TWENTY-FIVE fragments of land that together cover an area smaller than
Greenland contain the remaining habitats for up to a half of all the planet’s
land species, according to a new study of the “hotspots” for biological
diversity. But not everyone agrees that preserving hotspots is the best approach
to conservation.
Conservation scientist Norman Myers of Green College, Oxford, says that
concentrating scarce money to conserve these hotspots “would go far to stem the
mass extinction of species now underway” (Nature, vol 403, p 6772).
But leading biologists and conservationists attacked the strategy, saying
Myers’s methodology is flawed and his conclusions outdated and misguided. “This
kind of approach can be very dangerous because it distorts priorities,” said Tim
Whitmore, a botanist at the University of Cambridge.
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Myers concluded that 44 per cent of all plant species and 35 per cent of land
vertebrates live only within the hotspots, which cover 2.1 millions square
kilometres. He argues that invertebrates—which make up 95 per cent of all
species—are similarly concentrated.
Of his 25 hotspots, 15 are tropical rainforests and nine are islands. They
include the tropical Andes mountains, which contains 8 per cent of the world’s
plants, Madagascar, the Atlantic forests of eastern Brazil, the Philippines and
New Caledonia.
Myers first coined the phrase “biodiversity hotspots” in the 1980s to
describe areas with many endemic species and major threats to their ecosystems.
His latest paper has only fuelled the controversy over whether their protection
should be the backbone of conservation efforts.
He has the backing of Conservation International, a large private charity
that buys up wilderness areas round the world and helped fund Myers’s latest
work. Its president, Russell Mittermeier, is a co-author of the study. The
charity’s website says it has “adopted Myers’s hotspots as the guiding principle
for conservation investment”.
But critics say the approach is scientifically flawed. “You cannot, as he
claims to, predict the richness of one group of species from that of another.
There is often no correlation,” says Whitmore. “Myers is deluding himself if he
thinks he has identified hotspots. We know far too little. Mostly, he has just
identified where people have gone collecting.”
A massive amount of conservation funding has gone on tropical rainforests
because of the hotspot approach. Species living in other habitats, such as
deserts, grassland, tundra and temperate forests have been neglected. That is
why both environmental groups and the World Bank’s Global Environment Facility
have adopted an alternative approach in the 1990s designed to increase the
amount of money spent outside the hotspots, says Whitmore.
This approach identifies and protects the best examples of the widest range
of ecosystems. According to Andrew Lee, deputy director of programmes for the
Worldwide Fund for Nature in Britain, says: “We want to save species from all
types of ecosystems, not those that happen to live in hotspots.”