Final answer:
Primary succession is the sequential colonization of newly exposed or formed land by living things. It starts with pioneer species like lichens and mosses, which break down rock and create soil, allowing other plants to grow and establish a community. Eventually, the community transitions to a climax community with a stable and diverse range of organisms.
Step-by-step explanation:
In primary succession, newly exposed or newly formed land is colonized by living things. This typically occurs after events like volcanic eruptions or glacier retreats. The sequence of stages in primary succession starts with pioneer species, such as lichens and mosses, that have the ability to grow on bare rock. These pioneer species break down the rock and create soil, allowing other plant species to establish themselves. Over time, the community transitions from pioneer species to larger, more complex plants, and eventually reaches a climax community with a stable and diverse array of organisms.
Lichens are often the first pioneer species during primary succession on bare rock, as they help to create the soil needed for further plant colonization. Here is a simplified timeline:
Lava flows into the ocean and forms new land, such as seen on the Big Island of Hawaii.
Weathering and other natural forces break down the substrate, making it possible for pioneer species to establish.
Pioneer species, such as lichens and hearty plants, begin to grow, further breaking down the rock into soil.
The development of soil allows for the colonization by other less hardy species, which will grow and eventually replace the pioneer species.
As species grow and die, they contribute to an ever-growing layer of organic material, enriching the soil.
Over time, this area will develop into a mature ecosystem, reaching an equilibrium with a diverse range of organisms markedly different from the pioneer species.
Each of these stages is important for the development of a stable, biodiverse ecosystem from barren rock or land following events like volcanic eruptions.