Patterns of change: The dynamics of medicinal plant trade in far-western Nepal.

ETHNOPHARMACOLOGICAL RELEVANCE: Combined quantitative and qualitative environmental product trade studies, undertaken in the same location over time, are instrumental in identifying plant species with commercial demand and explaining what drives temporal changes. Yet such dynamic studies are rare, including for Himalayan medicinal plants that have been large-scale traded for millennia.

AIM OF THE STUDY: To (i) investigate changes in medicinal plant trade in the past 17 years, and (ii) identify the main factors driving changes, using a study of Darchula District in far-western Nepal.

MATERIALS AND METHODS: Medicinal plant production network data were collected from March to August 2016, for the fiscal year 2014-15, for Darchula District in far-western Nepal through 167 quantitative (58 harvesters, 38 sub-local traders, 25 local traders, 25 central wholesalers, and 21 regional wholesalers), 61 qualitative (15 sub-local traders, 19 local traders, 15 central wholesalers, and 12 regional wholesalers) interviews, and four focus group discussions. Results were compared to previously unpublished similar data for Darchula District for the year 1997-98, using quantitative and qualitative interviews with 10 local traders, 20 central wholesalers, and 53 regional wholesalers. Data analysis was guided by an analytical framework derived from Global Production Network theory. Quantitative data were used to estimate changes in 12 indicators while the qualitative information allowed identification of the factors driving observed changes in the indicators.

RESULTS: The volume of medicinal plants traded from Darchula District in the fiscal year 2014-15 was 401 t with a harvester value of USD 5.5 million, representing a 2.3 fold increase in volume and 17.2 fold increase in value compared to 1997-98. Trade in the two observation years comprised 30 air-dried plant products (from 28 identified species as well as lichens and a mineral substance); 12 products were traded in both periods, while seven disappeared, and 11 new products entered the trade. The number of traders increased from 10 to 63, mainly due to the emergence of a single high value product yarsagumba (Ophiocordyceps sinensis), a fungus-caterpillar complex which alone contributed 85% of total trade value. Over the observed time period, harvesters and traders increased their margins at the cost of central wholesalers, indicating that market changes favoured lower tier actors, eroding the previously identified passive central wholesaler oligopsony in Nepal. Important drivers of market changes are: (i) rising incomes in China and India, expressed through demand for new products and increasing per unit prices for a range of products, (ii) expanding infrastructure (roads and telecommunications) towards and into harvesting sites, reducing transport costs and increasing market efficiency, and (iii) government interventions, causing disappearance of some species from trade. These market changes also led to increased cultivation at lower altitudes, and a sharp increase in the number of processor industries in Nepal.

CONCLUSION: Trade in medicinal plant products in far-western Nepal in the past two decades has increased substantially, doubling in volume and increasing 17 fold in value. There is a backbone of constantly traded species but also species that disappear from trade and new species that enter. Changes favour harvesters and traders at the benefit of central wholesalers whose previous passive oligopsony is disappearing. The three main drivers of change are rising incomes in China and India, expanding infrastructure, and government interventions in Nepal. Commercial medicinal plant resources are a substantial asset that appears to offer opportunities for economic development in far-western Nepal. The trade, however, may pose sustainability threats that are best understood by combining species-level biophysical, trade, and consumer studies.