Conservation: a wider vision

A new method to conserve biodiversity views the problem from the point of view of an entire landscape instead of a single species

Published: Saturday 15 June 1996

-- (Credit: Vishwajyoti)FOR most lay persons, the conservation of biodiversity is a concept that remains confined to the realm of forests. It is a subject which leaves their day to day existence untouched. But as Australian ecologist Robert Lambeck suggests, this disinterest will end if conservationists change their way of thinking (Science, Vol 271, No 5255).

Lambeck works for the Wildlife and Ecology Division at the Commonwealth Scientific and Industrial Research Organisation (CSIRO) in Western Australia. He feels that ecologists should consider a number of 'focal' species which would help define the characteristics of a landscape, rather than concentrating on protecting a single species, say the spotted owl in North America or the Australian Numbat, a banded ant-eater.

The rural landscape of Australia predominantly comprises patches of cropland and pastures, which could support a large number of floral and faunal species. Therefore, the land is dear to both farmers and conservationists. Since most of the cropland is privately-owned, farmers will not undertake serious measures to preserve the biodiversity of their lands unless they are offered sufficient incentives. Lambeck's concerns stem from the fact that 30 per cent of the local mammalian species have become extinct; half the bird population is on the decline and around 24 plant species have totally vanished from an area largely dominated by wheat fields, in southwestern Australia. An added reason for Lambeck's interest is the fact that he happens to belong to the area.

According to Lambeck,a field survey of existing species, and others likely to enter the region, should be conducted right at the start of the conservation programme. The species enlisted by the surveyors is then revieNyqd by experts, who eliminate those species of plants and animals, whose survival is not threatened. The vulnerable ones are placed in sub-groups, depending on the management strategies required to protect them. Some species like the plant called acorn banksia - need minimal protection- requiring only fencing to exclude cattle from browsing. But there are others, like the yellow robin, whose preservation would demand drastic changes in the landscape itself.

The species which require maximum attention are used to identify the critical elements of the landscape. Such species are presumed to be able to define certain features of the area they inhabit, mainly because these very factors hamper their existence. The factors are: the area occupied by them, their movement within that and the availability of resources therein. For example, the species that requires the largest area becomes the 'focal' species and demarcates the land required to design the landscape. Similarly, those with the least mobility will help decide the character of sub areas within the landscape and even provide clues as to how these various patches could be connected. Even the absence of certain species would indicate which native species should be re-introduced into the region.

David Goldney, an ecologist from the Charles Stuart University at Bathurst in New South Wales, Australia, says, "The main value of his (Lambeck's) model is that it helps break the single-species mindset of the "Australian ecologist."

But not all scientists are confident about the feasibility of this model, which at present is only a theory, "He is taking a snapshot," says Steve Falconer, project officer for Rural Nature Conservation of the World Wide Fund for Nature, New South Wales. "I question whether it takes enough into consideration to ensure long-term viability of the ecosystem", Falconer contends.. its critics aJso contend that the model doe4 inot take into account the occurrence of climatic changes. Finally, it is also alleged that Lambeck's model is not practical from the fiscal point of view. Conservationists are concerned about the lack of finances in Australia to sponsor such largescale projects, such as buying land for habitat preserves. Nor have farmers been promised any tax deductions for setting aside land for conservation.

But Lambeck defends the project by saying that farmers have shown interest in his plans as long as they do not threaten them in any manner. For instance, on the large wheat farms where Lambeck has been conducting his studies, the land suffers from salinity due to the high watertables of the area. To lower the watertables, farmers could contribute some marginal land for the propagation of exotic trees or native vegetation, or even both, instead of wheat. Denis Saunders, a CS[Ro ecologist says that such an approach would prove that preservation and profits are not mutually exclusive. Therefore, not all hope is lost. Says Saunders, "We are now trying to integrate Lambeck's model with existing strategies so that farm production and wildlife conservation can both benefit."

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