Which of the following is common in both primary and secondary succession?

The development of new ecosystems is indeed a shared characteristic of both primary and secondary succession. In primary succession, ecosystems form in an environment devoid of soil, such as after a volcanic eruption or glacial retreat, starting from barren rock. Over time, pioneer species, such as lichens and mosses, colonize the area, leading to the gradual development of soil and eventually a thriving ecosystem.

In secondary succession, which occurs in areas that have been disturbed but where soil and some organisms still exist, the process begins with existing soil that supports quicker plant regrowth. Both types of succession result in the formation of new biological communities, though the starting conditions and rates of development may differ.

In contrast, while destruction of biodiversity can occur during disturbances leading to secondary succession, it isn't a characteristic of the succession process itself. The presence of soil from the outset is unique to secondary succession, and the immediate growth of plants is generally more applicable to secondary succession because it benefits from existing soil. Therefore, the critical aspect that connects both primary and secondary succession is the gradual formation and development of new ecosystems.