What is ecological succession?

Ecological succession is the process of ecosystem development over time, which involves a series of gradual changes in the structure and composition of an ecosystem. This concept is crucial in understanding how ecosystems evolve and adapt to both natural and anthropogenic disturbances. Succession can occur in two main forms: primary succession, which happens in lifeless areas devoid of soil, and secondary succession, which occurs in areas where an existing community has been disturbed but soil and some organisms still remain.

During succession, different species colonize an area over time, leading to changes in species composition, diversity, and ecosystem function. Early successional species often alter the environment in ways that make it more hospitable for later species. This process can take many years, resulting in a climax community that is more stable and resilient.

In contrast, the other options describe different concepts. For instance, the immediate response of organisms to environmental changes refers to adaptation or behavioral changes rather than long-term development. A sudden event that alters ecosystems drastically describes disturbances but not the sequential progression of development that defines succession. Lastly, a fixed state of equilibrium in an ecosystem is more akin to the idea of ecological balance, which is not a dynamic process like succession. Therefore, the understanding of ecological succession as a gradual and continuous