In areas of permafrost, how does vegetation typically grow?

• A. Vegetation grows only on the surface of the ice, without any soil involvement.
• B. Vegetation grows in a thin active layer of soil that thaws during the summer, while the underlying permafrost remains frozen.
• C. Vegetation roots penetrate deep into the permafrost, allowing for year-round growth.
• D. Vegetation cannot grow at all in permafrost regions due to permanently frozen ground.

Answer: (B)

Verified step by step guidance

1. Understand the concept of permafrost: Permafrost refers to ground that remains frozen for two or more consecutive years. It is common in polar regions and high-altitude areas. The surface layer of permafrost may thaw during the summer, creating an active layer where biological activity can occur.
2. Recognize the role of the active layer: The active layer is a thin layer of soil above the permafrost that thaws during warmer months. This layer allows vegetation to grow temporarily, as it provides access to nutrients and water necessary for plant survival.
3. Consider the limitations of root penetration: Vegetation roots typically cannot penetrate deep into the permanently frozen permafrost. Instead, they grow within the active layer, which is thawed and supports biological processes during the summer.
4. Evaluate the incorrect options: Vegetation does not grow directly on ice without soil involvement, nor does it penetrate deep into the permafrost for year-round growth. Additionally, vegetation can grow in permafrost regions, but only in the active layer during the thawing season.
5. Conclude the correct answer: Vegetation grows in the thin active layer of soil that thaws during the summer, while the underlying permafrost remains frozen. This allows plants to survive in permafrost regions despite the challenging conditions.