In a pond which change would most likely lead to terrestrial succession?

A significant reduction in water levels in a pond, possibly due to drought or sediment buildup, would likely lead to terrestrial succession. As the pond dries up, the exposed areas would allow for the establishment of wetland and then upland plant species, gradually transforming the habitat from aquatic to terrestrial. This process would encourage the colonization of various terrestrial organisms, leading to a shift in the ecosystem dynamics over time.