Most Popular Posts
Categories
- Biodiversity (45)
- Climate change (137)
- Community-based conservation (45)
- Economics and conservation (113)
- Endangered species (185)
- Fresh water (41)
- Habitat (158)
- Invasive species (76)
- Marine (103)
- Monitoring (198)
- Restoration (133)
- Socio-political issues (148)
- Tools and technology (91)
Archives
- June 2010
- May 2010
- April 2010
- March 2010
- February 2010
- January 2010
- December 2009
- November 2009
- October 2009
- September 2009
- August 2009
- July 2009
- April 2009
- January 2009
- August 2008
- July 2008
- June 2008
- May 2008
- April 2008
- March 2008
- February 2008
- January 2008
- December 2007
- November 2007
- October 2007
- September 2007
- August 2007
- July 2007
- June 2007
- May 2007
- April 2007
- March 2007
- February 2007
- January 2007
Jul
22
2008
Susceptibility to bleaching is down to the fine-scale genetic type of a coral's dinoflagellate symbionts, according to a study published this week in PNAS. A group of University of Queensland marine biologists, led by Eugenia Sampayo, followed the fate of individually tagged corals Stylophora pistillata on the Great Barrier Reef, monitoring the conditions under which they suffered bleaching and subsequently recovered. The broad symbiont “clades” -- genetic subdivisions – weren't sufficient to explain the observed pattern of bleaching. However, within the “C” clade, some subtypes were more thermally tolerant than others. The discovery suggests a return to the drawing board might be needed to fully understand the role symbionts play in their reef-building host's ability to withstand changing climatic conditions. Source: Sampayo EM, Ridgway T, Bongaerts P & Hoegh-Guldberg O (2008) Bleaching susceptibility and mortality of corals is determined by fine-scale differences in symbiont type. Proceedings of the National Academy of Sciences USA DOI: 10.1073/pnas.0708049105
Image: © Giorgio Fochesato
Filed Under Climate change, Endangered species, Marine, Monitoring | Leave a Comment
Email This Post
Jul
14
2008
Tasmanian devils Sarcophilus harrisii are responding to a fatal disease by breeding earlier, according to scientists writing in PNAS this week. In the ten or so years since devil facial tumor disease – a poorly understood, infectious cancer – was first reported, it has spread throughout more than half the species' native range, leading to population declines of almost 90 percent. Cancerous cells are passed between individuals during aggressive interactions: unfortunately, the devil's mating behavior is somewhat on the rough side, with the result that populations exposed to the disease have markedly fewer surviving adults. That might be a problem, except for the dramatic increase in mating among juveniles, say Menna Jones – a researcher at the University of Tasmania – and colleagues. Females normally begin breeding at the age of two, going on to raise around three litters in all. In disease-stricken populations, however, the majority get just one early chance before reaching an untimely end, a chance most now take before their first birthday. Longer term hopes lie in the ability of selection to counter anything that's thrown at it. Good luck, Taz. Source: Jones ME, Cockburn A, Hamede R, Hawkins C, Hesterman H, Lachish S, Mann D, McCallum H & Pemberton D (2008) Life-history changes in disease-ravaged Tasmanian devil populations. Proceedings of the National Academy of Sciences USA DOI: 10.1073/pnas.0711236105
Image: © Jessica Jones
Filed Under Endangered species, Monitoring, Restoration | Leave a Comment
Email This Post
Jul
1
2008
Cows might cultivate an image of gentle, vegetarian all-round pleasantness, but don't be duped: their methane-laden flatus is the source of ten percent of the global annual emissions of this powerful greenhouse gas. Judith Capper and colleagues report a technological solution in this week's PNAS. The Cornell University researcher has studied the effects of supplementing cow feed with recombinant bovine somatotropin, the main effect of which is to boost milk production. The knock-on effect of this is a reduction of energy input and waste output for a given quantity of milk. The laced cows have a relatively low environmental impact, presenting conservation-minded sorts with a tricky dilemma: should we ditch high impact organic dairy farming for the pharmacologically modified alternative? Source: Capper JL, Castañeda-Gutiérrez, Cady RA & Bauman DE (2008) The environmental impact of recombinant bovine somatotropin (rbST) in dairy production. Proceedings of the National Academy of Sciences USA DOI: 10.1073/pnas.0802446105
Image: © VeSilvio
Filed Under Climate change, Economics and conservation, Socio-political issues, Tools and technology | 2 Comments
Email This Post
May
12
2008
A lethal disease is ripping through captive cheetah Acinonyx jubatus populations, hampering efforts to save the embattled felid from extinction. This week in PNAS, a research team led by Keiichi Higuchi at Shinshu University, Japan, claim that AA amyloidosis – a protein-folding disorder related to BSE (“mad cow” disease) – doesn't arise quite as spontaneously as previously thought. Although animals that succumb are usually already suffering another affliction, the presence of amyloid proteins in the feces of infected animals provides a potential transmission route among individuals that are housed together. Even a giant kitty-litter tray won't help, as the excreted infectious proteins can probably hang around in the soil too. Although the findings don't definitively establish a link between sick cheetahs and their poop, they strongly suggest it's a possibility to sniff out, so to speak. Source: Zhang B, Une Y, Fu X, Yan J, Ge F, Yao J, Sawashita J, Mori M, Tomozawa H, Kametani F& Higuchi K (2008) Fecal transmission of AA amyloidosis in the cheetah contributes to high incidence of disease. Proceedings of the National Academy of Sciences USA DOI: 10.1073/pnas.0800367105
Image © Eric Gevaert
Filed Under Endangered species, Monitoring, Restoration, Tools and technology | Leave a Comment
Email This Post
May
5
2008
It's often touted that the greatest climate change effects will be at higher latitudes – hence all those pictures of stranded polar bears that we're now worryingly familiar with. However, a study published today in PNAS argues that while the thermal shift at the tropics is likely to be relatively small, many species there are less tolerant to even the tiniest deviation from the more or less uniform temperatures they usually experience. Together with colleagues, Curtis Deutsch and Joshua Tewksbury – climate change scientists at UCLA and Washington universities respectively – assessed the impact of predicted climate change on land-based insects (a particularly speciose and temperature-sensitive group). In the steamy tropics, many bugs live life close to their thermal optimum, meaning increased average temperature could easily spell doom. At higher latitudes survival is a constant battle against the cold, so turning up the heat could be a good thing, at least for creepy crawlies. Unfortunately, the tropics are where it's at for insect biodiversity... Source: Deutsch CA, Tewksbury JJ, Huey RB, Sheldon KS, Ghalambor CK, Haak DC & Martin PR (2008) Impacts of climate warming on terrestrial ectotherms across latitude. Proceedings of the National Academy of Sciences USA DOI: 10.1073/pnas.0709472105
Image © Chanyut Sribua-rawd
Filed Under Climate change, Endangered species, Habitat | Leave a Comment
Email This Post
Apr
30
2008
Conservation projects often hinge on areas of land being given protection, but little is known about how well many protected areas actually do their job. Studying four of the world's major moist tropical forests, a group of Duke University researchers led by Stuart Pimm found that inaccessibility can be a tree's best friend. Protected areas within the Amazon and Congo forests, for example, nestle within largely well-forested surrounding areas, which keeps them relatively safe. The Atlantic Coast and West African protected areas, by contrast, are more fragmented: unfortunate, given their status as biodiversity hotspots. The study, published this week in PNAS, nonetheless throws welcome light on the way that large scale conservation initiatives work, or don't. Source: Joppa LN, Loarie SR & Pimm SL (2008) On the protection of “protected areas”. Proceedings of the National Academy of Sciences USA DOI: 10.1073/pnas.0802471105
Image © Joe Gough
Filed Under Community-based conservation, Economics and conservation, Endangered species, Habitat, Monitoring, Socio-political issues | Leave a Comment
Email This Post
Apr
7
2008
With hearts beating ten to the dozen and precious little by way of stored bodyfat reserves, you’d expect small mammals to be most susceptible to that grimmest of reapers, extinction. Yet the ability to sleep in times of stress could be the thing that saves them whilst their larger cousins are dropping like flies, according to a Scandinavian group of scientists led by University of Oslo researcher Nils Chr. Stenseth. Writing in PNAS this week, they present their findings from a large group of fossils from the Neogene Old World: large mammals have shorter “duration times” – they evolve more often, but also die out faster – than small mammals. Although our mega-mammalian taxonomic bias could perhaps explain this observation, there’s a more concrete possibility. The longest-lived groups of these fossils are littered with moles, mice, hamsters and flying squirrels, animals that typically exhibit “sleep-or-hide” – hibernating or burrowing – habits to weather out the worst of times. Us big guys just keel over. Source: Liow LH, Fortelius M, Bingham E, Lintulaakso K, Mannila H, Flynn L & Stenseth NC (2008) Higher origination and extinction rates in larger mammals. Proceedings of the National Academy of Sciences USA DOI: 10.1073/pnas.0709763105
Image © Rick Wylie
Filed Under Climate change, Endangered species, Habitat | Leave a Comment
Email This Post
Mar
4
2008
The line marking the transition between Vermont’s northern hardwood and boreal trees has moved around 100 metres uphill in just 40 years, according to a study published this week in PNAS. In 2004, researchers at Yale and Vermont universities, led by the latter’s Brian Beckage, revisited sites first mapped in 1964 that stretched between 550 and 1160 metres above sea level. As they went they noted changes in the species composition of the trees they found. Disease, acid rain (or snow) and an increase in freeze-thaw events have conspired to make life tougher for some species, easier for others. The observed elevational change was only around half that predicted through climate change models, however, suggesting that the northern hardwood trees will continue their ascent even if warming stops overnight, which of course it won’t. Disturbances, such as those caused by insect outbreaks, likely make this upward progression swifter: the question is whether the Green Mountains of Vermont are high enough for the boreal species to survive! Source: Beckage B, Osborne B, Gavin DG, Pucko C, Siccama T & Perkins T (2008) A rapid upward shift of a forest ecotone during 40 years of warming in the Green Mountains of Vermont. Proceedings of the National Academy of Sciences USA DOI: 10.1073/pnas.0708921105
Image © Jan Tyler
Filed Under Climate change, Habitat, Invasive species, Monitoring | Leave a Comment
Email This Post
Jan
28
2008
Canada has seven percent of the world’s forests, and they are looking like a liability. Far from being a carbon sink, say the Canadian Forest Service authors of a study published in PNAS, climate change will mean they produce a net surplus of carbon in more years than not. To make matters worse, according to Werner Kurz and colleagues, the scale of the emissions is completely unpredictable because they are driven by natural disturbances such as fire and disease outbreaks. Of these, two insect species play the lead roles: the mountain pine beetle Dendroctonus ponderosae and spruce budworm Choristoneura fumiferana. Taking it in turns to wreak havoc upon hundreds of thousands of square kilometres of forest, they force salvage logging operations that bring the trees’ locked-up carbon back into circulation sooner than anticipated. With fire intensities set to worsen in coming decades and the next major budworm outbreak imminent, some creative solutions to the problem of what to do about boreal forests are needed fast. Source: Kurz WA, Stinson G, Rampley GJ, Dymond CC & Neilson ET (2008) Risk of natural disturbances makes future contribution of Canada’s forests to the global carbon cycle highly uncertain. Proceedings of the National Academy of Sciences DOI: 10.1073/pnas.0708133105
Related story in Conservation magazine: That Sinking Feeling
Image © William Ciesla
Filed Under Climate change, Economics and conservation, Habitat, Invasive species, Monitoring, Socio-political issues | Leave a Comment
Email This Post
Jan
22
2008
There’s more than one kind of foreign debt. Climate change, ozone thinning, agriculture, aquaculture, deforestation and habitat conversion (how that euphemism grates!) all exert negative impacts at a global scale. The problem is that although we all pay the price only a small proportion of us get the benefit. And a group of scientists, led by Thara Srinivasan at the Pacific Ecoinformatics and Computational Ecology Laboratory, Berkeley, California, find that those causing the damage often pay disproportionately less than those who suffer its consequences most directly. Their compilation of World Bank data and Intergovernmental Panel on Climate Change scenarios, published in PNAS this week, reveals many startling gems. For example, the loss of storm protection through the degradation of 35 percent of the world’s mangrove since 1980 is equivalent in monetary value to the planet’s entire aquaculture industry. Yet 96 percent of shrimp are exported to high-income (mangrove-less) countries. On the positive side, Srinivasan and colleagues hope that the framework they have developed will allow the relative level of ecological debts between nations to be more accurately assessed, a crucial first step towards paying them off. Source: Srinivasan UT, Carey SP, Hallstein E, Higgins PAT, Kerr AC, Koteen LE, Smith AB, Watson R, Harte J & Norgaard RB (2008) The debt of nations and the distribution of ecological impacts from human activities. Proceedings of the National Academy of Sciences USA DOI: 10.1073/pnas.0709562104
Image © Laurin Rinder
Filed Under Climate change, Community-based conservation, Economics and conservation, Habitat, Socio-political issues | Leave a Comment
Email This Post