The oil-rich and weedy plant jatropha has been hailed as the most promising source of biofuel on the planet, and one airline has already begun testing a jatropha-derived fuel in its jumbo jets. But a new analysis suggests that the plant may not be a miracle crop destined to solve all our energy problems: Current jatropha plantations are not realising the oil yields that drove the “Jatropha euphoria” [EcoWorldly].
It was previously thought that the hardy jatropha plant would require less water than other biofuel crops like sugarcane and corn and could grow in marginal soil, so growers wouldn’t have to take fertile land out of agricultural use. But the new study rebuts that assumption. “The claim that jatropha doesn’t compete for water and land with food crops is complete nonsense,” says study coauthor Arjen Hoekstra. The researcher says it’s true that the plant can grow with little water and can survive through periods of drought, but to flourish, it needs good growing conditions just like any other plant. “If there isn’t sufficient water, you get a low amount of oil production,” Hoekstra says [Technology Review].
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It’s not just humans who can take part in combating global warming–cows can play a role, too. Scientists say that the methane belched up by cows is a significant source of the greenhouse gas, and are searching for ways to reduce these burps. The digestive bacteria in the cows’ stomach produces the methane, which is the second-most significant gas (behind carbon dioxide) driving global warming. While methane is much less prevalent in the atmosphere than carbon dioxide, it traps heat 20 times more efficiently than carbon dioxide.
Researchers are examining a variety of tactics, including breeding or genetically engineering cows that belch less, or adjusting the bacterial mix in cows’ stomachs. But altering the cows’ feed has shown the most promise thus far. Since January, cows at 15 farms across Vermont have had their grain feed adjusted to include more plants like alfalfa and flaxseed — substances that, unlike corn or soy, mimic the spring grasses that the animals evolved long ago to eat. As of the last reading in mid-May, the methane output of [one test] herd had dropped 18 percent. Meanwhile, milk production has held its own [The New York Times].
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The concern over the declining honeybee population may be exaggerated, according to a controversial new study that shows their numbers are actually increasing globally. Alarm over a world pollination crisis is thus unfounded, say the researchers who analyzed Food and Agriculture Organization data and found that commercial domesticated bee hives have increased 45 percent in the past 50 years, to match growing demand for honey among a growing human population [AFP].
The study, published in Current Biology, says, “the declines in the U.S.A., some European countries and the former U.S.S.R. are more than offset by large increases elsewhere, including Canada, Argentina, Spain and especially China.” The study could help disprove a connection between regional declines, which have been attributed partly to parasitic mites and the general mystery known as colony collapse disorder, and a worldwide trend. But even if global bee populations continue to climb, researchers claim that there won’t be enough of them to go around. The real issue is not the honeybee numbers but the increasing work expected of them [CBC], the researchers argue.
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In another sign of Europe’s resistance to the genetically modified crops that have been widely accepted in the United States, Germany outlawed the cultivation of a genetically modified strain of corn produced by the U.S. company Monsanto. Germany joins five other countries — France, Austria, Greece, Hungary and Luxembourg — that have banned the pest-resistant maize despite its approval under a legally-binding EU directive [Nature News].
The strain of corn, known as Mon810, is the only transgenic crop approved in the European Union. Kari Matalone, a spokeswoman for Monsanto, said the corn — which is engineered to resist pests — had been approved for cultivation in Europe more than a decade ago and that no ill effects had been detected since then. “We don’t really understand where this decision is coming from,” Ms. Matalone said [The New York Times]. Monsanto also said it’s considering legal action against Germany.
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Researchers in Australia think they have found a solution to the country’s toxic cane toad problem: make Australian meat ants eat them. Cane toads—which can grow up to 8 inches (20 centimeters) in length—were imported from South America to Queensland [in northeast Australia] in 1935 in a failed attempt to control beetles on sugarcane plantations. Trouble was, the toads couldn’t jump high enough to eat the beetles, which live on top of cane stalks [AP]. Since their introduction… cane toads have spread through most of tropical Australia, eating and poisoning native animals [New Scientist]. No one has been able to get their population growth under control, and past suggestions to do so by introducing exotic diseases have only raised concerns about causing as much harm as the toads have themselves.
But a research team led by ecologist Rick Shine found that cane toads are more vulnerable to being eaten by Australia’s predatory meat ants than are native frogs, which may allow the ants to be used as a “safe” biocontrol agent that would not interfere with native frog species. Shine said the team plans to try ways of encouraging meat ants to build colonies near toad breeding ponds. One way would be to plant trees the ants favour [The Australian]. He is hopeful the strategy will work because unlike native frogs, cane toads are active during the day, when meat ants roam about scavenging for food. Toads also tend to breed in ponds that are out in the open sun, which results in their young emerging onto bare, baked mud areas, a habitat where meat ants like to forage [Sydney Morning Herald]. The toad is also more vulnerable because it lays its eggs in the dry season when water is low and there’s little protective vegetation at the pond’s edge [The Australian].
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In preparation for future oil shale mining projects near the Rocky Mountains, six oil companies have gained rights to billions of gallons of water in the American West, potentially jeopardizing water supplies throughout the region, according to a new report by Western Resource Advocates [pdf], an environmental group. It is still preliminary to speculate on the implications of the findings, but many are concerned that if the companies put their rights to use, water will be shifted away from agriculture and community use.
Using public records, the report examines more than 200 water rights held by six energy companies, including Shell and ExxonMobil, which, it is estimated, are collectively entitled to divert at least 6.5 billion gallons of water from rivers in western Colorado, as well as almost 2 million acre-feet of water from the state’s reservoirs, which is enough to supply the Denver metro area for six years. Shale oil production is a water-intensive process: up to five barrels of water are consumed for every barrel of oil produced. This means that projects producing 1.55 million barrels of oil per day would require 378,000 acre-feet of water each year, compared to the Denver metro area’s consumption, which is less than 300,000 acre feet. Should oil shale production hit full stride in the next 15 to 20 years — something the White House under President George W. Bush tried to accelerate by opening up 2 million acres controlled by the Bureau of Land Management to leasing and approving royalty rates and leasing rules — there will be a major political battle over water rights [Colorado Independent].
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In Liberia, a caterpillar infestation has turned into a national emergency. They began advancing out of the forests several weeks ago. From off in the bush, townspeople at the epicenter of the plague heard a low roar, like the sound of heavy rain cascading down through the leaves. It was caterpillar droppings. In early January, when the long, black caterpillars reached the creeks that serve as the main water sources for the town of Belefanai in north-central Liberia, the creatures’ feces instantly turned streams dark and undrinkable [National Geographic News]. Since then, things have only gotten worse. The caterpillars are eating their way through coffee and cocoa fields, and thousands of people have fled their homes.
The caterpillars are native to West Africa but have never been reported as a widespread pest in Liberia. Researchers say the cause of this population explosion is still mysterious; Liberian agriculture official Winfred Hammond says his best bet is that the boom was related to last year’s strange climate. The caterpillars live in the forest, and their population is usually kept down by wasps that lay eggs on the moth’s cocoon and eat the caterpillars, Mr. Hammond said. But the rains last year were unusual. Downpours as late as Christmas may have interrupted the reproduction cycle of the wasps that prey on the caterpillars [The New York Times].
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Locusts are prompted to band together in enormous, destructive swarms by the same brain chemical that is linked to happiness in humans. A fascinating new study has found that locusts that are about to swarm experience a sudden surge of serotonin, the same neurotransmitter that’s targeted by antidepressant drugs. “Here we have a solitary and lonely creature, the desert locust. But just give them a little serotonin, and they go and join a gang,” observed Malcolm Burrows [AP], one of the study’s authors.
Researchers say the findings may lead to methods to block the formation of locust swarms. These infestations, which can cover hundreds of square miles and involve billions of vegetation-munching insects, can devastate agriculture and cost tens of millions of dollars to control [The New York Times].
Because locusts usually avoid each other, it’s only dire circumstances that bring them together in buzzing hordes. For instance, unpredictable desert rains cause vegetation blooms, which in turn makes locust populations skyrocket. But as the rains abate and fertile land shrivels up, locusts crowd together in the remaining green patches. Eventually, the swarm trigger goes off and the locusts take to the skies—”a strategy of desperation driven by hunger,” [National Geographic News], says coauthor Stephen Rogers. When they make that behavior shift they also change appearance dramatically, going from light green to dark brown.
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Contrary to conventional wisdom, fish in the Nile delta are thriving in waters polluted with fertilizers and sewage, according to a new study. While nitrogen-rich runoff usually causes excessive growths of algae and plankton that suffocate other marine life, the Nile delta is different because it has suffered from a lack of autotrophs (that fish feed on) ever since the Aswan Dam was built in the 1960s. Researchers found that more than 60 percent of the current fishery production in the region can be attributed to human-generated runoff. “This is really a story about how people unintentionally impact ecosystems,” explained co-author Autumn Oczkowski [BBC News].
The building of the Aswan Dam on the Nile blocked off much of the fertile floodwater that drains into the Mediterranean Sea, which in turn produced a sharp fall in the number of fish being landed by Egypt’s fishermen. “But in the late 1980s, the coastal fishery began to exhibit a surprising recovery,” the researchers observed. “Today, landings are more than three times the pre-dam level” [BBC News]. The increase in fish production coincided with the rise in fertilizer use along the Mediterranean coast. To quantify the effect, researchers collected more than 600 fish from four regions contaminated by runoff and two regions that were not. In regions affected by runoff, the fish contained nitrogen isotopes that could be traced to anthropogenic sources of nitrogen, according to the study published in the Proceedings of the National Academy of Sciences.
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Domesticated pigs got their stripes and spots and other distinctive markings thanks to deliberate breeding efforts by the earliest farmers over the course of thousands of years, according to a new study of pig genetics. While there’s no clear evidence of what motivated those early farmers to change their pigs’ coats, study coauthor Greger Larson says a number of possible reasons present themselves. “One is that it facilitated animal husbandry since it is easier to keep track of livestock that are not camouflaged. Another could be that it has acted as a metaphor for the improved characteristics of the early forms of livestock compared with their wild ancestors.” But another possibility, Larson said, “is that the early farmers were as amused and as taken with biological novelty and diversity as we are today” [HealthDay News].
Novelty may have been the desired characteristic in the first agricultural settlements, but in the wild opposite forces were at work to produce pigs with a consistent brown-black color that served as camouflage. “Every time a gene mutation arose in the wild causing coat colour to change, it was eliminated immediately,” says Greger Larson…. “So if a black piglet showed up, that was the one picked off by a predator” [New Scientist].
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The ravages of global warming could be mitigated by convincing farmers around the world to plant slightly different varieties of corn, barley, and millet, according to a new study which examines the reflective properties of crop plants.Plants reflects short wave energy back out to space much like snow and other light surfaces do. This is known as the albedo effect and is a key component of calculating the effects of climate change. As Arctic ice melts and is replaced by dark water, for instance, the region’s warming is expected to accelerate. Plants have higher or lower reflectivity depending on things like the shape and size of their leaves and how waxy they are [New Scientist].
Lead researcher Andy Ridgwell and his colleagues were inspired in their work by the growing talk of geoengineering fixes for global warming, including ambitious and large-scale projects like seeding the Southern Ocean with iron to encourage algae blooms or building a huge sunshade in the Earth’s orbit. The researchers say their proposal, which they call bio-geoengineering, is more realistic because it uses existing infrastructure. “Arable agriculture is already a global-scale undertaking,” Dr. Ridgwell said. “We wondered whether you might grow slightly different crops and have some sort of climate impact.” … [I]t wouldn’t cost much, and it wouldn’t require much international cooperation. “It’s very practical, and it could just be done,” he said. “It’s not some trillion-dollar pie-in-the-sky idea” [The New York Times].
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Two-headed fish are turning up in Australia’s Noosa River, and experts believe it’s due to something in the water. Millions of fish larvae have been found with two heads (that means one more eye than Blinky) and none of them survive to adulthood. Aquatic animal specialist Matt Lando puts the blame on noxious chemicals wafted from a nearby macadamia nut farm. He said, “When we used the water on-site or have taken bass from the Noosa River those fish appear to have been contaminated and they give rise to deformed or convulsing larvae… I have been working in aquaculture for 10 years and this is the first time I have ever seen anything like it” [AFP].
Last October, Lando sent a report to the Department of Primary Industries and Fisheries in which he identified the pesticide endosulfan and the fungicide carbendazim, both used on the neighboring macadamia nut plantation, as the likely culprits. “The timing between the mist spraying and the affected larvae fits hand in glove,” he said. Dr Landos’s report also found that chickens, sheep and horses raised at the Sunland Fish Hatchery at Boreen Point were recording abnormally high levels of foetal deaths and birth defects [The Sydney Morning Herald]. Both chemicals are currently legal in Australia. Carbendazim was voluntarily withdrawn from the U.S. market in 2001 by the chemical company Dupont. Endosulfan is already banned in 55 countries and New Zealand will become the 56th starting this Friday.
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Three years ago, a controversial study alarmed climate researchers by stating that plants produce methane, a potent greenhouse gas, as part of their normal operations. Those findings went against the standard idea that forests are one of our few buffers against global warming since they absorb and store carbon dioxide; suddenly, scientists began wondering if planting more trees might do more harm than good. But now a new group of researchers says it has refuted the 2006 study, although the scientist who did the original work is not backing down from his claims.
In the new study, to be published in the Proceedings of the Royal Society B, researcher Ellen Nisbet first looked at how that earlier study was conducted, and saw that the earlier researchers had put glass chambers over plants growing in the wild and measured how the mix of gases within the chamber changed. Nisbet says that procedure meant that the plants could have absorbed methane from the soil, instead of creating it themselves. Part of her team’s work involved growing several different varieties of plant, including maize and rice, in media that contained no organic material, so eliminating the chances of methane being formed through decay in soil. They found during these experiments, conducted in closed chambers, that the plants produced no methane at all [BBC News].
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The human penchant for animals of impressive size has left some of the most hunted species smaller and weaker. A new study finds that human-induced selection, through activities like hunting and fishing, is having a profound effect on the evolution of many species. “Human-harvested organisms are the fastest-changing organisms yet observed in the wild” [National Geographic News], said lead researcher Chris Darimont. The pattern of loss to human predation like hunting or harvesting is opposite to what occurs in nature or even in agriculture [The New York Times]; instead of survival of the fittest, human predation encourages survival of the scrawniest.
In nature, predators typically take “the newly born or the nearly dead,” Dr. Darimont said [The New York Times], because healthy individuals are more difficult and dangerous to catch. But human hunters and gatherers target the biggest and strongest individuals. To find out how human predation affects species evolution, researchers examined previously documented, hunting-induced changes across 29 species in 40 locations, including commercially targeted fish, bighorn sheep, caribou, and several marine animals such as limpets and snails. Two plant species were also included in the analysis: Himalayan snow lotus and American ginseng [National Geographic News]. The hunted species were compared with 25 species that are not hunted but subject to other human interference and another 20 species that face only “natural” pressures, such as climate, competition for resources, or animal predators [National Geographic News].
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By 2100, climate change could mire half the world’s population in a food crisis, according to a new report. The analysis is based on data from 23 climate change models gathered in the 2007 report by the Intergovernmental Panel on Climate Change. It predicts a 6 degree Fahrenheit rise in average growing-season temperatures in many areas and a 20 to 40 percent drop in crop yields. The hardest hit will be the tropics and subtropics, home to some of the world’s poorest populations. “You are talking about hundreds of millions of additional people looking for food because they won’t be able to find it where they find it now” [Reuters], said study co-author David Battisti.
According to the report in Science [subscription required], if the buildup of greenhouse-gas emissions isn’t halted or slowed, the odds are higher than 90 percent that average growing-season temperatures will be higher than in recorded history across a big swath of the planet by the end of the century [The Seattle Times]. Rising temperatures may initially speed crop growth, but will ultimately reduce plant fertility and grain production. Beyond the rising temperatures, the danger to agriculture will be aggravated by drought.
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