Traditional knowledge hiding in plain sight – twenty-first century ethnobotany of the Chácobo in Beni, Bolivia

The Chácobo belong to the Panoan linguistic group, which includes about twelve tribes (Chácobo, Pacahuara, Matis, Matses, Yaminahua, Ese Eja and others). At the end of the 1890s, the Chácobo lived as semi–nomadic hunters and cassava and maize cultivators, probably in two groups, one with six families and one with four, in north Bolivia, between Lake Roguagnado and the river Mamore, south of their current territory. During the rubber boom in the early 1900s, they were forced by more aggressive tribes to move north, where rubber tappers, who also brought disease and epidemics to the tribe, threatened them. While other tribes were enslaved to work in rubber stations, the Chácobo managed to avoid most of the outside influences. Their first permanent contact with the outside world occurred only in 1953 with members of the the Tribes Missions, and in 1954 the Bolivian government established an agency about 15 km from the current location of Puerto Limones. The missionary linguist Gilbert Prost arrived in 1955 under the auspices of the Summer Institute of Linguistics (SIL). According to [4] there were four Chácobo groups living between the Benicito and Yata rivers at that time, numbering about 200 people [7]. Prost and his wife continued to live among the Chácobo until 1980. In addition to translating the New Testament into Chácobo, they made some observations on cultural and linguistic practices [3, 4]. In 1964, Prost managed to buy a territory in the north of the Chácobo’s ancestral lands, forming the community of Alto Ivón, and most of the remaining population moved there. In 1965, the Bolivian government finally assigned 43,000 ha of land to the Chácobo, although this area was less than 10% of their original territory. The influence of the SIL caused profound cultural change among the Chácobo, including the reported abandonment of traditional costume and dances in 1969 [4].

The official indigenous organization of the Chácobo (Central Indígena de la Región Amazónica de Bolivia (CIRABO) estimates a current population of the Chácobo community of about 1000 people (350+ adults), with Alto Ivón as the largest settlement. The current territory of the tribe according to CIRABO encompasses 450,000 ha, and is roughly equivalent to the original extent of the tribe’s ancestral lands (Fig. 1). The elevation of the territory is about 200 m, and much of the vegetation can be classified as humid tropical Amazon rainforest. However, the territory encompasses also large tracts of periodically inundated savannas, dominated by Mauritiella armata, and large, drier, savanna areas with forest islands. The average annual temperature is 26.8 °C, with an average annual rainfall of 1560 mm. A distinct dry season lasts from June to November [7]. Today the Chácobo are governed by two indigenous organizations: The Capitanía Mayor Chácobo, closely linked to the evangelists, and the Chácobo– Pacahuara Association, recognized by the Central Indígena de la Región Amazónica de Bolivia (CIRABO), and supported by the Central de Pueblos Indigenas del Beni (CPIB) and the Confederacion de Pueblos Indigenas de Bolivia (CIDOB).

Our project explored the current traditional knowledge (TK) on plant use of the Chácobo and Pacahuara in Beni, Bolivia and had three goals: 1) to discover and document current traditional plant knowledge through interviews and surveys, 2) to inventory the current flora of the region, and 3) to repatriate the acquired knowledge as well as previous data to the community.

After obtaining consent from CIRABO, and before starting fieldwork, we conducted a community meeting in May 2013, involving representatives of all 27 villages in the Chácobo Territory, in order to obtain prior informed consent from all communities. This session included the repatriation of the results of previous studies [45‐47]. In addition, during the project all available material on Chácobo plant use was translated to Spanish and repatriated [48]. The Chácobo community itself choose 12 local counterparts to be trained as ethnobotanical interviewers and plant collectors. In September 2013 we conducted a two–week workshop on ethnobiological methods and plant collection, training the 12 selected counterparts, 10 of which finally acted as interveiwers. Training was conducted directly in the field in the central village of Alto Ivón, and involved theoretical exercises (overview on methodology of interviews, collection and herbarium techniques), as well as extensive practical exercises (structuring and testing of questionnaires, test interviews among the participants, field interviews with local community members, plant collection in the field, preparation of herbarium specimens, plant and artifact collection in the local community, data–basing, and initial data analysis).

From November 2013 to May 2015, Chácobo interviewers collected ethnobotanical information from 301 Chácobo participants (150 women, 151 men, representing almost the entire adult Chácobo population), and over 1500 plant samples were collected. Prior to starting the interviews, every interviewer obtained prior oral informed consent from each participant. Chácobo participants were divided into five age classes (18–30 years old: 58 men, 52 women; 31–40 years old: 31 men, 36 women; 41–50 years old: 35 men, 36 women; 51–60 years old: 15 men, 7 women; and >60 years old: 12 men, 19 women). Because the study attempted to interview the whole adult Chácobo population, there was originally no emphasis on achieving a balanced age or gender distribution. All interviews were conducted at the homes of the participants by asking participants to freelist their plant knowledge following [49]. All plant uses were categorized following [49]. All interviews were preferably conducted in Chácobo. In a few cases where participants were not fully fluent in Chácobo, interviewers used Spanish as common language. The plant material was collected under permission from the Ministry of Environment and Water of the Plurinational State of Bolivia, and was identified and deposited at the National Herbarium of Bolivia (LPB) under the collection numbers of the Chácobo collectors. Nomenclature follows www.​TROPICOS.​org. Use descriptions were coded after the fact into subcategories and, for some analyses, into six major categories: fodder, fuel, medical, cultural, construction, tool, and food.

All work was carried out following the International Society for Ethnobiology Code of Ethics [50], and under the framework provided by the Nagoya Protocol on Access to Genetic Resources and Fair and equitable sharing of benefits arising from their use of the Convention on Biological Diversity, the Chácobo community retains the copyright of the traditional knowledge of all informants. Any commercial use of any of the information requires prior consensus with informants and communities, and an agreement on the distribution of benefits.

The total number of unique species reported and unique uses reported for each use category were compared across communities, genders, and age groups (16–30, 31–40, 41–50, 51–60, and 61–82) for 292 informants (dropping for this analysis 8 informants for whom age was not indicated).

To gain a more nuanced look at how these qualities affected not only the number of reports but which species or uses were reported, we ordered informants using non–metric multi–dimensional scaling on distance matrices for plants and uses, and tested how well vectors (age) and factors (gender, ethnicity, community) fit the location of informants in the ordination, using the R package vegan [51]. We used similar methods with plant family fit onto an ordination from distance matrices of plant–use combinations to test whether plant family explains the uses to which plants are put.

We used Indicator Value [52], as implemented in the R package labdsv [53] to combine occurrence frequency and mean abundance of species and uses to elucidate species and uses that had higher fidelity to and/or relative abundance in certain age groups or genders. For this analysis, the P value is the probability of finding an equally high indicator value in random permutations. Species with significantly high indicator values had higher fidelity and relative abundance in certain age groups / genders (were ‘indicators’). We further compared age and gender groups by informant consensus factor (ICF) for each use category, calculated as the number of use reports minus the number of taxa over the number of use reports minus one: (Nur − Nt)/(Nur − 1). We also measured consensus on species uses by quantifying what proportion of each species’ mentions fall within a specific use category.

Plant species and plant family importance was ranked by four metrics: Community and Informant Cultural Importance (CIcom/CIinf) — the sum within species across all plant–uses of the number of informants (for CIinf) or communities (for CIcom) reporting a plant–use over the number of informants/communities reporting the plant; Diversity of Uses (Du) — the Shannon Index of uses [51]; and Use Value (UV), the number of reports of a species over total number of informants asked in a region [54].

To test whether greater knowledge of Chácobo language was associated with a more similar set of knowledge and / or a larger knowledge set of plants and uses, we used the ordination based on uses to examine whether interviewees who reported more Chácobo names tended to report a more similar set of uses, and used linear regression to test whether the number of Chácobo names reported was significantly greater for those who reported more species or more uses.

Despite the similarities among communities in total species and uses reported, we found that informant community significantly influenced both which plants and which uses individual informants reported (Table 2 a&b). In contrast, and in accord with the results above, age and gender did not significantly influence either. Ethnicity of the participants influenced which plant species they used, but did not explain what they were used for. Given the very low r² values, it is clear that much variety in uses was not explained by any demographic and environmental variables explored (Table 2 a&b). In the ordination, we can see this effect more clearly: although there was much overlap, the communities clearly structure which plants were reported. This difference was however much driven by the reports Nueva Unión (Fig. 5).

While age did not in itself explain the ordination well, we did find certain plants to be associated with age categories. In this we found no indicator plants or uses among the first three age groups (16–30, 31–40, 41–50), which suggests to some extent that plants and uses reported by these groups are less distinct than that of the second two age groups (51–60, >60). The 51–60 age group was associated with by Styrax sp., Iryanthera juruensis, Xylopia ligustrifolia, Hirtella pilosissima, Inga sp. 1, and Piper nigrispicum, while the >60 group was indicated by Gustavia hexapetala, Astrocaryum aculeatum, Phenakospermum guianensis, Attalea phalerata, Apuleia leiocarpa, Bixa orellana, Hancornia speciosa, Zingiber officinale, and Eriotheca sp. Likewise, the use subcategory Firewood was associated with the 51–60 age group while the medicinal use subcategories: Skin and subcutaneous tissue, Sensory system, Respiratory system and Musculo–skeletal system all were associated with the >60 age group.

Likewise, although gender did not fit to the overall ordinations, there was a large number of plants associated with female, and a much smaller one with male respondents (Table 3).

Interestingly, all indicator uses were exclusively associated with women (Table 4).

Looking at specific use categories we found broadly similar trends across age categories and genders: tool, construction and food uses usually had the most use reports. We found a lower number of medicinal use reports, although the same number of respondents reported medicinal uses. Food uses consistently had less ICF than tool and construction uses, and medicinal uses even less. Cultural uses, while often reported by fewer informants and with fewer uses, show disproportionately high ICF (Table 5).

Plant relative importance metrics did show a different picture underlining the problems of using diversity indices. The Cultural Importance Index yielded wildly different species sets for Community and Individuals, and both Use Value Index and Use–diversity Index again yielded different sets as species as most important (Table 6).

Because the Cultural Importance Index tends to prioritize species with few informants, we highlighted the species that had both high index values in general, and also a large number of reports to elucidate species that were of high importance in all indices. As result, Vismia macrophylla, Xylopia peruviana, Attalea phalerata, Gossypium barbadense, Attalea maripa and Phenakospermum guianensis were elucidated as the most important species in the daily life of the Chácobo community (Fig. 6). Overall, however, informant consensus was very high in across all age groups and across all use categories (Fig. 7). Arecaceae, Fabaceae, Malvaceae and Rubiaceae were found to be the most important plant families used across most indices, although Moraceae did yield a higher ranking in Use Value (Table 7).

Results also indicated that qualities of plants did to a certain extent explain which uses they were put to. A large number of plant families had specifically Medicinal uses, while other sets of plant families were specifically used for Food, Utensils and tools, and Construction. Not surprisingly, data also revealed that plant families with high importance in all indices calculated (Arecaceae, Fabaceae, Malvaceae and Rubiaceae) had uses in all categories (Fig. 8).

Different use categories also had different levels of fidelity in the species that were reported for them. For instance, relatively few mentions in the construction and tool categories were of species that are uniquely associated with those categories. In contrast, a much greater proportion of mentions for medical uses were of species that were only used for medical uses. This pattern was also true of food plants (Fig. 9).

Interviewees who reported more Chácobo names did indeed tend to report more similar sets of knowledge, and knew more species and uses (Fig. 10). In addition, the number of plants or number of uses reported strongly increased with the number of Chácobo names participants knew (Fig. 11). Although in some degree this was a feature of the study (there was no way to informants to report more names than species), it was clear that very few of those participants with great knowledge of species or uses failed to report a large number of Chácobo names.