Final answer:
Succession is affected by climate, soil, and geography. These factors influence the types of species that can inhabit an area, the soil quality, and the physical characteristics of the landscape which all contribute to ecological succession.
Step-by-step explanation:
Succession is affected by D) all of the above, meaning climate, soil, and geography play roles in this ecological process. The climate influences the types of vegetation and animals that can thrive in a region, while the soil quality, determined by its chemical composition and parent rock, supports the growth of specific plants. The geography, including topography and regional surface features, impacts water runoff and erosion, which in turn affect soil formation and plant growth. Furthermore, succession itself is a sequence of changes in an ecological community over time which can be initiated or altered by these factors.
For example, in primary succession, like on newly formed volcanic islands, no soil exists at first, so early colonizers, such as lichens and mosses, help to break down rock and begin soil formation. In secondary succession, such as after a forest fire, the existing soil supports the regrowth of plants and return of animals. Geography plays a role in both cases, as the topography can influence the water availability and erosion rate, shaping the speed and direction of succession.