Trade of wild-harvested medicinal plant species in local markets of Tanzania and its implications for conservation

In Tanzania, approximately 10% of the reported 12,000 species of higher plants are estimated to be used as medicine for treating different human health problems. Most of the medicinal plants are collected from wild populations, but their trade and quantities are not properly recorded. Monitoring of trade in wild-harvested medicinal plants is challenging due to the informal nature of the trade and the fact that most materials are traded in various processed forms. The study aimed to assess the trade of wild-harvested medicinal plant species in local markets of Tanzania and its implications for conservation. Semi-structured interviews were conducted with 40 vendors in Arusha, Dodoma, Mbeya, Morogoro, and Mwanza regions to document frequency, trade chain, and quantity of wild-harvested medicinal plants. The research goals were explained before conducting interviews, and free and prior informed consent was obtained from the participants. Information on marketed medicinal plants, their names and uses, their origin and harvest areas, trade amount per year, most popular medicinal plant species, and their perceived availability by vendors were recorded. The study found that the most frequently traded species were Zanthoxylum chalybaeum Engl., Albizia anthelmintica Brongn., Zanha africana (Radlk.) Exell, Warburgia stuhlmannii, and Vachellia nilotica (L.) P.J.H.Hurter & Mabb. The most popular medicinal plants in the markets are connected to local health problems, including malaria, libido disorders, or infertility. The high diversity of commercialized plants used for medicinal issues mainly relies on wild stock for local consumption and international trade, and this has significant implications for conservation concerns. The study also found that the volume of trade in wild-harvested medicinal plants is substantial, with plant parts such as roots, bark, and leaves being traded in large quantities. The largest volume of trade was in roots, with 3818 kg traded, followed by bark with 1163 kg, and leaves with 492 kg. The study highlights the need for comprehensive monitoring of trade in wild-harvested medicinal plants to address sustainability and conservation issues. The study was conducted in five districts in Tanzania, including Arusha, Morogoro, Mbeya, Mwanza, and Dodoma. These areas were selected according to their greatest market chain information and ecological diversity of medicinal plants. The study used semi-structured interviews with vendors to document frequency, trade chain, and quantity of wild-harvested medicinal plants. The research team also collected voucher specimens of traded medicinal plants to identify the species and their origin. The study's findings have significant implications for conservation and sustainability of wild-harvested medicinal plant species in Tanzania. The study highlights the need for comprehensive monitoring of trade in wild-harvested medicinal plants to address sustainability and conservation issues. The study also emphasizes the importance of proper identification of medicinal plants in the markets with the help of voucher specimens to ensure accurate monitoring of trade.