Medicinal plants are living resource, exhaustible if overused and sustainable if used with care and wisdom. Their sustainability is essential to sustain one of world's oldest medical traditions, a priceless legacy of the Indians. Millions of rural households still use medicinal plants in a self-help mode. Over one and a half million practitioners of the Indian systems of medicine, in the oral and codified streams, use medicinal plants in preventive, promotive and curative applications.

There are estimated to be over 8000 herbal product-manufacturing units in India with a combined annual turnover of over Rs.4000 crores/year.  In recent years, the growing demand for herbal products has led to a quantum jump in volumes of plant material traded within and across countries.  Conservative estimates put the economic value of medicinal plant related International trade to be of the order of US $ 880 million and this is growing. 

While the demand for medicinal plants is increasing, their survival in their natural habitats is under growing threat. Several medicinal plants have been assessed as endangered, vulnerable and threatened due to over harvesting in the wild. Rapid loss and fragmentation of natural habitats is an added danger. Species like Coscinium fenestratum, Janakia arayalpathra, Dactylorhiza hatagirea, Saussurea costus are critically endangered in the wild. It is expected that around a 1000 species of medicinal plants are facing threat to their existence in the wild and some of them like Plectranthus vettiveroides have become extinct. For meeting the future needs cultivation of medicinal plant has to be encouraged.

Medicinal plants are potential renewable natural resources.  Therefore, the conservation and sustainable utilisation of medicinal plants must necessarily involve a long-term programme. A holistic and systematic approach envisaging interaction between social, economic and ecological systems will be a more desirable one.  The most widely accepted scientific technologies of biodiversity conservation are the in-situ conservation and cultivation methods.

The best and cost-effective way of protecting biological and genetic diversity is the 'in-situ' or on the site conservation wherein a wild species or stock of a biological community is protected and preserved in its natural habitat.  The prospect of such an 'ecocentric', rather than a species centred approach is that it will prevent species from becoming endangered by human activities and reduce the need for human intervention to prevent premature extinctions.  Establishment of biosphere reserves, national parks, wild life sanctuaries, sacred groves and other protected areas forms examples of 'in-situ' methods of conservation. In situ conservation thus serves the purpose of long term survival and evolution of a species, in association with other plant, animal & microbial associates in the Eco-system.

The term 'cultivation' generally implies selection of a particular variety of a species and large-scale multiplication of that particular variety to meet the requirements of consumption.  The intention behind cultivation is consumption. Though some highly productive or high quality individuals may be chosen for providing large-scale propagation material, the progeny used in cultivation is expected to have narrow genetic variation.  It is likely to be more susceptible to pests and diseases than natural populations. 

Thus, in situ conservation and cultivation serve entirely different purposes although both are important and relevant in their respective contexts. While cultivation can reduce pressure on the wild populations, it cannot replace them. The wild populations need to be preferably conserved as gene pools, rather than be used as raw material for consumption.

Role of In situ conservation:

It is only in their natural habitats (in situ) that breeding populations of plants can survive so as to evolve.  Even if we put a particular variety of a particular species under millions of hectares of cultivation, the species can still go extinct in the wild, leading to loss of certain strains or genes absent in the cultivated stock. Therefore, no cultivation strategy can ever ensure the survival of species.  In fact, in order to sustain a viable cultivation programme, it is essential to maintain the intra-specific diversity or the germplasm of species because it is the germplasm, which provides opportunities for selecting a desired variety or for breeding a new one.  The ideal way to maintain the intra-specific variation within the species is the way nature does it i.e. through an in situ conservation strategy.  This is the healthiest and most cost-effective way to maintain germplasm of a species, as other ex situ conservation measures such as cryopreservation i.e., deep refrigeration requires prohibitively high costs and human skills. In situ conservation is also the only way to ensure long-term survival of the medicinal plants diversity of a region.