Which term best describes the gradual stages of ecological succession on rock?

The term that best describes the gradual stages of ecological succession on rock is xerosere. Xerosere refers specifically to a type of ecological succession that occurs in dry, often rocky environments where the initial pioneer species colonizing bare surfaces, such as lichen and moss, help to create conditions suitable for subsequent plant growth. Over time, as these pioneer species establish themselves, they contribute to soil formation, which allows for more complex plant communities to develop. This process reflects the characteristic stages of succession in arid or semi-arid conditions.

In contrast, hydrosere pertains to succession in aquatic environments, focusing on the development of plant life in water or wetlands rather than on dry rock surfaces. Biomes represent large ecological areas with distinct climates and ecosystems, rather than the processes of succession. Biomechanics is a term that relates to the mechanical principles of biological organisms and does not pertain to ecological succession. Therefore, xerosere is the appropriate term to describe the gradual ecological progression on rocky substrates.