Evert Thomas

Comparison of health conditions treated with traditional and biomedical health care in a Quechua community in rural Bolivia

BackgroundThe objective of the present study was to reveal patterns in the treatment of health conditions in a Quechua-speaking community in the Bolivian Andes based on plant use data from traditional healers and patient data from a primary health care (PHC) service, and to demonstrate similarities and differences between the type of illnesses treated with traditional and biomedical health care, respectively.MethodsA secondary analysis of plant use data from semi-structured interviews with eight healers was conducted and diagnostic data was collected from 324 patients in the community PHC service. Health conditions were ranked according to: (A) the percentage of patients in the PHC service diagnosed with these conditions; and (B) the citation frequency of plant use reports to treat these conditions by healers. Healers were also queried about the payment modalities they offer to their patients.ResultsPlant use reports from healers yielded 1166 responses about 181 medicinal plant species, which are used to treat 67 different health conditions, ranging from general symptoms (e.g. fever and body pain), to more specific ailments, such as arthritis, biliary colic and pneumonia. The results show that treatment offered by traditional medicine overlaps with biomedical health care in the case of respiratory infections, wounds and bruises, fever and biliary colic/cholecystitis. Furthermore, traditional health care appears to be complementary to biomedical health care for chronic illnesses, especially arthritis, and for folk illnesses that are particularly relevant within the local cultural context. Payment from patients to healers included flexible, outcome contingent and non-monetary options.ConclusionTraditional medicine in the study area is adaptive because it corresponds well with local patterns of morbidity, health care needs in relation to chronic illnesses, cultural perceptions of health conditions and socio-economic aspects of health care. The quantitative analysis of plant use reports and patient data represents a novel approach to compare the contribution of traditional and biomedical health care to treatment of particular health conditions.

Cultural significance of medicinal plant families and species among Quechua farmers in Apillapampa, Bolivia

ETHNOPHARMACOLOGICAL RELEVANCE Medicinal plant use was investigated in Apillapampa, a community of subsistence farmers located in the semi-arid Bolivian Andes. AIM OF THE STUDY The main objectives were to identify the culturally most significant medicinal plant families and species in Apillapampa. MATERIALS AND METHODS A total of 341 medicinal plant species was inventoried during guided fieldtrips and transect sampling. Data on medicinal uses were obtained from fifteen local Quechua participants, eight of them being traditional healers. RESULTS Contingency table and binomial analyses of medicinal plants used versus the total number of inventoried species per family showed that Solanaceae is significantly overused in traditional medicine, whereas Poaceae is underused. Also plants with a shrubby habitat are significantly overrepresented in the medicinal plant inventory, which most likely relates to their year-round availability to people as compared to most annual plants that disappear in the dry season. Our ranking of medicinal species according to cultural importance is based upon the Quality Use Agreement Value (QUAV) index we developed. This index takes into account (1) the average number of medicinal uses reported for each plant species by participants; (2) the perceived quality of those medicinal uses; and (3) participant consensus. CONCLUSIONS According to the results, the QUAV index provides an easily derived and valid appraisal of a medicinal plants cultural significance.

What works in the field? : a comparison of different interviewing methods in ethnobotany with special reference to the use of photographs

Ethnobotanists use a variety of interview techniques to collect ethnobotanical data. Drawing upon the results from a quantitative ethnobotanical study in five Yuracaré and Trinitario communities in the Bolivian Amazon, the pros and cons of the following methods are evaluated: (1) interviews in situ during transects, walk-in-the-woods, and homegarden sampling; and (2) interviews ex situ with fresh plant material, voucher specimens, or plant photographs as reference tools. Although the systematic use of plant photographs for ethnobotanical interviews is poorly documented in literature, the results show that indigenoùs participants in our study recognize significantly more plant species from photographs than from voucher specimens. It is argued that, especially in remote and isolated study sites, photographs might be advantageous over voucher specimens.

Present Spatial Diversity Patterns of Theobroma cacao L. in the Neotropics Reflect Genetic Differentiation in Pleistocene Refugia Followed by Human-Influenced Dispersal

Cacao (Theobroma cacao L.) is indigenous to the Amazon basin, but is generally believed to have been domesticated in Mesoamerica for the production of chocolate beverage. However, cacao’s distribution of genetic diversity in South America is also likely to reflect pre-Columbian human influences that were superimposed on natural processes of genetic differentiation. Here we present the results of a spatial analysis of the intra-specific diversity of cacao in Latin America, drawing on a dataset of 939 cacao trees genotypically characterized by means of 96 SSR markers. To assess continental diversity patterns we performed grid-based calculations of allelic richness, Shannon diversity and Nei gene diversity, and distinguished different spatially coherent genetic groups by means of cluster analysis. The highest levels of genetic diversity were observed in the Upper Amazon areas from southern Peru to the Ecuadorian Amazon and the border areas between Colombia, Peru and Brazil. On the assumption that the last glaciation (22,000–13,000 BP) had the greatest pre-human impact on the current distribution and diversity of cacao, we modeled the species’ Pleistocene niche suitability and overlaid this with present-day diversity maps. The results suggest that cacao was already widely distributed in the Western Amazon before the onset of glaciation. During glaciations, cacao populations were likely to have been restricted to several refugia where they probably underwent genetic differentiation, resulting in a number of genetic clusters which are representative for, or closest related to, the original wild cacao populations. The analyses also suggested that genetic differentiation and geographical distribution of a number of other clusters seem to have been significantly affected by processes of human management and accompanying genetic bottlenecks. We discuss the implications of these results for future germplasm collection and in situ, on farm and ex situ conservation of cacao.

Indigenous community-based forestry in the Bolivian lowlands: some basic challenges for certification

SUMMARY Indigenous Community Forest Operations (CFOs) that have been certified according to the Principles and Criteria of the Forest Stewardship Council (FSC) face numerous obstacles in their struggle to remain certified and obtain tangible economic benefits. Three basic conditions for successful CFO certification are (i) socio-economic stability, (ii) economic viability, and (iii) community members demonstrating an understanding of the key concepts of the FSC certification process. Based upon fieldwork in four Bolivian CFOs and more than 140 interviews, this paper identifies some of the major constraints on community forestry certification in Bolivia. The findings suggest that the present conditions in the studied CFOs are jeopardizing FSC certification and its ability to yield a positive financial cost-benefit balance in the long term. In contrary to what is generally being assumed by Bolivian FSC experts and stakeholders, this study suggests that the recent tendency to form certified community-company alliances, as an alternative to existing approaches, might not (yet) be able to deliver much direct economic benefits to the communities.

Fast-growing pioneer tree stands as a rapid and effective strategy for bracken elimination in the Neotropics

Summary 1. Large areas of agricultural land around the world are degraded as a consequence of dominance by bracken fern (Pteridium spp.). Tropical production systems based on shifting cultivation and cattle breeding are particularly vulnerable to invasion of this species. In spite of this, effective methods for tropical bracken control are limited. 2. Fast-growing tree species have been used successfully to out-compete aggressively colonizing heliophytes and trigger natural succession. Drawing on a traditional Mayan management technique, we evaluate the potential of the pioneer tree balsa (Ochroma pyramidale) to control Pteridium caudatum in Chiapas, Mexico. We tested different bracken cutting frequencies and balsa propagation methods in a factorial randomized block experiment. Eighteen months later, we quantified bracken biomass under the young balsa canopy. 3. Living bracken rhizome biomass correlated significantly with balsa basal area, leaf litter biomass and understorey light intensity. While bracken rhizomes persisted in control plots, it was completely eradicated in plots with a minimum balsa basal area of 11 m 2 ha � 1 . This threshold value was reached in less than 18 months with any of the tested propagation methods (seed broadcasting, direct sowing or nursery seedlings), on the condition of at least monthly bracken cutting during the first six months. 4. The ability of fast-growing broad-leaved pioneer trees like balsa to quickly out-compete bracken fern offers opportunities for large-scale application in tropical rural areas where economic and technical resources are scarce. 5. Synthesis and applications. Mayan subsistence farmers traditionally use balsa to outcompete invasive weeds, including bracken fern. Here, we highlight the usefulness of this method for quick and effective bracken control in southern Mexico. This approach, in combination with balsa’s short rotation cycle, creates opportunities to rapidly convert bracken land into forest stands with commercial potential, thus providing local income and increasing the likelihood of adoption by rural people. We encourage further research to test the potential of balsa and other fast-growing pioneer trees species for controlling bracken and similar weeds.

Application of Molecular Markers in Spatial Analysis to Optimize In Situ Conservation of Plant Genetic Resources

There is a growing recognition of the need to evaluate the diversity status and trends of plant genetic resources’ use and maintenance in natural populations, farmers’ fields, home gardens and in other in situ settings to prioritize and optimize conservation actions and link these effectively with ex situ preservation approaches. The recent development of new powerful molecular tools that reveal many genome-wide polymorphisms has created novel opportunities for assessing genetic diversity, especially when these markers can be linked to key adaptive traits and are employed in combination with new geo-spatial methods of geographic and environmental analysis. New methods to prioritize varieties, populations and geographic areas for in situ conservation, and to enable monitoring of genetic diversity over time and space, are now available to support in situ germplasm management of annual crop and tree genetic resources. We will discuss concepts and examples of application of molecular markers and spatial analysis to optimize in situ conservation. We present a case study on the distribution and genetic diversity of the underutilized new world fruit tree crop cherimoya (Annona cherimola Mill.) in its Andean distribution range to exemplify the usefulness of combining molecular marker and spatial data to inform in situ conservation decisions.

Ethnomedicinal practices and medicinal plant knowledge of the Yuracarés and Trinitarios from Indigenous Territory and National Park Isiboro-Sécure, Bolivian Amazon

AIM OF THE STUDY We investigated the ethnomedical practices and knowledge of medicinal plant and fungus species of contemporary Yuracaré and Trinitario ethnic groups from Indigenous Territory and National Park Isiboro-Sécure (TIPNIS), located in the Bolivian Amazon region. Our aim was to identify the culturally most significant medicinal plant families, growth forms and species, as well as to assess the current state of knowledge regarding the bioactivity of the most important species, based on available literature data. MATERIALS AND METHODS Medicinal plant and fungus species were inventoried during homegarden and swidden sampling, walk-in-the-woods and transect sampling. Data on medicinal uses were obtained from 12 Yuracaré and 14 Trinitario participants. RESULTS We commence by providing a brief overview of Yuracaré and Trinitario ethnomedical systems, highlighting the important shamanistic component of particularly Trinitario traditional medicine. The rest of the paper is dedicated to an analysis and discussion based on the 349 inventoried medicinal plant and fungus species. Contingency table and binomial analyses of medicinal plants used versus the total number of inventoried species per family showed that several plant families are significantly over (Piperaceae, Araceae, Solanaceae, Asteraceae and Siparunaceae) and underused (Chrysobalanaceae, Sapotaceae, Lauraceae, Celastraceae and Annonaceae) in traditional medicine in TIPNIS. Also herbaceous plants are significantly overrepresented in the medicinal plant inventory, which is in line with relevant literature. Our ranking of medicinal species according to cultural significance is based on the Quality Use Agreement Value (QUAV) index we developed and presented in a previous paper. Results indicate that the QUAV indexs property to mainly select species that combine multiple ethnomedical uses with high informant consensus, justifies its use as a measure of cultural significance of medicinal plants in TIPNIS. Results of a literature search suggest, on the other hand, that the QUAV(s) score of a species could also be indicative of its bioactivity. CONCLUSIONS In addition to the QUAV indexs value as a tool for assessing the cultural significance of medicinal species, it might also be useful to identify species with a higher likeliness of being bioactive.

Plant use and management in homegardens and swiddens: evidence from the Bolivian Amazon

Amazonian plant management is perhaps nowhere as intense as in homegardens and swiddens. A quantitative ethnobotanical study was conducted in Indigenous Territory and National Park Isiboro-Sécure, Bolivia, to investigate plant use and management in homegardens and swiddens by local Yuracaré and Trinitario ethnic groups. Ethnobotanical data of plants were obtained from 11 Yuracaré and 11 Trinitario participants through semistructured interviews. A total of 151 different cultivated or tolerated species was recorded, accounting for 21% of all inventoried plants considered useful to local Yuracarés and Trinitarios. The local use value of managed plants is almost twice that of wild plants. Managed plants score particularly higher than wild plants for medicinal, food and material applications. Most managed plants are herbs, followed by trees and shrubs. Nevertheless, managed trees have significantly higher overall use values than all other life forms. Managed trees tend to be particularly more appreciated as sources of food and materials, whereas herbaceous plants generally have a higher therapeutic value. Our results support observations made in literature that moderately humanized landscapes, and homegardens and swiddens in particular, are an important source of food and healing for forest people. Although people generally start managing plants in homegardens and swiddens because of their perceived usefulness, they are also favourable locations to experiment with the usefulness of (managed or wild) plants prevailing there. This particularly accounts for medicinal plants and it is argued that the use of managed plants in traditional medicine relates to (1) the high intensity of contact with theses species, and (2) their chemical defence strategy. To conclude, a number of policy recommendations are presented.

Conflict in Protected Areas: Who Says Co-Management Does Not Work?

Natural resource-related conflicts can be extremely destructive and undermine environmental protection. Since the 1990s co-management schemes, whereby the management of resources is shared by public and/or private sector stakeholders, have been a main strategy for reducing these conflicts worldwide. Despite initial high hopes, in recent years co-management has been perceived as falling short of expectations. However, systematic assessments of its role in conflict prevention or mitigation are non-existent. Interviews with 584 residents from ten protected areas in Colombia revealed that co-management can be successful in reducing conflict at grassroots level, as long as some critical enabling conditions, such as effective participation in the co-management process, are fulfilled not only on paper but also by praxis. We hope these findings will re-incentivize global efforts to make co-management work in protected areas and other common pool resource contexts, such as fisheries, agriculture, forestry and water management.