Drought stalls tree growth and shuts down Amazon carbon sink [View all]

[OKIsItJustMe]

http://www.exeter.ac.uk/news/featurednews/title_527669_en.html

[font face=Serif][font size=5]Drought stalls tree growth and shuts down Amazon carbon sink[/font]

[font size=4]A recent drought completely shut down the Amazon Basin’s carbon sink, by killing trees and slowing their growth, a ground-breaking study led by researchers at the Universities of Exeter and Leeds has found.[/font]

[font size=3]Previous research has suggested that the Amazon – the most extensive tropical forest on Earth and one of the “green lungs” of the planet – may be gradually losing its capacity to take carbon from the atmosphere. This new study, the most extensive land-based study of the effect of drought on Amazonian rainforests to date, paints a more complex picture, with forests responding dynamically to an increasingly variable climate.

…

By using long-term measurements from the RAINFOR network spanning nearly a hundred locations across the Amazon Basin, the team was able to examine the responses of trees. In both the first drought and the second the Amazon temporarily lost biomass. But while both droughts killed many trees, the 2010 drought also had the effect of slowing the growth rates of the survivors, suggesting that many trees were adversely affected but not to the point of death.

Lead author Dr Ted Feldpausch, senior lecturer in Geography at the University of Exeter, said: “The first large-scale, direct demonstration of tropical drought slowing tree growth is extremely important. It tells us that climate changes not only increase the rate of loss of carbon dioxide to the atmosphere, by killing trees, but also slow down the rate of uptake. And yet, the Amazon clearly has resilience, because in the years between the droughts the whole system returned to being a carbon sink, with growth outstripping mortality.”

…

Date: 6 July 2016[/font][/font]