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Mediterranean summers in The Netherlands?
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IN BRIEF Europe, get ready to feel the heat
Pines growing lonesome and redwoods rarer in US West THE majestic old trees of the western US are disappearing twice as fast as they were three decades ago, and climate change is probably to blame. Philip van Mantgem of the US Geological Survey and colleagues collected data from old forests on the West Coast as well as in Arizona, Colorado and Idaho. In 87 per cent of the study sites, trees are dying faster than replacements can spring up. The Pacific Northwest was worst affected, with death rates doubling every 17 years (Science, DOI: 10.1126/science.1165000) . “We may only be talking about annual tree mortality
changing from 1 per cent to 2 per cent, but the implications are huge,” says Mark Harmon, an ecologist at Oregon State University in Corvallis. The team believes the rise in temperatures across the region is the main culprit. It could be drying the trees out, or encouraging parasites such as beetles and fungi. If warming kills trees it could create a vicious circle, releasing even more carbon dioxide into the atmosphere. They considered the theory that suppressing forest fires ultimately increases tree mortality rates, but trees are dying faster even on plots that have not burned – and thus not had fires suppressed – for 200 years. Mark Ashton at Yale University says the findings are interesting but hard to extend to the US East Coast or Europe, where old, unmanaged forests are rarer.
Mini marine animals challenge evolution AN UPDATED family tree of the animal kingdom could radically change the way we think about the evolution of species. According to conventional thinking, simple animals, including sponges, jellyfish and corals, evolved step-by-step in a linear fashion into those with more complex bodies, such as mammals. Now Rob DeSalle of the 14 | NewScientist | 31 January 2009
American Museum of Natural History in New York and his colleagues have challenged this way of thinking. The team analysed DNA and other molecular evidence across the animal kingdom, including tiny sea creatures called placozoans. They have found that the placozoans are the closest living thing to the ancestor of all animals.
More intriguingly, these simple creatures belong to a group of organisms that, as DeSalle’s team discovered, evolved in parallel to those that later developed into humans. Since this deep division was forged half a billion years ago, before animals developed nerves, the finding implies that the nervous system developed twice – evolving independently in simple organisms like jellyfish and also in complex animals.
A CENTURY from now, Spain and Italy will be enduring baking, parched summers while residents of central and north-west Europe will be experiencing what we now think of as Mediterranean warmth. Reindert Haarsma and his team from the Royal Netherlands Meteorological Institute in De Bilt used existing computer models to study changes in weather patterns resulting from the expected global warming. These indicated that summer temperatures in southern Europe would rise by 2 to 3 °C compared with today’s, and that lack of rain would dry up the soils. The hot, dry air above these arid soils would then rise and expand, creating a lowpressure zone over the region. Winds circulating anticlockwise around this zone would feed continental air to more northerly areas, raising temperatures there too (Geophysical Research Letters, DOI: 10.1029/2008GL036617).
Wood stoves cause Asian brown haze THE brown haze that hangs over southern Asia during the winter is largely the result of burning biomass for cooking and heating. Örjan Gustafsson of Stockholm University in Sweden and his team studied the proportion of carbon14 in soot particles collected from the top of a mountain at Sinhagad, India, and from the Maldives in the Indian Ocean. As its half-life is about 5700 years, most of the carbon-14 in fossil fuels would have decayed long ago. So the high levels of carbon-14 found in the soot show that wood stoves must be the source of two-thirds of the haze (Science, DOI: 10.1126/ science.1164857). Helping villagers switch to solarpowered stoves would reduce the brown haze, says Gustafsson.
IN BRIEF Europe, get ready to feel the heat
Pines growing lonesome and redwoods rarer in US West THE majestic old trees of the western US are disappearing twice as fast as they were three decades ago, and climate change is probably to blame. Philip van Mantgem of the US Geological Survey and colleagues collected data from old forests on the West Coast as well as in Arizona, Colorado and Idaho. In 87 per cent of the study sites, trees are dying faster than replacements can spring up. The Pacific Northwest was worst affected, with death rates doubling every 17 years (Science, DOI: 10.1126/science.1165000) . “We may only be talking about annual tree mortality
changing from 1 per cent to 2 per cent, but the implications are huge,” says Mark Harmon, an ecologist at Oregon State University in Corvallis. The team believes the rise in temperatures across the region is the main culprit. It could be drying the trees out, or encouraging parasites such as beetles and fungi. If warming kills trees it could create a vicious circle, releasing even more carbon dioxide into the atmosphere. They considered the theory that suppressing forest fires ultimately increases tree mortality rates, but trees are dying faster even on plots that have not burned – and thus not had fires suppressed – for 200 years. Mark Ashton at Yale University says the findings are interesting but hard to extend to the US East Coast or Europe, where old, unmanaged forests are rarer.
Mini marine animals challenge evolution AN UPDATED family tree of the animal kingdom could radically change the way we think about the evolution of species. According to conventional thinking, simple animals, including sponges, jellyfish and corals, evolved step-by-step in a linear fashion into those with more complex bodies, such as mammals. Now Rob DeSalle of the 14 | NewScientist | 31 January 2009
American Museum of Natural History in New York and his colleagues have challenged this way of thinking. The team analysed DNA and other molecular evidence across the animal kingdom, including tiny sea creatures called placozoans. They have found that the placozoans are the closest living thing to the ancestor of all animals.
More intriguingly, these simple creatures belong to a group of organisms that, as DeSalle’s team discovered, evolved in parallel to those that later developed into humans. Since this deep division was forged half a billion years ago, before animals developed nerves, the finding implies that the nervous system developed twice – evolving independently in simple organisms like jellyfish and also in complex animals.
A CENTURY from now, Spain and Italy will be enduring baking, parched summers while residents of central and north-west Europe will be experiencing what we now think of as Mediterranean warmth. Reindert Haarsma and his team from the Royal Netherlands Meteorological Institute in De Bilt used existing computer models to study changes in weather patterns resulting from the expected global warming. These indicated that summer temperatures in southern Europe would rise by 2 to 3 °C compared with today’s, and that lack of rain would dry up the soils. The hot, dry air above these arid soils would then rise and expand, creating a lowpressure zone over the region. Winds circulating anticlockwise around this zone would feed continental air to more northerly areas, raising temperatures there too (Geophysical Research Letters, DOI: 10.1029/2008GL036617).
Wood stoves cause Asian brown haze THE brown haze that hangs over southern Asia during the winter is largely the result of burning biomass for cooking and heating. Örjan Gustafsson of Stockholm University in Sweden and his team studied the proportion of carbon14 in soot particles collected from the top of a mountain at Sinhagad, India, and from the Maldives in the Indian Ocean. As its half-life is about 5700 years, most of the carbon-14 in fossil fuels would have decayed long ago. So the high levels of carbon-14 found in the soot show that wood stoves must be the source of two-thirds of the haze (Science, DOI: 10.1126/ science.1164857). Helping villagers switch to solarpowered stoves would reduce the brown haze, says Gustafsson.