Thursday, February 15, 2007
A couple of articles caught my eye recently. One in Nature argues that phylogenetic diversity (a measure of how distantly species are related) should be considered in addition to using number of species to identify "hotspots" that deserve priority in conservation efforts. [see Science news report below]. Another Nature article described rapid biodiversity assessments, conflicting ideas on how to set biodiversity conservation priorities, and the utility of these assessments in priority setting [see excerpt below].
Saving Species With Potential [edited by ELP]
By Robert Koenig
ScienceNOW Daily News
14 February 2007
When seeking to preserve biodiversity, simply trying to count and protect every species may not be enough. A new study suggests that conservationists should also consider the extent to which the mix of species in an area has the genetic potential to adapt to change. In the past, many scientists assumed that the number of species in a region reflects that area's potential for evolutionary change. That potential is expressed in terms of "phylogenetic diversity"--a measure of how distantly related those species are. The higher the species number, the prevailing theory went, the higher the phylogenetic diversity, and the easier it would be for the area as a whole to adapt to global change. However, in examining plant life in two biodiversity hot spots in South Africa's Cape region, researchers found that species number and phylogenetic diversity don't always go hand in hand. The researchers found that the western Cape had more plant species and the eastern Cape's flora had higher phylogenetic diversity. That diversity, in turn, had produced more plants with traits useful for food or medicine. [The results] may help conservationists better decide which areas to protect: "A planner might ask, 'Where do I place my next reserve to capture the most evolutionary potential?' It is precisely in these circumstances that one would expect phylogenetic diversity to really come into its own." Another evolutionary genomics researcher agrees that phylogenetics should be used by conservationists, but he cautions that predicting evolutionary change is tricky, as some lineages take millions of years to evolve significantly, while others evolve in much faster.<>>
Rapid biodiversity assessments and conservation priority setting:
The idea is simple. With funds, expertise and time too limited to
conduct thorough species surveys of every unknown region, experts
instead target the most promising areas and quickly assess whether they
are worthy of conservation. Proponents admit that the resulting data
are incomplete, but say the compromise is justified because rough
estimates of biodiversity can help inform preservation decisions. And
even a quick survey by scientists with decades of broad experience in
the field and in museum collections can lead to qualitative estimates
of an area's relative conservation value. "We would all love to spend
more time," says Debra Moskovits, a tropical biologist at the museum
and founder of its RBI initiative. "But the time pressure is intense.
If we can protect some of these areas, then maybe people will be able
to do the more extensive studies the areas deserve."
The protected areas on a list maintained by the United Nations have grown to some 11.5% of the planet's land surface in recent years1, but 'gap analysis' studies show that large numbers of species are not represented in the existing network2. Conservationists have argued for decades about how best to prioritize areas for future conservation: whether by geographical location and political expediency, or through some measure of species numbers, degrees of species interconnectedness, or the presence of rare, threatened or keystone organisms.
The Field Museum team has focused its attention on the high-biodiversity upper Amazon and Andean foothills regions of Ecuador, Peru and Bolivia. Working with local, regional and international scientists and conservation groups, members of the core group of five museum biologists have conducted 12 rapid inventories in these regions since 1999, representing 9.2 million hectares of surveyed land - an area about the size of the US state of Maine. Preliminary results are shared immediately with local communities, organizations and political leaders; formal reports are usually published in a matter of months. "People are making land-use decisions all the time, and they can't protect places if they don't know anything about them," says Corine Vriesendorp, a conservation ecologist and the Field Museum's director for rapid inventories. "If you bring in a crack team of biologists, you can very quickly tell decision makers whether a place is special or not." And it can be done relatively inexpensively - a typical, foundation-funded RBI costs about US$300,000 from initial planning through to the final published report.
Six new protected areas have already been established, comprising about half of the territory the team has surveyed. Most of the remaining land is also on the road to legal protection.
The survey information can also help local communities and governments prioritize specific zones within a surveyed area, identifying those that most urgently need full protection, and those that might be allocated for uses such as tourism and sustainable harvesting. "People overlook the impact that these kinds of survey can have on building local capacity for conservation," notes tropical land use specialist Arturo Sanchez-Azofeifa of the University of Alberta in Canada, who is not involved in the programme. "You can get local participation and a broader perspective, and that really helps build expertise and interest in the local communities."
For the Field Museum team, that means working with local scientists and graduate students to compile the inventories, and forming links with indigenous groups, regional and national governments, and local conservation organizations. The biological work is paralleled by 'social inventories' - surveys of the organizational structure and natural resource use of local villages. That social aspect, says Vriesendorp, sets RBIs apart from other rapid conservation assessments and is crucial to their success. "The dream is to protect these areas indefinitely," she says, "and that can only happen if the local people and their leaders are fully engaged."
The core of the RBI approach is the rapid inventory itself. The surveys have their roots in a 1987 birding trip, when physicist and avid birder Murray Gell-Mann and ornithologist Ted Parker first started talking about using quick-time biological surveys to spur conservation. By 1990, environmental group Conservation International, based in Washington DC, had put their ideas into practise; Moskovits and other Field Museum team members, including botanist Robin Foster and ornithologists Doug Stotz and Tom Schulenberg, were all early participants. The idea caught on with other groups, and by 1995 the Field Museum had initiated its own rapid inventory programme, spearheaded by Moskovits.
Each inventory starts with satellite images, geological maps and, if possible, video footage taken from the air. Experience has taught that the taxonomists' time is better spent walking trails than wielding machetes to create them. The RBI scientists identify areas they think will give them a broad cross-section of the available habitats, and advance teams of local workers prepare bush camps and cut trails to their specifications.
We're looking at what's common, what's rare, what's dominant and what's really weird.
In Sierra del Divisor, that means three separate campsites: two at higher elevations, one along a lowland riverbank, and each with a network of trails stretching for dozens of kilometres along streams, through swamps and up mountains. The museum biologists are joined by nine scientists and students from Peru and Brazil. "We try to balance the teams to get broad experience across the region, as well as local expertise," Vriesendorp says. The inventory focuses on limited taxa - trees, shrubs, mammals, birds, fish, reptiles and amphibians - to keep the workload manageable, and seeks to determine "what's common, what's rare, what's dominant and what's really weird", says Vriesendorp. The scientists tabulate individual species of plant and animal, and draw on experience to gauge the relative health, uniqueness and diversity of each ecosystem. The social inventory team, meanwhile, conducts its own surveys to map out the location and structure of local human populations, including the potential for and threats to long-term conservation.