What ecological roles do liverworts mosses and hornworts play in the environment?

They are among the first colonizers of an environment. This way they break down rocks and make nutrients available for other plants. They help in retention of water in a habitat and also shelter many microorganisms. They also decompose organic matter hence play an important role in the cycling of nutrient in the environment.

because the light is a great source of energy for the plants to survive. (i hope this )

the most common type of reef is the fringing reef. this type of reef grows seaward directly from the shore. they form borders along the shoreline and surrounding islands.