 22,153) were classified as “not specified” and those that could not be matched to an indigenous group (n = 749) as “unresolved.” The geographic location of each indigenous group was recorded from the literature or when coordinates were missing, we first obtained the language ISO–639–3 code from Ethnologue or TransNewGuinea (http://transnewguinea.org) and then matched this code with coordinates available in Glottolog.
We defined a “plant use” for a given species as the use associated to a use category and use subcategory for a specific plant part. We defined a “use report” as the citation of a “plant use” from a bibliographic reference or herbarium specimen. To quantify patterns across New Guinea’s habitats, we analyzed 17,894 use reports with habitat-level information from 224 references and 756 herbarium specimens. To assess the relationship between documentation effort and extinction risk of indigenous groups, we used language endangerment as a proxy of the extinction risk of indigenous groups. We obtained the language endangerment classification from Ethnologue (Simons and Fennig 2018), which uses the Expanded Graded Intergenerational Disruption Scale (EGIDS, Lewis and Simons 2010). Our sample of New Guinea’s languages included eight of the 13 EGIDS levels: wider communication, educational, developing, vigorous, threatened, shifting, moribund, and nearly extinct. Of these, the latter four are considered to comprise the endangered category.
Results and Discussion
Overall, we reviewed 488 references and 854 herbarium specimens, which contained 40,376 use reports on 3434 plant species, 19,948 plant uses, and 217 indigenous groups. The first reports on useful plants date to the 19th century (Miklouho–Maclay 1886), and the number of references and their geographic coverage has significantly increased in the last two decades (Fig. 1). Most studies have been published after Powell’s 1976 review (446 references, 91%) and these contain 38,378 use reports (95% of total). References differed substantially in their quality, with 20 “data-rich” studies containing 53% of all use reports, 66% of plant species, 60% of plant uses, and 18% of all indigenous groups (ESM Table S1). While references contained more use reports than herbarium specimens (30,679 vs. 885), herbarium specimens added 159 species and new localities that were found in references (Fig. 1), illustrating that herbaria are important ethnobotanical repositories (Souza and Hawkins 2017).
Mainland New Guinea—with 442 references, 36,694 use reports, and 3292 species—has been substantially better studied than the next best-studied islands of New Britain, New Ireland, Manus, Fergusson, Biak, and Yapen (Fig. 1). The number of references in Indonesia has increased considerably in the last two decades (Fig. 1) and exceeds that of Papua New Guinea (304 vs. 255), but studies in Indonesia have fewer use reports (12,154 vs. 27,701), plant uses (9083 vs. 17,917), species (1705 vs. 2670), and mean number of use reports per reference (mean ± SD, 38 ± 119 vs. 106 ± 339). Contrasting these results with Ecuador—which has a comparably diverse flora of 17,548 vascular plant species (Ulloa et al. 2017)—we can place research in New Guinea in a global context. Ecuador has more useful species—5172 (De la Torre et al. 2008)—and is the best-studied Neotropical country in taxonomy (Ulloa et al. 2017) and ethnobotany (Cámara–Leret et al. 2014). Given New Guinea’s higher cultural diversity (i.e., > 1100 indigenous groups vs. 13), and its vast area that remains underexplored, we expect that additional research will yield thousands of plant species not yet recorded in the literature.
Our review indicates that lowland tropical forests and lower montane forests have received greater attention and have more references and more useful species and use reports than all other habitats combined (ESM Table S2). These biases may partly result from the fact that under-documented habitats are ecologically marginal environments for human habitation, including alpine areas with extreme temperatures and low fertility soils (Bleeker 1983) and lowland swamp forests with high incidences of malaria (Riley 1983). The most cited plant families in New Guinea were Fabaceae (2355 use reports), Arecaceae (2294 use reports), and Moraceae (2049) (ESM Table S3). Interestingly, these families are also remarkably useful in other wilderness areas like Amazonia (Prance et al. 1987) or the Chocó biodiversity hotspot (Galeano 2000) and deserve special consideration in terms of conservation. Ficus, Pandanus, and Syzygium were the most important genera based on their number of use reports and plant uses (ESM Table S4). Together, these important plant families and genera deserve further attention and represent model groups to investigate cross-cultural patterns in IK.
Multiplicity of Plant Uses
The Multiplicity of Plant Uses Known by New Guinea’s Indigenous Groups.
Blood and cardiovascular system
Cultural diseases and disorders
General ailments with unspecific symptoms
Infections and infestations
Metabolic system and nutrition
Nervous system and mental health
Pregnancy, birth, and puerperal
Reproductive system and sexual health
Skin and subcutaneous tissue
Utensils and tools
Hunting and fishing
Utensils and tools other
Cloth and accessories
New Guinea’s Indigenous Groups
Language underpins peoples’ ability to identify and use plants, but massive socioeconomic transitions are threatening many languages and weakening the links between nature and human societies globally (Karki et al. 2018). We find 217 indigenous groups (19%) have been studied (152 from Papua New Guinea, 87 from Indonesia), but most remain under-documented (mean ± SD use reports, 80 ± 252). There were 160 studies made with a total of 163 non-endangered indigenous groups (wider communication, 5; educational, 9; developing, 113; vigorous, 36) and 64 studies made with 54 endangered groups (threatened, 34; shifting, 12; moribund, 6; nearly extinct, 2). Non-endangered groups have more use reports than endangered groups (15,525 vs. 1949), useful species (1876 vs. 488), and plant uses (7040 vs. 1289), and 90% of the 54 studied endangered indigenous groups have < 100 use reports (ESM Table S8). But even large indigenous groups remain understudied, e.g., the Asmat of Indonesia who number 40,000 and occupy ca. 20,000 km2 have only five use reports. These knowledge gaps would be expected for small indigenous groups of New Guinea’s remote interior ranges, some of which were first contacted by outsiders only in 1930 and 1954 (Leahy 1991; Matthiessen 2003) but are striking in the case of these charismatic widespread coastal indigenous groups.
Our regional synthesis about IK on plant utilization in New Guinea indicates that despite 488 studies have been made over 130 years, most have been fragmentary. As a result, major knowledge gaps exist about how plants are being used in the world’s most bioculturally diverse region. Previous research has emphasized particular ecosystems and has neglected small indigenous groups whose languages (and therefore IK about plants) face extinction risk. Yet given the aim of national governments to preserve the beneficial contributions that nature provides to people and strengthen indigenous peoples’ rights, improved strategies to document and mainstream IK will be necessary. Our identification of important taxa according to IK represents a baseline for the local governments of Indonesia and Papua New Guinea to select charismatic taxa to develop the region’s green economy. Still, further fieldwork will be necessary to address the discrepancy between documentation effort and indigenous groups’ extinction risk.
We thank D. Frodin and the staff at RBG Kew’s Library, Art and Archives Department for the assistance in finding references. We extend our gratitude to L. Green (RBG Kew Digital Collections Unit) and S. Arias (Naturalis Biodiversity Center) for assistance with herbarium databases, K. Willis and T. Ulian (RBG Kew) for support, O. Pérez-Escobar for discussions, and I. Cámara for assistance with the design–layout of figures.
- Arobaya, A. and F. Pattiselanno. 2007. Ethnobotany of Dasigo Tribe of Mamberamo in Papua. Beccariana 9(1):1–4Google Scholar
- Avé, W. 1998. Preliminary list of the use of the plants of Ayawasi. Unpublished ReportGoogle Scholar
- Bau, B. B. and A. D. Poulsen. 2007. Ethnobotanical notes on gingers of the Huon Peninsula in Papua New Guinea. Gardens’ Bulletin Singapore 59:23–34Google Scholar
- Bleeker, P. 1983. Soils of Papua New Guinea. Canberra, Australia: The Commonwealth Scientific and Industrial Research Organization Australia.Google Scholar
- Brummitt, R. K., F. Pando, S. Hollis, and N. A. Brummitt. 2001. World geographical scheme for recording plant distributions. International Working Group on Taxonomic Databases for Plant Sciences (TDWG). London: Royal Botanic Gardens Kew.Google Scholar
- Cook, F. 1995. Economic botany data collection standard. Prepared for the International Working Group on Taxonomic Databases for Plant Sciences (TDWG). London: Royal Botanic Gardens Kew.Google Scholar
- Cook, C. D. 2016. Amuga–gaig–e: The ethnobotany of the Amungme of Papua, Indonesia. Ottawa: Canadian Science Publishing.Google Scholar
- De la Torre, L., H. Navarrete, P. Muriel, M. J. Macía, and H. Balslev. 2008. Enciclopedia de las Plantas Útiles del Ecuador. Quito: Herbario QCA de la Escuela de Ciencias Biológicas de la Pontificia Universidad Católica del Ecuador & Herbario AAU del Departamento de Ciencias Biológicas de la Universidad de Aarhus.Google Scholar
- Dhir, R. K. 2015. Indigenous people in the world of work in Asia and the Pacific. Geneva: International Labour Office.Google Scholar
- FAOSTAT. 2017. Forestry production and trade. www.fao.org/faostat/en/#data/GL. Accessed March 2019
- French, B. R. 1986. Food plants of Papua New Guinea. Privately published. Accessed online: http://papuaweb.org/dlib/bk/french/index.html.
- Garnett, S. T., N. D. Burgess, J. E. Fa, A. Fernández–Llamazares, Z. Molnár, C. J. Robinson, J. E. Watson, K. K. Zander, B. Austin, E. S. Brondizio, and N. F Collier. 2018. A spatial overview of the global importance of Indigenous lands for conservation. Nature Sustainability 1:369CrossRefGoogle Scholar
- Hide, R. 2014a. A preliminary bibliography of ethnobotanical research in West Papua (Indonesia), part I: Publications 2000–2013.Google Scholar
- ———. 2014b. A preliminary bibliography of ethnobotanical research in West Papua (Indonesia), part II: Publications 1963–1999.Google Scholar
- ———. 2015. Supplement #1 to A preliminary bibliography of ethnobotanical research in West Papua (Indonesia), part I: Publications 2000–2013.Google Scholar
- ———. 2016a. Supplement #2 to A preliminary bibliography of ethnobotanical research in West Papua (Indonesia), part I: Publications 2000–2013.Google Scholar
- ———. 2016b. Supplement #3 to A preliminary bibliography of ethnobotanical research in West Papua (Indonesia), part I: Publications 2000–2013.Google Scholar
- ———. 2017. Supplement #4 to A preliminary bibliography of ethnobotanical research in West Papua (Indonesia), Part I: Publications 2000–2013.Google Scholar
- Holdsworth, D. K. 1977. Medicinal plants of Papua New Guinea. South Pacific Commission Technical Paper No. 175. Noumea, New Caldonia: South Pacific Commission.Google Scholar
- Karki, M., S. Senaratna Sellamuttu, S. Okayasu, and W. Suzuki. 2018. The IPBES regional assessment report on biodiversity and ecosystem services for Asia and the Pacific. Bonn: Secretariat of the Intergovernmental Science–Policy Platform on Biodiversity and Ecosystem Services.Google Scholar
- Leahy, M. J. 1991. Explorations into highland New Guinea, 1930–1935. Tuscaloosa, Alabama: University of Alabama Press.Google Scholar
- Lewis, M. P. and G. F Simons. 2010. Assessing endangerment: Expanding Fishman’s GIDS. Revue Roumaine de Linguistique 55:103–120Google Scholar
- Matthiessen, P. 2003. Under the mountain wall. London: Vintage.Google Scholar
- Paijmans, K. 1976. New Guinea vegetation. Canberra: Commonwealth Scientific and Industrial Research Organization in association with the Australian National University Press.Google Scholar
- Powell, J. M. 1976. Ethnobotany. In: New Guinea vegetation, ed., K. Paijmans. Canberra: Commonwealth Scientific and Industrial Research Organization in association with the Australian National University Press.Google Scholar
- Prescott, T., P. Hormot, F. T. Lundy, R. Fang, S. Patrick, R. Cámara–Leret, and R. Kiapranis. 2017. Tropical ulcer plant treatments used by Papua New Guinea’s Apsoko nomads: Fibroblast stimulation, MMP protease inhibition and antibacterial activity. Journal of Ethnopharmacology 205:240–245CrossRefGoogle Scholar
- Saslis–Lagoudakis, C. H., J. A. Hawkins, S. J. Greenhill, C. A. Pendry, M. F. Watson, W. Tuladhar–Douglas, S. R. Baral, and V. Savolainen. 2014. The evolution of traditional knowledge: Environment shapes medicinal plant use in Nepal. Proceedings of the Royal Society B: Biological Sciences 281:20132768CrossRefGoogle Scholar
- Sillitoe, P.. 1995. An ethnobotanical account of the plant resources of the Wola region, Southern Highlands Province, Papua New Guinea. Journal of Ethnobiology 15:201–236Google Scholar
- Simons G. F. and C. D. Fennig. 2018. Ethnologue: Languages of the world, Twenty-first edition. SIL International. http://www.ethnologue.com. Accessed March 2019
- Thiers, B. 2019. Index herbariorum: A global directory of public herbaria and associated staff. New York Botanical Garden’s Virtual Herbarium. http://sweetgum.nybg.org/ih/. Accessed March 2019
- Warburg, O. 1891. Beitrage zur Kenntnis der papuanischen flora. Botanische Jahrbücher fur Systematik, Pflanzengeschichte und Pflanzengeographie 13:230–455Google Scholar
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