It would not be plants, even though it has cell walls. They are not made of chitin. Plants are also not heterotrophic.
Fungi, however, decompose other matter, and have cell walls made of chitin. This would fit the description.
The tropics receive a great amount of direct solar energy, which produces more evaporation<span> than higher latitudes. The warm, moist air rises, condenses into clouds and thunderstorms, and falls back to earth as </span>precipitation<span>.</span>