Tuesday, September 10, 2019

There Are No Natural Fires In Tropical Rainforests

Since the Amazon fires are focusing our attention more on the destruction of the rainforests, let me note that there’s no such thing as “natural” tropical rainforest wild fires. Any rare natural fires that do occur only burn forest floor leaf litter with flames no more than a few inches in height. People who live in tropical rainforests know this and take it for granted that we do too. 

Paleoecology, the study of ancient environments, offers unique insights into how the first Amazonian peoples manipulated fire in the landscape, the effects of those fires on the forest’s ecology over time, and lessons for today. Layers of charcoal buried below the rainforest’s surface reveal that for ‘thousands of years’, the Amazon’s ancient inhabitants used fire to clear the ‘forest floor’ for agriculture—and that it had a lasting effect, making ‘those areas’ more fire prone today. But unlike many of the current fires, set to flatten the forest entirely, those indigenous fire practices left trees standing.

no natural fire tropical forests

Note: When you see televised footage of Amazonian grass and brush burning in the news, you’re seeing what was once tropical forest that has been forcibly cleared previously at some point in time. 
         I personally remember when only 1% of the rainforest had been cleared. We’re now at about 20% gone and during that time Brazilian weather stations have recorded decreasing rainfall. With a further 5 - 15% of deforestation, the positive precipitation water cycle feed back loop that keeps 50-80% of the ecosystem’s moisture in play will be broken. Once that happens, the Amazon will get drier and drier (and that’s not even factoring in any climate change variables). Not only will the plants and animals disappear, but the agriculture that crowded them out will also wither.