Deforestation in Amazon is bad news for microbes

Posted by Flora Malein

Scientists have found that deforestation not only affects the diversity of plants and animals, but is bad news for the forest’s microbes too.

While it has long been known that deforestation in the Amazon leads to a net loss in the biodiversity of plants and animals, until now very little has been known about how it affects the smaller residents of the forest ecosystem: its many species of bacteria.
 
A team of scientists sampled a 100 square kilometer area, about 38 square miles, where rainforest has been converted to agricultural use in Rondônia, Brazil. They found that while microbial diversity increased over time in the converted pasture, compared to unlogged rainforest, there was a net loss in the numbers of species present. 
 
"We have known for a long time that conversion of rainforest land in the Amazon for agriculture results in a loss of biodiversity in plants and animals," says Jorge Rodrigues a biologist from the University of Texas, Arlington 
 
"Now we know that microbial communities which are so important to the ecosystem also suffer significant losses."
 
The finding is so concerning because while unseen to the human-eye, microbial communities are important for the healthy functioning of the rainforest ecosystem. Losing diversity affects the overall health of the rainforest, such as its ability to withstand changing climate conditions.
 
"The combination of loss of forest species and the homogenization of pasture communities together signal that this ecosystem is now a lot less capable to deal with additional outside stress," says Klaus Nüsslein, a microbiologist at the University of Massachusetts.
 
10 per cent of the world’s carbon is estimated to be stored in the Amazon rainforests. In Brazil the INPE or National Institute of Space Research has reported a loss of 17.1% of the Brazilian Amazon forest since the 1970s.
 
"Our findings are especially important because they support the idea that microbes are impacted by human-caused environmental change," adds Brendan Bohannan, a director at the University of Oregon's Center for Ecology and Evolutionary Biology.