ESA 2009: The ecological lessons of the Cerro Grande fire
On Friday, before the meeting properly started, I went along on a field trip to Los Alamos, New Mexico. If the name rings a bell, it is probably because the town was once a secret government enclave, r&d hub of the Manhattan project, and so the intellectual home of the atomic bomb.
There is still an active government lab there today, home of, among other things, this week’s world’s fastest computer.
But Los Alamos is also famous in New Mexico for being partially destroyed by the 2000 Cerro Grande fire. The blaze was massive--190 km²--and it torched 400 houses and bits of the lab. It was also started on purpose, as a “controlled burn”.
Before 1880, the arid forests of New Mexico burnt regularly, in fires started by lightning and local peoples. These were thought to be mostly low-intensity fires which stayed on the ground, burning out smaller plants but leaving trees unscathed (see image of such a low-intensity fire).
The controlled burn was part of an effort to mimic this regime, but a history of fire suppression left many areas thick with potential fuel, and a severe drought left that fuel as dry as bone. So a fire started to clear out low fuel and help reduce the threat of big fires turned out to start a big fire itself.
As we drove through the area that burnt nine years ago, we saw many dead ponderosa pines, black and white, covering the hillsides in the Jemez mountains. Underneath grew grasses that had been seeded via small planes to help fight erosion. The fire sterilized a good thick layer of soil, which then promptly washed downhill in the next big rain, choking water drainages. Our tour guide, Randy Balice, Fire Hazard Assessment Specialist for Los Alamos looked over the scene gloomily.
But Belice had good news to share as well. This year, a lightning-started fire “burnt just like fires should burn, if you like those pre-1880 type fires.” While parks department and other officials kept a careful eye on it, it rippled through the undergrowth, clearing out dry fuel, and then got rained out.
“That fire was a renewal,” said Belice.
