uu.seUppsala University Publications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
A quantitative market survey of medicinal plants used in Dar-es-Salaam and Tanga.
Show others and affiliations
(English)Manuscript (preprint) (Other academic)
Abstract [en]

Tanzania has a thriving medicinal plant trade, which is solely based on the harvest of wild plant resources. Many of the plants are dried or powdered and often lack sufficient morphological characters for species-level identification. It is thus unclear which species exactly are traded and in what amounts. This study provides an overview of species traded in the main Tanzanian coastal trade hubs Dar-es-Salaam and Tanga, quantifies the annual sales volumes of these plants and gives an overview of the possible conservation issues arising from the wild-harvest of Tanzanian medicinal plants. Based on the interview data from 46 questionnaires an overview was compiled of the plants most frequently mentioned by the market vendors as well as a list with plants that were considered to become more difficult to obtain. A total of >850 single ingredient samples was collected. The main health categories for which these plants are reported to be used are women’s health, ritual purposes and respiratory problems. In addition to vouchers from the plants sold on the market, reference herbarium vouchers were made in the field together with a medicinal plant collector for the twenty most frequently mentioned plants. Results from the field indicate that there are high harvesting pressures on some of the most commonly traded medicinal plant species. The top five plants that are considered to be becoming scarcer are Zanha africana (Radlk.) Exell. (Sapindaceae), Zanthoxylum chalybeum Engl. (Rubiaceae), Warburgia elongata Verdc. (Canellaceae), Allophylus rubifolius (Hochst. ex A.Rich.) Engl. (Sapindaceae) and Cassia abbreviata Oliv. (Leguminosae). Alarmingly, four out of these five plants also figure in the list of most frequently mentioned plants and several vendors indicate they each sell up to 200kg of these species per month. Warburgia elongata is included on the global Red List as endangered, as well as several Zanthoxylum species. From these plants the bark, roots and branches are used for medicine, parts which are often harvested unsustainably. In order to conserve local medicinal plant populations and ensure a sustainable herbal medicine supply, it is essential to look at sustainable harvesting strategies as well as cultivation possibilities in collaboration with the harvesters, middlemen and vendors.

National Category
Other Biological Topics
Identifiers
URN: urn:nbn:se:uu:diva-355180OAI: oai:DiVA.org:uu-355180DiVA, id: diva2:1225439
Available from: 2018-06-27 Created: 2018-06-27 Last updated: 2018-06-27
In thesis
1. Markets, mixtures and molecular methods: Investigating medicinal plant and edible orchid diversity in Tanzania and Zambia
Open this publication in new window or tab >>Markets, mixtures and molecular methods: Investigating medicinal plant and edible orchid diversity in Tanzania and Zambia
2018 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Medicinal plants are an important source of primary healthcare for many people in Tanzania. These medicinal plants are harvested from the wild, and increasing commercial trade poses a serious threat to local plant populations. Currently it is unknown which species are traded and in what amounts. Across the southwestern border in Zambia, the traditional dish chikanda has transformed from a niche product to being a mainstream delicacy. One of the main ingredients are wild-harvested orchids, and these have become depleted throughout the country as an effect of the increased trade. It is unclear which orchid species are targeted and might be at risk of overharvesting. The aims of my doctorate are to map harvest and trade of Tanzanian medicinal plants and Tanzanian and Zambian edible orchids, to investigate whether species that are traded on local markets can be identified using molecular methods such as DNA barcoding and metabarcoding and identify conservation issues arising from wild-harvesting of medicinal plants and edible orchids.

In Paper I DNA metabarcoding analysis of Tanzanian chikanda cake show the presence of 17 different orchids species belonging to the genera DisaSatyrium and Habenaria, and in Paper V the analysis of chikanda tubers sold on Zambian markets reveals that at least 16 orchid species from 6 different orchid genera are targeted in local orchid trade. Paper II describes a quantitative market survey of the non-woody, non-powdered medicinal plants sold on Kariakoo market in Dar-es-Salaam that shows that a total of 67 species are traded in an annual volume of nearly 31 tonnes of fresh and dried medicinal leaves, seeds and fruits with an estimated value of 200,000 USD. For Paper III 873 medicinal plant products were analysed using DNA barcoding, literature and morphology to determine which species are traded on the Dar-es-Salaam and Tanga markets. In total, 509 identifications could be made corresponding to 91 species, 124 genera and 65 plant families, and several cases of over- and under-differentiation were detected. Paper IV builds upon the identifications in Paper III to determine in what amount the medicinal plant species present at the local markets are traded and to investigate if commercial trade poses a threat to local plant populations. It was found that several of the most highly favored medicinal plants were perceived to becoming more difficult to obtain in the wild.

This thesis shows that DNA barcoding is a powerful rapid identification method for morphologically unidentifiable specimens. It also shows that commercialization of wild-harvested plant products threatens local plant populations, and highlights the need for conservation measures to avoid local extinction of economically and socially important plant species.

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis, 2018. p. 36
Series
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, ISSN 1651-6214 ; 1689
Keywords
DNA barcoding, Africa, Species delimitation, Orchids, Medicinal plants
National Category
Other Biological Topics
Identifiers
urn:nbn:se:uu:diva-355182 (URN)978-91-513-0376-5 (ISBN)
Public defence
2018-09-13, Zootissalen, Villavägen 9, Uppsala, 09:00 (English)
Opponent
Supervisors
Available from: 2018-08-22 Created: 2018-06-27 Last updated: 2018-08-28Bibliographically approved

Open Access in DiVA

No full text in DiVA

Other Biological Topics

Search outside of DiVA

GoogleGoogle Scholar

urn-nbn

Altmetric score

urn-nbn
Total: 41 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf