Nice pics - sad about the loss of vegetation but as you say it's often naturally occuring (lightning). Down here in Australia we have very bad bushfires most summers - worse now considering we've been in a drought for a decade.
There is a round of the UCI MTB World Cup in Canberra, Australia this year (Aug 30-31) that's being held at a MTB park built on a mountain completely wiped out by bushfires in 2003:
http://en.wikipedia.org/wiki/Canberra_bushfires
The fires were so hot and the wind so strong that the pines looked like those in the photos above, only bent over in the direction the wind was blowing - that's how they stayed (they made a memorial of this seen in the link above). Over 500 homes lost, the Observatory at the top of the mountain destroyed, and the soil is so badly damaged it will take years to repair, if ever - it's like talcum powder. But there's plenty of scrub growing now so give it a few years and it will be an even better place to ride.
(sorry ... bit of an informational hijack there. Nice ride OP ... big fan of Nomads)