Conserving threatened widespread species: a case study using a traditional medicinal plant in Asia

Overharvesting and loss of habitat arising from human activities are the most important threats to plants and animals. Conservation efforts targeting medicinal plant species usually focus on endemic, economic and endangered taxa, typically Plant Species with Extremely Small Populations (PSESP) under high extinction risk. However, comparatively little attention has been focused on traditional medicinal plants with widespread distribution, although some of these species, where the whole plant or the tubers are raw materials for medicines, may be on the edge of local extinction. In this study, we appeal to conservationists to pay close attention to threatened widespread species. To this end, a traditional medicinal plant, Stemona tuberosa, which has a distribution that covers more than ten countries in Asia, is studied in detail. The results suggest that destructive overharvesting of the underground tuberous roots of S. tuberosa is the key threat to this species. In addition, pollination limitation, loss of potential seed dispersers, habitat loss, and a scattered distribution pattern may further reduce the survival chances of S. tuberosa. Through multidisciplinary conservation efforts conducted by researchers and local resident, we witnessed the preliminary recovery of S. tuberosa in locations where it has been reintroduced. We think that threatened widespread species should not be overlooked in the field of conservation. Local participation in natural resource management may help to make resources more relevant locally and hence sustainable in remote regions. We suggest that developing multi-stakeholder coalitions should be encouraged to save threatened medicinal plant species in underdeveloped areas.