Need for an Ecological Index

2008-01-05 10:05:42

Rohan Wickramasinghe

The article was published in the Sri Lankan newspaper 'The Island' on the 30th November 2005 after the World Environmental Education Congress (WEEC) held in Milan. Author hopes it could provide a base for a project for senior school children or more senior students to devise an Ecological Index and ‘If nothing else, it could help them in thinking out the issues involved!’ Author supposes that could be a form of environmental education.


There is much discussion in recent years (and, in particular, in environmental and scientific circles) of the ‘biodiversity’ in named regions or localities. For instance, Sri Lanka has been termed one of the ‘biodiversity hotspots’ of the world. This means that it has a large variety of indigenous plant and animal species, e.g. orchids, birds and frogs, within its shores and territorial waters. Many of these are ‘endemic’ or found only in this country. (n.b. Islands frequently have a relatively high proportion of endemic species but that is another story which we will not discuss now.)

One question raised in the course of the deliberations at the recent World Environmental Education Congress (WEEC) held in Turin (see THE ISLAND of the 7th November 2005) related to the term ‘biodiversity’. I noted that I felt that, while this concept of making a tally of indigenous species of plants and animals in a given region or locality is very valuable for some purposes, the term is a little too technical and perhaps unsatisfying for educating the general public, including decision makers, on the importance and urgency of the need for biological conservation. I felt that a sterile discussion on ‘biodiversity’ would not provide any compelling argument for members of the general public to support or get involved in biological conservation.

I would like to propose that a sense of the importance and urgency of the need for biological conservation could be better conveyed by the development of the concept of an ‘Ecological Index’ or ‘EcoIndex’ for each country or region (as necessary). This would in some ways be similar to a ‘cost-of-living index’ and would be revised annually in order to provide information and quantify the state of health of the ecology and environment of the locality under consideration.

Fundamentally, the ‘EcoIndex’ of a given locality would compare the numbers of species of living organisms in the year in question to those known to have existed in a base or reference year (say the year 1950, for argument’s sake). Usually, more species of indigenous plants and animals would have been identified by the year 2005 than were known in 1950. However, many would have been lost in the locality in question by 2005 or passed into extinction (some types of living organisms, e.g. bacteria, would be excluded in calculating an EcoIndex due to practical reasons).

The calculation of an EcoIndex would need to be made according to a prescribed formula, which, ideally, would be standard for all localities to permit comparisons and detection of trends (however, different formulae may prove to be necessary for, for example, terrestrial and aquatic environments to avoid the calculation becoming unwieldy). The elaboration or construction of a formula is not a task which can be accomplished overnight and will need multidisciplinary inputs.

It is envisaged that the use and annual review of a given locality’s EcoIndex would be possible without requiring specialist expertise, once the formula is refined and established (after testing). However, drawing up the formula would need careful thought. For instance, does one merely add up the numbers of all species of plants and animals in a locality or does one factor in increases or decreases in the population of each species (or marker species)? If the first option is selected, the dwindling of the population of elephants in Sri Lanka from 3 000 to one would not be reflected in its EcoIndex! On the other hand, however, determining the population numbers of each species of plant and animal every year could be deemed impracticable. Marker species may need to be decided upon.

The construction of the formula for an EcoIndex could also incorporate various other considerations. For instance, industrial pollution in a given locality could be factored in. WEEC used carbon dioxide emissions as a marker to quantify pollution and this could be a useful example to follow in view of its relevance to Global Warming. In view of the disparities between various countries and localities in terms of land area and population numbers, agreement will need to be arrived at as to whether emissions are to be factored in per square kilometre of territory or per unit of human population.

Other factors, which may be considered in calculating an EcoIndex, include human activities (e.g. land clearing, deforestation), desertification, salinization of soil, frequency of natural disasters attributed to human activities (e.g. some landslides) and incidence of certain health problems, which are related to the state of the environment (e.g. certain cancers, dengue, certain birth defects). Which factors can and should be incorporated into the proposed formula will have to be decided after a careful study of all relevant considerations.

As noted above, the construction of an EcoIndex is not a task which can be accomplished overnight and its operation will also require considerable inputs. However, once in place, it should prove a valuable educational and administrative tool towards ecological protection. Even the process of calculating it each year could help to bring to light developing problems and trends, which may otherwise lie hidden until they are far advanced.

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