Spotlight on Environmental Buzzwords: Biodiversity Hotspot

Certainly, biodiversity hotspots are worth preserving. But what about 'coldspots' such as Yellowstone National Park? Photo: Amanda Scheliga via Flickr
Aug 2013
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When it comes to global sustainability, one of the biggest challenges is finding a common language. This week, Max McClure puts "Biodiversity Hotspots" in the spotlight. So to speak.

Fourth installment in our series on environmental buzzwords

The world map of red-tinted biodiversity hotspots is by now a familiar sight to conservation students. It's a visually compelling filter through which to view worldwide environmental change, and a major determinant of conservation funding. It's also a controversial simplification that cuts to the heart of the debate over what makes biodiversity important.

"Hotspot" has been used to refer to areas of intense activity since the mid-19th century, and seems to have first been used in a biodiversity context by EO Wilson in 1985. The current list of hotspots, however, is the work of ecologist Norman Myers. Over a series of papers beginning in 1988 and culminating in a 2000 Nature paper, Myers identified 25 global hotspots as "areas featuring exceptional concentrations of endemic species and experiencing exceptional loss of habitat."

Although that number has since been updated to 34, the same basic criteria apply: hotspots must contain at least 0.5% of the earth's plant species as endemics (a species richness criterion), and must have lost 70% or more of its primary vegetation (a threat criterion). The concept's goal is to prioritize conservation funding, and it does this by saving the most possible species in the least possible land. The current list does this admirably, containing 42% of Earth's vertebrate species and 50% of its plant species in only 2.3% of its land surface.

A literature's worth of questions have been raised about how hotspots are best defined. But critics of the biodiversity hotspot concept raise a more fundamental issue: is conserving small areas of high species diversity a desirable conservation goal?

In a 2003 essay entitled "Conserving Biodiversity Coldspots," conservation biologists Peter Kareiva and Michelle Marvier point out that minimizing the amount of land that needs conserving may throw certain conservation objectives under the bus. Tropical ecosystems are disproportionately represented on the list, while even notably diverse temperate ecosystems like Yellowstone National Park don't make the cut. Species with few living relatives are not prioritized over species that come from well-represented taxa. Low-diversity landscapes that provide important ecosystem services, like wetlands, go unmentioned.

The hotspot, then, is an interesting case of a concept that's become the victim of its own success. Myers himself never claimed that it should be the only approach used to direct conservation funding. But as hotspots begin to draw the lion's share of conservation funding, the blind spots they leave need renewed attention.

Comments

Daniel P Faith31 Dec 2013

I like the idea of re-examining current “environmental buzzwords” – popular terms that often are tossed around, with only superficial understanding and explanation. Of course, it can be hard to provide the needed insights and clarifications in a short blog entry. McClure’s short piece, I think, suffers this weakness - it unfairly gives the impression that “biodiversity hotspots” is distracting from other conservation objectives and is relatively over-funded. It would be a shame if Future Earth members/stakeholders/ funders were left with that impression. A more positive, constructive, perspective can be found by correcting some misleading information, and providing some missing information. McClure characterises the hotspots conservation goal as all about “conserving small areas of high species diversity.” This is misleading. In fact, area x could have lower diversity than area y, but gain hotspot status because it has lots of species found no-where else. The sensible way to think about hotspots (as expressed in many papers on hotspots) is that they point to places that are irreplaceable (if we want to conserve global biodiversity) and vulnerable (to biodiversity loss). In this way, hotspots link to fundamental principles of systematic conservation planning (SCP). However, rather than defining a complete set of areas representing biodiversity (as in conventional SCP), hotspots point to those areas that, if lost, would foreclose opportunities to ever conserve some elements of global biodiversity. Continued loss of portions of such hotspots, and, ultimately, loss of all the species restricted to those hotspots, might be thought of as a global biodiversity tipping point. The other advantage found in these links to SCP principles of irreplaceability and vulnerability is that they allow integration of now-standard elements of SCP, including ecosystem services and other needs of society, “opportunity costs” of conservation, and so on. Use of irreplaceability and vulnerability supports the “efficiency” of SCP in balancing different needs of society. Such integration of SCP into biodiversity hotspots and related programs has been an active research area (see e.g. Brooks 2010 chapter on biodiversity hotspots, in the book Conservation Biology for All). While McClure argues that hotspots efforts can mean that places providing important ecosystem services may “go unmentioned”, the more constructive perspective recognises that hotpots fit into a framework that considers multiple goals of conservation. Biodiversity hotspots logically could find a good home in Future Earth programs – they link to global biodiversity tipping points and the idea of risk-averse decision-making. They link local/regional decision-making to global implications. At the same time, they sit in an SCP/sustainability framework, so that decision-making about conservation of hotspots is part of a bigger picture that includes consideration of ecosystem services, costs, social preferences, and other factors.
Dan Faith (co-lead of bioGENESIS)