Final answer:
Facilitation and tolerance both aid in ecological succession, contributing to the orderly series of changes in an ecosystem after a disturbance. These processes are exemplified in both the maintenance of savanna ecosystems through fire disturbances and the predictable advancement of species during secondary succession in areas with existing soil.
Step-by-step explanation:
The statement is True. Facilitation and tolerance are processes that both contribute to ecological succession, which is the orderly and predictable series of changes in an ecosystem. Facilitation occurs when one species enhances the environment for subsequent species, while tolerance refers to later successional species being less affected by, and hence more tolerant of, the environmental conditions created by earlier species.
In savannas, for example, the dynamic between trees and grasses is maintained by disturbances like fire, which allows for the coexistence of both in the form of a stable balance. Secondary succession, on the other hand, takes place in areas where life and soil pre-exist. In these areas, rich soil allows for the rapid return of species and advancement towards a climax community after a disturbance like fire, without the need for pioneer species such as lichens.
Over time, the ecosystem evolves through various stages, from pioneering to intermediate species, and eventually reaches equilibrium with a climax community characteristic of the climate and geology, although this equilibrium is dynamic and subject to future disturbances and succession stages.