What are important roles of mosses

Answer: Mosses retain soil humidity and prevents its degradation, besides are habitat for little invertebrates.

Explanation: Mosses are non-vascular plants (they don't have conductive vessels as xylem and phloem) that live places as tree trunks, rocks, walls and soils. This habitats must be humids because mosses need water for nutrient transport, because they don't have cuticle (prevents water lost) and for fertilization. Mosses are important for the ecosistems where they live because retain water in the soils thus prevent erosion and harbor invertebrates as Tardigrades (water bears).