Posted on behalf of Ana Belluscio.
Nine months after the eruption of the Puyehue volcano in Chile forced thousands to flee for their lives, its impact is still being felt in the surrounding region.
Puyehue, located in the southern Chilean Andes, began erupting on 3 June 2011, throwing millions of tonnes of ash into the sky for more than two weeks.
According to a report released on 15 February by the Faculty of Agronomy of the University of Buenos Aires (FAUBA) and the National Scientific and Technical Research Council (CONICET), the ash has had a considerable effect on plant growth in the surrounding areas of Chilean and Argentine Patagonia, with some regions seeing crop yields reduced by more than 50%.
“We are looking at the lowest production values of the last 12 years”, says FAUBA researcher Gonzalo Irisarri. This has also affected livestock grazing, one of the main sources of economic income in the region.
After the eruption, the ash layer — up to 45 centimetres in some regions — covered soil and plants, reducing their photosynthetic capacity. This was exacerbated by the drought the country experienced in December and January.
According to CONICET researcher Javier Grosfeld, the data show that plants’ growth was effectively delayed by at least a month. Pastures were the most affected, and regeneration will be particularly slow in areas were the ash layer exceeded 15 cm, he says.
Stones and dust released by the volcano have also damaged some of the lakes of Argentine Patagonia (see above). “Almost nine months after the eruption there are still huge floating rafts of pumice” that prevent sunlight reaching the lake, says Esteban Balseiro of the CONICET-University of Comahue in Bariloche, Argentina. This results in fewer plankton, which may have knock-on effects for creatures that depend on them as a food source.
Balseiro, however, is confident that the ecosystems will recover in due course.
Image: Esteban Balseiro