Answer:
ecological succession.
Explanation:
The plant may not be present in 25-50 years due to ecological succession. in ecological succession, the vegetation such as small plants that is present replaces by the more suitable vegetation such as trees because the vegetation (small plants) did not receive nutrients and sunlight so they are unable to grow and finally dies due to lack of basic needs. So that's why plant may not be present 25-50 years.
Answer: something that deviates normal
Explanation: I know because I study anomaly
Answer: The vascular plants are set apart in two main ways: Vascular plants have vascular tissues, which circulate resources through the plant. This feature allows vascular plants to grow to a larger size than non-vascular plants, which lack these specialized conducting tissues and are therefore restricted to relatively small sizes.