Wild harvesting or cultivation of commercial environmental products : A theoretical model and its application to medicinal plants
Abstract
On average, environmental income accounts for more than a quarter of rural household income in tropical and sub-tropical countries. One way to increase incomes from wild-harvested products is cultivation. In a landmark paper, Homma (1992) identified four phases describing the economic dynamics of environmental product cultivation, emphasising product scarcity. We reviewed literature that applied and/or discussed Homma's model. This suggested that additional factors, beyond resource scarcity, induce the transition to cultivation. We propose an alternative model of the dynamics of environmental product cultivation pathways, emphasising stock size, contextual, harvester, and mediating factors. The model has four possible product-level outcomes: scarcity induced cultivation, economic extinction, abundance with cultivation, and continued sole wild harvesting. We investigated this model empirically through the case of commercial medicinal plant harvesting in Nepal, using harvester interviews (n = 362) and published monthly price data for the most commonly traded products (n = 12) during a nine-year period. We found evidence of all four possible product-level outcomes, with “abundance with cultivation” being the most common. This supports that scarcity is not sufficient to explain cultivation processes; harvester decision-making processes and contextual and mediating factors must also be assessed.