Wetland final bruh
1. Wetland Parameters (3 Required Criteria)
To be classified as a wetland, an area must have all three of these features:
Hydric Soils: Soils that are permanently or seasonally saturated, leading to anaerobic (oxygen-deficient) conditions.
Hydrophytic Vegetation: Plants adapted to live in waterlogged soils, like cattails or cypress trees.
Wetland Hydrology: Presence of water at or near the surface for a long enough period to affect the soil and support hydrophytic plants.
2. Plant Adaptations to Anaerobic Stress
Plants must survive oxygen-poor environments using two main strategies:
Avoidance Strategies: Keep oxygen in the root system.
Hypertrophied Lenticels: Swollen areas on stems that facilitate gas exchange.
Aerenchyma: Specialized air-filled channels in stems and roots.
Pneumatophores: "Cypress knees" or aerial roots that draw in oxygen.
Tolerance Strategies: Deal with the stress of anaerobic conditions.
Ethylene Production: Plants release this hormone to trigger certain growth responses.
Enzymatic Breakdown: Enzymes help break down toxic peroxides that accumulate in roots.
3. Wetland Definitions and Regulations
Definition of a Wetland: Areas with hydric soils, hydrophytic vegetation, and wetland hydrology.
Army Corps of Engineers: Gets jurisdiction from the Rivers and Harbors Act and the Clean Water Act.
Clean Water Act: Expanded jurisdiction to "waters of the United States," including wetlands.
1987 Army Corps Wetland Delineation Manual: Defines criteria for wetland identification.
Cowardin Classification: Used by Fish and Wildlife Service for classifying wetlands.
National Wetlands Inventory (NWI) Map: A visual tool that shows the location of wetlands.
4. Wetland Classification (Cowardin System)
Wetlands are classified into systems, subsystems, classes, subclasses, and modifiers.
5 Systems:
Palustrine: Inland freshwater wetlands (like marshes and swamps).
Marine: Ocean-related wetlands.
Riverine: Wetlands along rivers and streams.
Estuarine: Where rivers meet the sea (brackish water).
Lacustrine: Lake-related wetlands.
5. Hydrology and Water Budget
Water Budget: Tracks water inputs and outputs. Inputs include precipitation (P), surface inflow (Si), and groundwater inflow (Gi). Outputs include evapotranspiration (ET) and outflow.
Hydrograph: A graph showing water level changes over time, especially in response to rainfall.
Key Water Characteristics:
Duration of Wetness: How long water stays in the wetland.
Depth of Wetness: How deep the water gets.
Frequency of Wetness: How often water is present.
6. Biological Processes
Denitrification: Conversion of nitrate (NO3-) to nitrous oxide (N2O) or nitrogen gas (N2). Happens only in wetlands because anaerobic conditions are required.
Mineralization: Decomposition of organic matter, releasing nutrients like nitrogen, phosphorus, sulfur, and carbon.
Ammonification: Organic nitrogen (from dead plants/animals) is converted to ammonia (NH3) or ammonium (NH4+).
Nitrification: Occurs in two steps:
Ammonia (NH3) to Nitrite (NO2-).
Nitrite (NO2-) to Nitrate (NO3-).
Nitrification occurs in upland soils (not wetlands) because it requires oxygen.
Nitrogen Fixation: Atmospheric nitrogen (N2) is converted into organic nitrogen by bacteria in plant roots (like legumes).
7. Chemistry Concepts
Iron Reaction (Acid Mine Drainage):
Pyrite (FeS2) reacts with oxygen and water to form sulfuric acid (H2SO4) and ferrous iron (Fe2+).
Wetlands can mitigate this process by neutralizing acidity and capturing metals.
8. Wetland Ecosystem Services
Wetlands provide essential ecological services, such as:
Water Quality Improvement: Filters pollutants like phosphorus, nitrogen, and heavy metals.
Flood Storage: Temporarily stores excess water during storms.
Wildlife Habitat: Provides critical habitat for fish, birds, and amphibians.
9. Autogenic vs. Allogenic Processes
Autogenic Processes: Changes within the wetland caused by internal factors (e.g., plant growth, soil development).
Allogenic Processes: Changes caused by external factors (e.g., floods, sediment deposition, climate change).