Sir: Richard Dowden spoils his careful exploration of the difficulties of protecting unique tropical forests while encouraging economic development in a deprived region ("Madagascar must choose between trees and titanium", 25 January), with the conclusion that "with the right mandate", the company concerned, Rio Tinto Zinc, can "have its mine, restore the forest and reverse the spiral of the people's poverty ...and still make a profit". If only it were true.

Mr Dowden states that the threatened forests can be "replanted" or "restored": the implication being that what is unique can easily be replaced. Sadly, this is impossible.

RTZ proposes to replant with commercial non-native species such as eucalyptus or pine. While plantations can meet timber needs, and thus relieve cutting by destitute local people, such barren monocultures cannot support the rare plant and animal life only supported by the original ecosystem.

There are also real doubts if plantations can even be established. Planting trials in the region, on typical mining land residues, have been extremely disappointing, producing sparse and stunted growth of little productive value.

As to restoration of the original forest, titanium mining involves washing all organic matter from the soil. Consequently, fungi and microflora, essential for forest plant growth in the inherently nutrient-poor substrata, are also rinsed away - no microbugs, no regeneration. Even if, by some still to be explained ecological miracle, native species could take root, the forest would need many centuries to re-establish its diverse wildlife.

Work for 500 people from the mine sounds a reasonable injection of wealth into the local economy. In fact, only 350 low-paid, mostly menial labouring jobs will result. These bear no comparison to the economic independence and significantly higher incomesavailable to a far higher number of local people who could be involved in developing eco-tourism - an industry dependent on preserving the irreplaceable forests and preventing mine pollution of nearby beautiful lagoons and marine environment.

It is finally worth remembering that the forests to be destroyed by the proposed mine contain ancestral tombs and sacred sites of the local Malagasy. RTZ has never publicly explained how these will be protected, or restored when the company packs its bags and leaves for another part of the world.

Conflicts between environmental, economic and social needs can be resolved by appropriate development schemes, such as eco-tourism. Or even by moving the mine site further up the coast where there are similar deposits but no such precious ecosystems survive.

Yours sincerely, CHARLES SECRETT Director PAUL HELLYER Colleague of Andrew Lees in Madagascar Friends of the Earth London, N1

27 January