Lecture 5 - Hydrology and Physiography of Wetland Habitats

Wetlands

Diverse ecosystems that serve as transitional habitats between terrestrial and aquatic environments, identified by hydrophytic vegetation and hydric soils.

Hydrophytes

Water-loving plants that are characteristic of wetland habitats.

Hydric Soils

Soils rich in organic matter that overlie gray, anaerobic mineral layers, indicative of wetlands.

Inland Wetlands

Wetlands that are found away from coastal areas, including marshes, swamps, riverine wetlands, and peatlands.

Coastal Wetlands

Wetlands located along coastlines and influenced by saline waters, including tidal salt marshes and mangrove swamps.

Tidal Salt Marshes

Wetlands characterized by brackish waters, dominated by grasses and rushes, and influenced by ocean tides.

Mangrove Swamps

Coastal wetlands dominated by salt-tolerant trees (halophytic), found in areas with minimal wave action and sediment accumulation.

Floating Marshes

Wetlands composed of thick mats of roots that float on water, common in river deltas and areas not prone to flooding.

Riparian Wetlands

Wetlands adjacent to rivers, subject to regular flooding, important for nutrient exchange and spawning of fish.

Pothole Wetlands

Marsh ecosystems formed in depressions created by retreating glaciers, crucial for various waterfowl species.

Peatlands

Depressional wetlands characterized by the accumulation of organic matter, acting as critical carbon sinks.

Bogs

Nutrient-poor, acidic wetlands that lack significant water inflow and have lower biodiversity.

Fens

Nutrient-rich wetlands that receive runoff or groundwater inputs and support higher biodiversity.

Hydrologic Regimes

Patterns of water movement in wetlands, including characteristics like permanence, predictability, and seasonality.

Sources of Water in Wetlands

Wetlands derive water from precipitation, surface water, groundwater, and tides.

Subhabitats in Wetlands

Different areas within a wetland that have varying chemical and hydrological characteristics.

Wetlands and Global Change

Wetlands face risks from warming temperatures, changing precipitation patterns, and increased decomposition rates due to climate change.

Ecosystem Services of Wetlands

Functions provided by wetlands, including flood mitigation, water purification, and habitat for diverse species.

Types of Wetlands

Broadly classified into inland and coastal wetlands, further divided by geomorphology, hydrology, and vegetation.

Inland Wetland Types

Includes marshes, swamps, riverine wetlands, and peatlands that are found away from coastal areas.

Coastal Wetland Types

Includes tidal salt marshes, mangrove swamps, and floating marshes found along coastlines and large lakes.

Riverine Wetlands

Wetlands adjacent to rivers characterized by regular flooding and nutrient exchange.

Depressional Wetlands

Low-lying areas that collect water, resembling lakes, often influenced by hydrology and surrounding landscape.

Pothole Wetlands

Small depressional wetlands created by glacial activity, critical for various species, especially waterfowl.

Subhabitats in Wetlands

Distinct zones within a wetland, including littoral, limnetic, and emergent areas, each with unique characteristics.

Littoral Zone

Nearshore areas of a wetland where sunlight penetrates and aquatic plants grow.

Limnetic Zone

Open water areas in a wetland that are deeper and typically contain floating or submerged plants.

Emergent Wetlands

Areas with plants that grow above the water level, often supporting diverse wildlife.

Ephemeral Wetlands

Temporary wetlands that form seasonally, often rich in biodiversity during wet periods.

Biogeochemical Processes

Natural cycles involving the transformation of elements, such as carbon, facilitated by wetland ecosystems.

Wetland Classification Criteria

Wetlands are classified based on their geomorphology, hydrology, climate, nutrient input, and vegetation.

Hydrology's Role in Wetland Types

Hydrology influences wetland characteristics and determines the residence time and movement of water.