Wow, never imagined a fire could spread even moderately at an altitude of 4000 meters! If you compare the alpine vegetation we have on the Drakensberg peaks here in South Africa, there is only enough fuel for a fire to last for an hour or two Max, before it peters out, and even long before then it will have been reduced to a smoulder
Are there alot of alien invasives on the slopes of Kili?
I focus on helping to ID for the Rest of Africa
Easier for me to help pick out the UNusual stuff, and harder for me to know if it is alien, or simply unknown to me. Satellite view shows a lot of small agricultural plots around the lower slopes.
But it sounds as if the fire is fueled by indigenous forest (honey hunters or runaway camping fires)
Fire is used as an agricultural tool in the páramo in the Andes, and they occur naturally as well, but to a lesser degree. The páramo is a wet grassland and shrub ecosystem in the Andes that is above the tree line and below the permanent snow line. It ranges from around 3,500 meters to well above 4,000 meters, wth some areas reaching up to around 4,700 meters.