Which of the following is NOT a category of wetland biome?

The correct answer is that "Tropical" is not a category of wetland biome. Wetlands are classified into specific biomes based on their vegetation, water chemistry, and hydrology, rather than by broad geographic or climatic regions like "tropical."

Marshes, bogs, and swamps are all recognized types of wetland biomes. Marshes are characterized by herbaceous plants and are often found in areas of shallow water or saturated soil. Bogs are typically more acidic and nutrient-poor, hosting specialized plant species, including sphagnum moss, and are usually formed in cooler climates. Swamps are wetlands that are dominated by woody plants and trees and can be further classified into different types, such as freshwater and saltwater swamps.

In contrast, the term "tropical" describes a climate zone that may contain various biomes, including tropical rainforests and savannas, but it does not define a specific wetland type. This makes "Tropical" the correct choice as the option that does not fit within the established categories of wetland biomes.