some of the tree clumps do show burning but not enough to destroy the whole clump, so there were small localised fires only.
Early images of the debris field showed 'wisps' of smoke among the scattered pieces - as if there had been some smouldering, but little actual 'fire'.
How does atomised aviation fuel burn? We know that fuel tanks burn furiously, but if you rupture the tanks and spray the fuel over a couple of acres . . .