Monday, 10 October 2005

A Letter to Nature

The Letter in Nature (vol 436/18 August 2005) by Orme et al.: "Global hotspots of species richness are not congruent with endemism or threat" demonstrates the proposition that "hotspots" and many of the interpretations of the importance of "biodiversity" are potentially misleading when applied to the implementation of conservation policies for endangered species -- or at least that is the interpretation I inferred.

The paper deals almost exclusively with birds, which are generally accepted as one of the better-studied taxa. However, even these taxa demonstrate the failings of the hotspot concept. A glance at the maps immediately demonstrates one of my fundamental criticisms: all hot spot concepts, as currently used, have an automatic bias towards the tropics. Tundra, steppe, temperate woodlands and all other species-poor habitats are absent from any of the hotspot maps.

In order to understand the relative importance of locations for setting conservation priorities, hotspot concepts need to be allied in some way with the species diversity potential for an area; not treated as an absolute. There is absolutely no point in stating the obvious: almost all of Ecuador is bound to have a greater species diversity than an equivalent area of Patagonian steppe. However, this does not mean that from a conservation point of view a given area in Ecuador is more important than that of the Patagonian steppe, since however much of Ecuador is protected, it will not protect a single species of the Patagonian endemics.

If future researchers wish to develop the hotspot concept into something useful, then they must express data in proportion to the potential, not in absolute numbers. Furthermore, it is also essential to take into account the carrying capacity of a habitat; deserts and other species poor habitats usually need much larger reserves if they are to be effective. And finally the island effect needs to be taken into account when proposing conservation areas.

But meanwhile species continue to become extinct, and of greater interest to the present writer, would be evidence that the modelling and theorising has been subjected to a cost-benefit analysis, and been shown to actually conserve threatened species any better than the hunches of informed biologists and field workers. Huge amounts of money in the form of research grants are expended on developing these models, and even reputable conservation bodies give grants for such purposes, but is it justified? The trouble with most of the scientific models is that they are nearly always based on biology and science. Unfortunately, in the real world, politics and economics are invariably more important. I would far rather buy a piece of forest that is actually on the market and under threat, than spend money on working out which piece of forest has the theoretical greatest number of endemic species. As far as I am concerned the economics are relatively simple: In the US or Europe, it will cost around $100,000 a year to keep a single fairly junior scientist employed on researching these issues. That will buy at least 4000 acres of wilderness. Often enough to save more than one species from extinction, as Bob Ridgely, Nigel Simpson and others have demonstrated in Ecuador.

But this is not to say I am anti-science. It's just that I think conservation money should not normally be used for research -- it's a form of fiddling while Rome burns.

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