Wetlands & Climate - Chantel Chizen

Overview of Wetlands in Agriculture and Climate Dynamics

  • Definition of Wetlands

    • Classic wetland characteristics: Cattails, ponded water present throughout the year.

    • Agricultural wetlands: May only have water for limited durations (2 weeks to 4 months).

  • Research Focus

    • Impact of dynamic water levels in wetlands influenced by agriculture and climate variability.

    • Research being conducted across prairie regions, particularly involving the areas tied to the Metis homeland.

    • Emphasis on the reflection of landscape management in soil characteristics, symbolizing the state of the land.

Characteristics of Prairie Pothole Wetlands

  • Description

    • Located in the Prairie Provinces of Canada and the Upper Midwest of the United States.

    • Formed during the last glacial period, creating depressions where water accumulates.

    • Timeframe of formation: Wetlands developed 10,000 to 15,000 years ago post-glacial retreat.

  • Wetland Definition

    • Poorly drained soils that accumulate water, vegetation adapted to wetness, and biological activity suited for wet environments.

    • Presence of hydrophilic plants and microbial communities adapted to saturated conditions.

Functions and Importance of Prairie Pothole Wetlands

  • Ecological Functions

    • Habitat and Biodiversity

    • Serve as critical migratory stopovers for birds (spring and fall migrations).

    • Promote unique insect populations that support avian feeding.

    • Water Filtration

    • Act as natural sponges to filter pollutants, toxins, and manage regional water levels during drought and flooding.

    • Nutrient Cycling and Retention

    • High microbial activity supports nutrient cycling and retention, crucial for agricultural operations during droughts.

    • Carbon Storage

    • Wetland soils act as significant carbon sinks, capturing and storing CO₂ from the atmosphere.

Hydrological Dynamics of Wetlands

  • Water Sources and Seasonal Changes

    • Spring flooding from snowmelt fills wetlands, which may dry out by summer due to evaporation/transpiration.

    • Drought can lead to reduced water levels and affect groundwater recharge potentials.

  • Climate Vulnerability

    • Wetlands are sensitive to changing climate patterns influencing precipitation and evapotranspiration rates.

    • Variability in storm events affects the hydrological cycle, impacting wetland health and function.

Wetland Classification

  • Pond Permanence

    • Classification based on how long water remains in a wetland throughout the year.

    • Ephemeral Wetlands: Water present for 2-3 weeks (grasses).

    • Seasonal Wetlands: Water present for approximately 3-4 months.

    • Permanent Wetlands: Water present all year, supporting obligate wetland vegetation like cattails.

  • Vegetation Types

    • Vegetation can indicate wetland type; agricultural landscapes might lack these indicators requiring reliance on pond permanence for classification.

Research Methodology

  • Satellite Imagery

    • Utilization of satellite data to track water presence in wetlands over time; assessment through Normalized Difference Water Index (NDWI).

    • Average water presence evaluated over a minimum of six years to ensure valid classification.

  • Soil Indicators and Microbial Studies

    • Soil characteristics (glaisols, blue/gray/red hues) indicate historical saturation and ecological functionality of wetlands.

    • Research ongoing to determine influential indicators for assessing wetland function and health.

Salinity in Wetlands

  • Salinity Issues

    • Salinity observed in prairie pothole wetlands due to water evaporation, leaving salts behind (bathtub ring phenomenon).

    • Groundwater movement brings salts to the surface, exacerbated by evaporation due to increased drought conditions.

  • Research Initiatives

    • Investigating methods to measure and control salinity influx in wetlands, including the role of vegetation and microbial communities in amelioration.