Biodiversity and Conservation of Medicinal Plants

Biodiversity and Conservation of Medicinal Plants

The term ‘Biodiversity’ is the short form of Biological diversity, used to convey the total number, variety and variability of living organisms in a given area, whether be it on land, in rivers and fresh water bodies, and the seas or the whole surface of the earth. Biodiversity embraces the whole of life, and includes all the micro-organisms, plants and animals, on earth. Biodiversity also refers to and includes the genes of organisms, the ecosystems they live in and the services they provide to keep the planet healthy. The term ‘biological resources’ denotes those components of biodiversity which maintain the current or potential human uses.

Medicinal plants are now recognised, throughout the world, as an important component of natural resources of the respective countries. For all practical purposes, medicinal plants are no different from the other economically important species, whether occurring in the wild or cultivated. They are subject to the same risks and need the same degree of protection, as the other plant resources. For these reasons, it is essential that the total dimension of biodiversity is understood along with the all the implications, in order to be able to derive the full benefit out of our medicinal plant resources.

THE GENESIS OF A GLOBAL PLAN OF ACTION ON BIODIVERSITY

Biodiversity and related issues are now a serious global concern. An awareness of the issues involved is not really new, though the urgency for action was driven home in stages, as briefed below:

a) UN Conference at Stockholm in June 1972 and the Declaration on the Human Environment;

b) United Nations’ Environment Programme (UNEP) of 1991, setting i) priorities for action for conservation and sustainable use of biodiversity and agenda for scientific and technological research; ii) evaluation of economic implications of conservation of biodiversity and its sustainable use, and evaluation of biological and genetic resources; iii) technology transfer and financial issues; and iv) modalities of a protocol for transfer and handling of any living modified organisms through biotechnology; and

c) The Earth Summit (or UN Conference on Environment and Development) at Rio de Janeiro, June 1992, where the document ‘Agenda 21’, that defined the programme for biodiversity estimation, conservation, sustainable use, involvement of local populations and their interests, etc., was adopted by 178 Governments of the world nations (Anonymous. 1993). This document is organised under 27 Principles and covers all issues concerning biodiversity.

Although the Governments have been a party to the document, action in the respective countries can be taken only when legislative measures, through different Acts of Government, are available. Progress in this regard has been patchy. Nevertheless, there is the much needed awareness of the issues involved.

COMPONENTS OF BIODIVERSITY

Biodiversity is usually classified into three categories that represent three fundamental and related levels of biological organisation: a) Ecosystem Diversity, b) Species Diversity and c) Genetic Diversity.

ECOSYSTEM DIVERSITY

An ecosystem is a natural unit consisting of nonliving (abiotic) and living (biotic) components occurring together in nature, which interact to produce a stable system. A forest, a grassland, a pond, and a desert, are examples of ecosystems. The abiotic component consists of the soil, the water and the air whose physical and chemical properties sustain and/or affect life. The biotic component of an ecosystem is formed of living organisms. Functionally these may be producers, consumers or decomposers or a combination of these. All the components of an ecosystem are subject to variability and in turn alter the composition and nature of the ecosystem.

Ecosystem diversity relates to the variety of habitats, biotic communities and ecological processes in the biosphere as well as the diversity within ecosystems. It is generally concerned with the principal biogeographic regions and habitats.

Ecosystem diversity can be described at the following levels and scales:

a) Functional diversity: the relative abundance of functionally different kinds of organisms;

b) Community diversity: the numerical sizes and spatial distribution of communities of organisms, which is often referred to as patchiness; and

c) Landscape diversity: the diversity of scales of patchiness.

Reid and Miller (1989) suggested six rules of ecosystem dynamics which link environmental changes, biodiversity and ecosystem processes:

i) the number and kinds of species that make up communities and ecosystem; change constantly and continuously;

ii) species diversity increases as the environmental heterogeneity or patchiness of a habitat does, but increasing habitat patchiness does not necessarily result in increased species richness;

iii) habitat patchiness influences not only the composition of species in an ecosystem, but also the interaction among the species;