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NEWS TIPS FROM THE August 2004 ISSUE OF CONSERVATION BIOLOGY the Journal of the Society for Conservation Biology
FOR IMMEDIATE RELEASEPlease mention Conservation Biology as the source of these items:
PDFs of these papers are available to the media through August; please register for the Society for Conservation Biology's media services at: http://conbio.org/SCB/Information/Media/ Images are provided by the researchers; please contact them directly for more information. For more information about the Society for Conservation Biology: http://conservationbiology.org
18th ANNUAL MEETING, SOCIETY FOR CONSERVATION BIOLOGYJuly 30-August 2, 2004, New York City
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| A juvenile snapping turtle attempting to
cross a heavy duty highway while migrating between ponds in the central
Adirondack region of New York, USA |
Anyone who's seen a turtle cross the road knows that these slow-moving reptiles are no match for the cars whizzing past. But there has been little evidence that roads are a threat to turtle populations. Now new research suggests that cars are picking off the females: painted turtle populations are 73% male and snapping turtle populations are 95% male near roads in upstate New York.
"Our study indicates that females may be taking the brunt of the road kill," says James Gibbs, who presents this work with David Steen in the August 2004 Conservation Biology. Both researchers are at State University New York, Syracuse; Steen will be at the Joseph W. Jones Ecological Research Center in Georgia beginning in August.
The U.S. has about a fifth of the world's turtle species (about 56 out of 257) and nearly half of them are imperiled. Roads are a likely threat to turtles because the juveniles migrate to find new places to live, and the adults migrate to find mates and nest sites. However, linking roads to declining turtle populations has been difficult because much of the road expansion has been relatively recent and turtles can live for more than 40 years, which means that even disturbed populations could persist for decades.
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co-author Dave Steen with a large female snapping turtle. Females are disproportionately impacted by roads. |
Steen and Gibbs compared the sex ratios of painted and snapping turtle populations in 35 wetlands in areas with high and low road densities near Syracuse, New York. Most of the high road density study sites were near the New York State Thruway and Interstate 84, while the low road density study sites were in protected areas including Howland Island Wildlife Management Area and Three Rivers Wildlife Management Area.
The researchers found that "high road density" turtle populations had many more males than "low road density" populations: painted turtles were 73% vs. 54% male, respectively, and snapping turtles were 95% vs. 74% male, respectively. This suggests that more females are killed on roads, presumably during their spring-summer nesting migrations. Fewer female turtles could mean fewer baby turtles to replenish the populations.
Turtles can be protected from traffic near wetlands by installing culverts to help them cross roads and short fences to keep them from crossing roads. People can also help turtles by moving them off roads. "When you see a turtle crossing a road in the spring or summer, there's a good chance it is a female full of eggs, so don't hit it and don't take it home or relocate it miles away," says Gibbs. Instead, turtles should be put on the side of the road they were trying to reach.
CONTACT:
David Steen: 845-699-2547, DavidASteen@yahoo.com
James Gibbs: 315-470-6764, jpgibbs@syr.edu
(NOTE: James Gibbs will be unavailable until August 5)
EVEN SMALL DIRT ROADS MAY THREATEN RAINFOREST BIRDS
Many birds don't cross the road in the Amazon; 7,500 km of new roads are planned
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The Royal flycatcher - a sensitive understory species in the Amazonian rainforest. |
It doesn't take much to keep birds from crossing roads deep in the Amazonian rainforest -new research shows that many species avoided crossing even a little-used dirt road. This is worrisome considering that Brazil is planning more than $40 billion of new infrastructure in the Amazon basin over the next decade, including 7,500 km of highways.
"Our results suggest that even narrow roads with low traffic volumes can reduce local movements of many insectivorous birds in Amazonia," say Susan Laurance, who did this work while at the University of New England in Armidale, New South Wales, and is now at the Smithsonian Tropical Research Institute in Balboa, Panama; Philip Stouffer of Louisiana State University, Baton Rouge; and William Laurance of the Smithsonian Tropical Research Institute in Balboa, Panama; in the August 2004 Conservation Biology.
While the Amazon basin has more than half of the world's remaining tropical rainforest, several million hectares are cleared each year. The Brazilian government has announced forest conservation measures but still plans extensive developments in the Amazon, including new roads, and gas and power lines. While such linear clearings have recently been found to increase illegal logging, mining and hunting, little is known about whether roads affect the way animals use the forest. Understory birds, which live on the ground and in the lower levels of the forest, are ideal for assessing the effects of roads because they are known to be sensitive to habitat disturbances.
Laurance and her colleagues compared the movements of understory birds across
a dirt road vs. through the tropical rainforest within 120 m of the road near
Manaus, Brazil. The road was 4-6 m wide and had little traffic (about 6-10 vehicle
passes per week). The forest clearing was 30-40 m wide when the road was bulldozed
in the late 1970s. However, the forest has regrown since then and the researchers
studied road sites with different levels of forest regeneration, including "cleared"
sites, which had little regrowth, and "tall regrowth" sites, which had a nearly
continuous canopy across the road.
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| Two types of rainforest road - cleared tall regrowth. |
Laurance and her colleagues found that the birds studied were far less likely to cross the road than to move through the forest: at each site, an average of only 12 species crossed the road while 27 moved through the forest. Solitary understory birds (such as the scale-backed antbird, cinnamon-crested spadebill and collared gnatwren) were the most severely affected by the road, rarely - if ever - crossing even where the forest had regenerated to form a nearly continuous canopy across the road.
"The narrow dirt road we studied had surprisingly large effects on some...understory insectivorous birds," say the researchers. "Our results are probably the best-case scenario because our study area is protected from hunters, loggers and heavy vehicle use."
The promising news is that many of the birds that avoided the cleared sites were more likely to cross the road at the site with the tallest regrowth. This suggests that the impact of roads could be minimized by preserving as much of the canopy as possible, which means limiting clearings to 20 m or less, say Laurance and her colleagues.
CONTACT:
Susan Laurance: 507-314-9206, 507-212-8252, laurances@tivoli.si.edu
Philip Stouffer: stouffer@lsu.edu
William Laurance: laurancew@tivoli.si.edu
INDIGENOUS PEOPLE CAN HELP ASSESS LOCAL BIODIVERSITY
Folk classification for Chinese plants is accurate, speedy
Time is running out for determining what species live where, which is key to protecting biodiversity. New research shows that conservationists may be able to assess biodiversity effectively and efficiently by tapping into the expertise of local people.
"Folk plant classification could be used in rapid assessment of plant species," say Lui Hongmao, Wang Jinhiu, Hu Huabin and Gao Lei of Xishuangbanna Tropical Botanical Garden in the August 2004 Conservation Biology.
Managers need biodiversity assessments to make conservation decisions, but there are not enough taxonomists to get the job done fast enough. The current rate of assessing biodiversity is so slow that it could take several thousand years to complete the inventory of species worldwide. However, most biodiversity is found in areas with indigenous people, who often have systems for classifying plants and animals.
To see if these folk classifications could be used for rapid biodiversity assessments, Hongmao and his colleagues compared the number of plant species identified by field botanists to those identified by the Dai people in Xishuangbanna, a region of southwestern China that has nearly a fifth (about 5,000) of the country's plant species even though it accounts for only 0.2% of the total land. The botanists and the local people independently surveyed the plants in three villages in areas ranging from sacred hill forests to community forests to home gardens.
The researchers found that the Dai people identified more than four-fifths of the plant species and that nearly 90% of the folk classifications corresponded with scientific classifications. The villagers also surveyed the plants twice as fast as the botanists, taking about 15 vs. 32 days, respectively. Besides speeding the process of assessing biodiversity, using folk classifications could encourage more local people to participate in and support conservation.
Hongmao and his colleagues also found that older villagers knew far more about native plants than younger people. When asked to identify 80 local plant species including lianas, herbs, shrubs and trees, 20-year-olds identified only about 60% accurately while 50-year-olds identified about 90% accurately. Folk classification systems are passed from generation to generation orally and through practical use, suggesting that asking local people to help inventory species could also help preserve their indigenous knowledge.
CONTACT:
Liu Hongmao: 86-691-8715463, liuhm@xtbg.ac.cn
Wang Jinhiu: heather197504@sina.com
Hu Huabin: huhb@xtbg.ac.cn
Gao Lei: gaolei@xtbg.org.cn
WILDFIRES IN THE WEST
Control fires near people, let more burn in the wilderness
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Wildlife in the western United States |
Wildfires in the western U.S. are bigger, hotter and scarier than ever due to fire suppression and other policies that have changed natural fire patterns. Today's fires can threaten wildlands and people alike, and a new analysis shows that reforming fire policies would help restore forests and rangelands while protecting people and homes.
"The cost of the existing approach to fire policy is escalating as wildfires increasingly become larger and more intense," says Jack Williams of Southern Oregon University in Ashland, Oregon, who presents this work with Dominick DellaSala of the World Wildlife Fund in Ashland, Oregon; Cindy Deacon Williams of Headwaters in Ashland, Oregon; and Jerry Franklin of the University of Washington, Seattle, in the August 2004 Conservation Biology. This work is part of a 13-paper special section called "Wildfire and Conservation in the Western United States" that was guest edited by Williams and DellaSala.
While fire is a natural part of the forests and grasslands in much of the western U.S., many of today's raging fires are not. Rather, they are the result of decades of fire suppression, logging, grazing and road building. In addition, climate change, invasive plants and suburban sprawl are making matters even worse. About 8.5 million acres burned in 2000, the peak fire year in recent history.
Federal policy aims to put out all forest fires by 10:00 am - but like it or not, western forests are going to burn. "Sound management must start from the realization that forests cannot be fire-proofed," says Franklin. The only questions are how often forests will burn and how extensive the fires will be.
The researchers recommend a flexible fire policy that varies with land use and weather.
In fire-prone areas where people live, the focus would be protecting them by, for example, suppressing fires and clearing vegetation within 100-200 feet of homes. In wildlands, the focus would be restoring ecological health by, for example, letting more fires burn as long as the weather is not too hot or windy.
Current fire policy also aims to make fires less intense by reducing forests' fuel loads, which typically means thinning them. However, there are two major problems with this. First, thinning usually leaves slash that can fuel fires and so actually make them spread even faster. Second, reducing fuels is only appropriate for some kinds of forests.
Reducing fuels is appropriate in forests that have unnaturally high fuel levels. For example, ponderosa pine and mixed conifer forests historically had more frequent, less intense fires that kept fuels from building up. But rather than just thinning these forests, the researchers recommend prescribed burning to reduce surface fuels as well as low-density thinning to reduce ladder and crown fuels, which spread fires through the tree tops.
In contrast, reducing fuels is not appropriate in forests where fuel levels are naturally high. For example, coastal Douglas fir, western hemlock and lodgepole pine forests historically had stand-replacing fires a century or more apart that allowed fuels to build up.
The researchers also recommend limiting post-fire treatments because they can damage forests. For example, grass seeding and mulching with hay can introduce exotic plants and impede natural forest regeneration; reforesting can create uniform stands that are more vulnerable to stand-replacing fires; and salvage logging typically targets the large trees that are critical to forest recovery.
"Our vision is to focus fire reduction treatments where they are needed most - in and around homes, and in the roaded and already logged fire-prone landscapes - while protecting wild areas like roadless lands and old-growth forests where ecological values are most important," says DellaSala.
CONTACT:
Dominick DellaSala: 541-621-7223, dellasal@wwfks.org
Jack Williams: williamj@sou.edu
Cindy Deacon Williams: williamj@sou.edu
Jerry Franklin: williamj@sou.edu
(NOTE: They will all be at the SCB meeting, which is August 30-July 2.)
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