What is primary succession?

Primary succession refers specifically to the process of ecological development that occurs in an area where no soil exists, such as after a volcanic eruption, glacial retreat, or any event that creates a barren landscape. In such environments, the first organisms to colonize are typically pioneer species, such as lichens and mosses, which can survive in harsh conditions and start to break down the rock substrate, eventually leading to soil formation.

As these pioneer species die and decompose, they contribute organic materials to the environment, enriching it and paving the way for more complex plant and animal communities to establish themselves. Over time, this process can lead to a mature ecosystem, transitioning from simple to more complex communities in a sequential manner.

The other choices refer to concepts related to ecological changes but are not specific to primary succession. For instance, gradual transitions of species can happen in both primary and secondary succession, the introduction of non-native species touches on a different ecological issue, and ecosystem restoration pertains to repairing damaged areas rather than initiating development from scratch. Each of these concepts plays a role in ecology but does not accurately define what primary succession is.