What is the process known as when new, lifeless areas of land gradually change into thriving ecosystems?

The process referred to in the question is known as primary succession. This ecological phenomenon occurs in lifeless areas where no soil exists, such as after a volcanic eruption or glacial retreat. During primary succession, the initial colonizers are often pioneer species like lichens and mosses, which can survive in harsh conditions. As these organisms grow and die, they contribute organic matter to the developing soil. Over time, as soil quality improves, a broader range of plants can establish themselves, leading to a more complex ecosystem that includes shrubs and eventually trees.

This process is significant because it lays the foundation for a diverse array of life, transforming barren landscapes into functioning ecosystems over time. The gradual progression from pioneer species to mature ecosystems exemplifies how life can reclaim and adapt to initially inhospitable environments.