Living Environment Regents Practice Test

What is a common consequence of ecological succession?

1. An increase in biodiversity over time

2. A decrease in the number of species

3. The introduction of fewer plant types

4. A stable ecosystem with limited changes

The correct answer is: An increase in biodiversity over time

Ecological succession is a natural process through which ecosystems change and develop over time. During this process, a sequence of biological communities replaces one another, leading to an increase in biodiversity. As succession progresses—be it primary (starting from bare rock) or secondary (following a disturbance)—the environment becomes more favorable for diverse plant and animal species. In early stages, pioneer species may arrive, often being hardy organisms that can tolerate harsh conditions. As these pioneers establish themselves, they alter the environment in ways that allow more species to thrive, such as improving soil quality or increasing shade. Eventually, this creates niches that support a wider variety of organisms. As a result, ecosystems typically show enhanced complexity and a greater number of species over time, which is characterized by an increase in biodiversity. This concept underlines the dynamic nature of ecosystems, highlighting how they can evolve and diversify through ecological interactions and adaptations over time.