Final answer:
A tropical rainforest requires a minimum annual precipitation of about 250 cm to sustain its lush vegetation and biodiversity, even though monthly rainfall can vary significantly.
Step-by-step explanation:
About how much annual precipitation is minimally needed to support a tropical rainforest? To sustain a tropical rainforest, a minimal annual precipitation of about 250 cm (98.4 inches) is generally required. This level of moisture supports the lush vegetation and diverse ecosystems characteristic of a tropical rainforest. The annual rainfall in tropical rainforests consists of both wet months, which can receive over 30 cm (about 11-12 inches) of precipitation, and drier months with less than 10 cm (3.5 inches). Despite these variations, even the driest month in a tropical rainforest often receives more rainfall than the total annual rainfall in some other biomes, such as deserts.