Sustainable harvest is increasingly seen to be the most important conservation strategy for most wild-harvested species and their habitats, given their current and potential contributions to local economies and their greater value to harvesters over the long term. The basic idea is that non-destructive harvests and local benefits will maintain population, species and ecosystem diversity.
Besides poverty and the break-down of traditional controls, the major challenges for sustainable wild-collection include: lack of knowledge about sustainable harvest rates and practices, undefined land use rights and lack of legislative and policy guidance.
Lack of information on the wild resource
"The most important ingredient required to achieve a truly sustainable form of resource use is information" (Peters 1994). In reality, resource managers are always confronted with the lack of adequate information about the plants used, their distribution, the genetic diversity of wild populations and relatives and, above all, the annual sustained yield that can be harvested without damaging the populations (Iqbal 1993). Research on the conservation and sustainable use of medicinal plants and their habitats has fallen far behind the demand for this globally important resource. Each species has unique ecological, socio-economic, health and cultural associations that must be understood. Model research approaches are feasible, model solutions are not.
Problems of open access
In many cases, access to the resource is open to everybody, rather than a limited access or private ownership. To make a living, commercial medicinal plant gatherers therefore "mine" rather than manage these resources (Cunningham 1994). Open access schemes to harvestable plant population prevent rational and cautious use and make it difficult to adhere to quotas and closed seasons.
Lack of legislative and policy support for wild harvesting schemes
Information on trade in MAP is scarce and data are rarely collected or published at a national level. Much production and consumption is at subsistence level and as a consequence the economic importance of these activities is largely under-estimated in government decision making regarding rural development, natural resource management planning and in government budget allocations (Vantomme in Anon. 2002a). Therefore, national legislation and policies mostly fail to provide frameworks for a rational and sustainable use of wild resource.
Opportunities for governments to develop legislation to control and monitor harvest and trade of medicinal plant species and to consider conservation and sustainable use of medicinal plants as a priority in establishing protected areas have been greatly enhanced by two recent developments in international legislation: the addition of medicinal plant species to the Convention on International Trade of Endangered Species (CITES) and the entry into force of the CBD (see Appendix 2).