Final answer:
Mosses contribute to returning nitrogen to the soil through decomposition of moss tissues, releasing nitrogen.
Step-by-step explanation:
Mosses contribute to returning nitrogen to the soil through decomposition of moss tissues which releases nitrogen. As mosses die and decompose, nitrogen is released into the soil, enriching it with this essential nutrient. Mosses do not fix nitrogen from the air or capture nitrogen gas from the atmosphere like some other plants.