These trees deserve a hug
THE FUEL-EFFICIENT FOREST
THE NEWS Money may grow on trees after all. Farmers in North Queensland, Australia, are planting at least 20,000 “diesel trees” (Copaifera langsdorfii), native to Brazil. These can be tapped – like maple or rubber trees – to harvest up to 40 litres a year of a natural diesel, needing only simple filtration before it’s ready to use in a tractor or truck.
THE BUZZ Biofuels made from food crops such as corn, soy and palm oil are increasingly getting a bad name for depleting our food stores and requiring large amounts of energy and land to be produced. So biofuels made from other sources, such as grasses, trees and algae, look appealing. Is Copaifera a perfect solution? Not really: The trees will take at least 15 years to mature; they can’t be grown outside the tropics; and they require large volumes of water (scarce in the rest of Australia).
THE BOTTOM LINE “Diesel trees” could never satisfy our global energy needs. But in North Queensland, farmers hope that one hectare will produce 12,000 litres of diesel a year – theoretically enough to make a small farm self-sufficient.
PESTICIDES AND PARKINSON’S
THE NEWS Scientists have found a link between Parkinson’s disease and pesticides: A study in the journal BMC Neurology reports that people with the disease were more likely to have been exposed to insecticides than their healthy relatives.The issue is controversial: There are many studies that prove the link, alongside many other studies that show no connection. Now with several recent studies finding an association, “there seems to be a consistent implication of pesticide exposure as one risk factor,” says William Scott of the University of Miami, one of the authors of the study. He says the chemicals may trigger the development of the disease in biologically vulnerable people who have a predisposition for Parkinson’s.
THE BUZZ The cause of Parkinson’s disease is a mystery, with known genes accounting for only a tiny fraction of cases. Pesticides – already implicated in thousands of scientific studies as responsible for many cancers, birth defects and brain disorders – are increasingly being fingered as a risk factor for Parkinson’s. “It seems obvious to us that a way to protect people would be to ban pesticides from use on gardens and lawns,” says Gideon Forman, executive director of the Canadian Association of Physicians for the Environment, which has long campaigned on the issue.
THE BOTTOM LINE Others agree that the use of pesticides is not worth the risk. More than 1,000 Canadian municipalities, including Toronto, Vancouver and the entire province of Quebec, have banned the “cosmetic” use of pesticides on residential lawns and gardens. Ontario Premier Dalton McGuinty is expected to propose a province-wide ban this month.
JUNGLE REJUVENATION
THE NEWS It may be possible to regrow a rain forest. Fifteen years ago in Costa Rica, Cornell University’s Professor Carl Leopold planted a mix of native tree species on abandoned pasture that had been trampled on by cattle for half a century, resulting in soil that was compacted and nutrient-poor. Now, he reports in the current issue of the journal Ecological Restoration, trees he planted are flourishing, despite the initially poor soil. And – even better – hundreds of other native plants have established themselves in the area.
THE BUZZ Traditional thinking has been skeptical about bringing a rain forest back to life. The ecosystem is so complex, with so many thousands of different species, that regeneration is far more complicated than just planting millions of saplings of one kind of tree (as we do in Canada every summer). Ecologists have estimated that it could take up to 800 years for a rain forest to grow back – if at all.
THE BOTTOM LINE But if you plant a mix of species, you may be able to kick-start the process. “I think you could get pretty close to a functioning, natural rain forest in 100 or 200 years,” Dr. Leopold says, especially if there are pristine forests nearby from which other species could migrate.
ACID REFLUX
THE NEWS The air in England has certainly improved since the Industrial Revolution, but pollutants in the soil are still having an effect. Bacteria that eat iron and sulphur in the mountainous Peak District are excreting acid, degrading the soil and worsening erosion, Patricia Linton from Manchester Metropolitan University told the annual meeting of the Society for General Microbiology in Edinburgh last week. These bacteria are normally found only in iron-rich old industrial sites, so she was surprised to find them on the remote peat lands.
THE BUZZ Dr. Linton also found high levels of lead and zinc in the soil, two more relics of the Industrial Revolution. And the more acidic the soil, the more “mobile” the lead and zinc become – the heavy metals move around more easily and can be absorbed by living things. Dr. Linton and her team are now investigating whether the acid in the soil is related to heavy metals in waterways, reservoirs, vegetation and wildlife. More acidic soils might also release more carbon to the atmosphere, “which could actually make climate change worse,” Dr. Linton says.
THE BOTTOM LINE Pollution can have unexpected effects long after we put out the fires. Clean-air legislation in Britain cut heavy-metal pollution from mines and smelters more than 50 years ago, but it may be a while before the damage stops.