March 10, 2009
A thirty-year research project has shown that the Amazon rainforest is unexpectedly susceptible to drought.
There is now sound proof that trees dying in a drought result in substantial losses of carbon.
The verdant foliage usually sucks in almost two billion tonnes of CO2 each year, a major factor in global warming.
The project discovered that over around 25 years the Amazon forest was a huge carbon reservoir.
The same effect has been noted in Africa.
For many years the tropical forests have captured 20 percent of the world’s carbon emissions fossil fuels.
Professor Oliver Phillips, of Leeds University and head of the study said that the Amazon basin has long reduced the speed of global warming but it would be perilous to depend on it.
His work shows that the world’s carbon reduction could slow down or even go back up, and in this case greater reductions in greenhouse gas emissions will be necessary.
The data from over 40 organisations worldwide, was collected by 68 scientists from 13 countries in the very bad drought of 2005, which affected the flora in the rainforest very detrimentally.
The teams, who studied over more than 100 parts of the forest over its 600 million hectares, identified and measured more than 100,000 trees, and documented new trees and dead ones.
Weather models were determined and recorded.
The scientists were working with RAINFOR, the sole research organisation dedicated to examining the rainforests of the Amazon.
To the eye, the largest part of the Amazon exhibited minor drought damage but the figures show that trees died more quickly, Professor Phillips said.
The study says that the drought created a further five billion tonnes of carbon dioxide, which is higher than the joint European and Japanese emissions each year.
Abel Monteagudo, a botanist from Peru and report co-author, said some trees, including some valuable palms were particularly at risk, proving that drought also endangers species diversity.
The Amazon contains over half of the planet’s rainforest, a region 25 times bigger than the UK.
Nowhere in the world are there so many species, nor the same influences on carbon capture.
The exact vulnerability of the Amazon basin is now understood and thanks to the study we now know the precise sensitivity of the Amazon to warming and drought.
If the drought recurs, global warming will accelerate and cause future, harmful droughts.