While it would not cause world-wide desertification, if you drop enough bombs during the height of the dry season in the middle of a forest with absolutely no adaptation to fire (the Amazon, Congo, or Indonesia etc) and if weather patterns play along you can get a positive feedback loop that may lead to desertification (well, savannah-fication) of large parts of the region. Rainforest trees generally regenerate very poorly in exposed locations and are poorly adapted to the constant drying out from air movement.
After the fires burn out, the trees on the fringes of the burned areas die from wind exposure and won't grow back (although the forest can regenerate over small clearings, larger clearings can't fully recover for many years). Since the forest itself generates much of the rainfall it receives, it gets harder and harder for trees to regrow and the dead spots expand. I remember reading somewhere that parts of the Vietnamese rainforest still hasn't recovered from Agent Orange and napalm. Grass quickly moves in and, because of its flammability, encourages more fires.
It would take a lot of bombs to make a dent in the forests (all those decades of logging haven't caused significant desertification AFAIK), so it's not exactly a very plausible scenario. Grass is much harder to kill since it is already well adapted to fire, regenerates quickly, and plants in general are much more tolerant of mutations than animals (that's how you can have triploid bananas and octaploid strawberries).
After the fires burn out, the trees on the fringes of the burned areas die from wind exposure and won't grow back (although the forest can regenerate over small clearings, larger clearings can't fully recover for many years). Since the forest itself generates much of the rainfall it receives, it gets harder and harder for trees to regrow and the dead spots expand. I remember reading somewhere that parts of the Vietnamese rainforest still hasn't recovered from Agent Orange and napalm. Grass quickly moves in and, because of its flammability, encourages more fires.
It would take a lot of bombs to make a dent in the forests (all those decades of logging haven't caused significant desertification AFAIK), so it's not exactly a very plausible scenario. Grass is much harder to kill since it is already well adapted to fire, regenerates quickly, and plants in general are much more tolerant of mutations than animals (that's how you can have triploid bananas and octaploid strawberries).