I'm not exactly sure what I'm looking at, but my first impression is that you need to mow your under-floor lawn.
Reminds me of a couple of events that happened to me and to a friend of mine. In my case, after a high water encounter, a bunch of twigs and desert scrub were caught on top of the skid plate. In my friends case, he had a gob of grease and oil up there.
For me, after about two weeks, the mud, twigs and brush dried out, then ignited from the heat of the catalytic converter. When I saw the smoke, I was lucky to see a homeowner using a hose to water his front garden. I pulled right up to him, got out and said "I'm on fire! Can I use your hose?" Luckily he handed it to me and I went under the Jeep and put it out. Man, there was a LOT of smoke and actual flames.
In my friends case, his oil mess ignited while driving on the freeway, again with lots of smoke. He pulled over to the shoulder and got out, but had NO fire extinguishing capability with him. Again, luckily, another motorist saw the smoke and stopped. He had a dry-chemical fire extinguisher and let my friend use it. Saved the Jeep!
Obvious lessons learned... 1) Check, maintain and clean and debris anywhere under the Jeep, and 2.) Carry a Fire Extinguisher.
