What Happens When a Rainforest Burns?

The wettest rainforest in the continental United States had gone up in flames and the smoke was so thick, so blanketing, that you could see it miles away.  Deep in Washington’s Olympic National Park, the aptly named Paradise Fire, undaunted by the dampness of it all, was eating the forest alive and destroying an ecological Eden.  In this season of drought across the West, there have been far bigger blazes but none quite so symbolic or offering quite such grim news.  It isn’t the size of the fire (though it is the largest in the park’s history), nor its intensity.  It’s something else entirely — the fact that it shouldn’t have been burning at all.  When fire can eat a rainforest in a relatively cool climate, you know the Earth is beginning to burn.
...
The very rarity of such fires speaks to the anthropogenic nature of the origins of this one.  After all, a temperate rainforest as a vast collection of biomass and so a carbon sink is only possible thanks to the rarity of fire in such a habitat.  According to the World Wildlife Fund, “With a unique combination of moderate temperatures and very high rainfall, the climate makes fires extremely rare” in such forests.

The natural fire cycle in these forests is about 500 to 800 years.  In other words, once every half-millennium or more this forest may experience a moderate-sized fire.  But that’s now changing.  Mark Huff, who has been studying wildfires in the park since the late 1970s, told Seattle’s public radio station KUOW that in the past half-century there have already been “three modest-sized fires” here, including the Paradise, though the other two were less destructive.  According to a National Park Service map (“Olympic National Park: Fire History 1896-2006”) in the western rainforest, during that century-plus, two lightning-caused fires burned more than 100 acres and another more than 500 acres.

If, however, fires in the rainforest become the new normal, comments Olympic National Park wildlife biologist Patti Happe, “then we may not have these forests.”

A team of international climate change and rainforest experts published a study earlier this year warning that, “without drastic and immediate cuts to greenhouse gas emissions and new forest protections, the world’s most expansive stretch of temperate rainforests from Alaska to the coast redwoods will experience irreparable losses.”  In fact, says the study’s lead author, Dominick DellaSala, “In the Pacific Northwest … the climate may no longer support rainforest communities.”

Read more at What Happens When a Rainforest Burns?