Wetlands Study Notes

Definition: Wetlands are areas that are seasonally or permanently waterlogged, supporting hydrophytic vegetation at some point in the growing season.
Coverage: Wetlands cover 6% of Earth's surface and exist in all climatic zones, with local occurrences like the Pantanal, Everglades, and Okavango.

Topographic Situations:
- Basin Wetlands: Develop in shallow basins; water flow is vertical.
- Riverine Wetlands: Found along river banks; water flow is unidirectional.
- Fringe Wetlands: Occur along coasts of large lakes; water flow is two directional.
Vegetation Types:
- Marshes: Dominated by herbaceous plants.
- Swamps: Forested wetlands.
- Bogs: Peatlands depending on precipitation; low nutrient input.
- Fens: Groundwater-fed mires that are nutrient-rich.

Components: Involves water's physical aspects, movement, chemistry, and hydroperiod (duration, frequency, depth, and season of flooding).
Impact: Hydroperiod influences plant composition and growth cycles in wetlands.

Plant Zonation: Wetland vegetation varies with hydroperiod, including:
- Obligate Wetland Plants: Thrive in standing water (e.g., pondweed).
- Facultative Plants: Can grow in both wetland and upland settings (e.g., red maple).
Wildlife: Wetlands support diverse species including fish, amphibians, waterfowl, and various invertebrates.

Threats: Extensive wetland draining for agriculture, development, and pollution (heavy metals, pesticides).
Population Pressure: 70% of people live within 80 km of coastlines, leading to rapid disappearance of coastal wetlands.
Consequences: Loss of wetland habitats jeopardizes water quality, floodwater storage, and biodiversity.

Wetlands play critical ecological roles but face alarming loss from human activities, threatening both environmental and socioeconomic values.