Study Notes on Bogs and Fens

Speaker: Michael Hartley
Focus Areas: Definition and characteristics of wetlands, specifically bogs and fens.

Bogs: Specific type of wetland characterized by unique environmental conditions.
Wetlands: General term that includes various ecosystems such as swamps and marshes.
Fens: A type of wetland that is nutrient-rich and often supports a wider diversity of plants.
Swamps and Mires: Related ecological terms that define wetland areas.

Organic Wetlands: Comprise areas where organic material accumulates, prevalent in areas with little decomposition.
Mineral Soil Wetlands: Characterized by mineral soils, support a different ecosystem structure than organic wetlands.
Wetland Classes Include:
    - Bog
    - Fen
    - Swamp
    - Marsh
    - Shallow Open Water
Grouped Wetland Types:
   - Open Wetland Types:
     - Open Bog
     - Open Fen
   - Shrubby Wetland Types:
     - Shrubby Bog
     - Shrubby Swamp
   - Treed Wetland Types:
     - Treed Bog
     - Treed Fen
   - Mudflat Swamp Types:

Bogs:
   - Type: Ombrotrophic (nutrients from precipitation).
   - Hydrology: Rain-fed, leading to nutrient limitation.
   - Environment: Acidic, low plant diversity.
Fens:
   - Type: Minerotrophic (groundwater-fed).
   - Hydrology: Ground-fed with nutrient-rich characteristics.
   - Environment: Neutral to slightly acidic, tends to have a higher plant diversity than bogs.

Geographic Presence:
    - Bogs and fens are predominantly found in Northern climates with low rates of evaporation.
    - Hydrological Differences:
        - Bogs are often hydrologically disconnected from regional groundwater.
        - Fens can be influenced by lake or river water levels, receiving nutrients from seepage.
    - Decomposition Rates: Generally slow, further influencing peatland accumulation and biodiversity.

Level 3 Ecoregions (EPA)
- Example regions: Central Appalachians, Erie Drift Plain, North Central Appalachians, Northern Allegheny Plateau, Ridge and Valley.
- Peatlands highlighted with high confidence in specific regions.

Raised Bogs: Elevated areas of peat accumulation.
Blanket Bogs: Spread over vast areas with varying depth of peat.
Palsas: Frost mounds typical in certain regions; consist of a mixture of peat and ice with surrounding vegetation.

Key Species:
   - S. fuscum
   - S. cuspidatum
   - S. rubellum
Ecological Importance:
   - Most crucial peat-forming genus on Earth with the potential to store about one-third of the entire soil carbon pool globally.
   - Characteristics:
     - Ectohydric, meaning water and nutrients are absorbed and transported externally through capillary action.
     - Can retain 16-26 times its dry weight in water.
     - Contributes to soil acidity through the release of hydrogen ions which can affect surrounding vegetation and water chemistry.

Hyaline Cells: Possible role in water retention and acidifying the environment.
Desiccation Tolerance: Whitened hyaline cells indicate dry conditions, reflecting sunlight and reducing desiccation stress.
Structural Integrity: The developing layers (acrotelm and catotelm) affect the decomposition rates and overall density of peat.

Accretion Rates: Peat accumulation is measured approximately at 6 cm every 100 years in temperate bogs.
Layers:
- Acrotelm: Uppermost layer subject to fluctuating water tables and more significant decomposition.
- Catotelm: Permanently saturated, oxygen-poor layer with extremely slow decomposition processes.
Diversity of Vegetation: Different ecological niches are represented by various mosses, shrubs, and trees best suited to live in these environments.

Nutrient Cycling: Bog shrubs often reabsorb significant amounts of nitrogen (45%-93%) before leaf shedding to conserve nutrients and reduce losses.
Mycorrhizal Associations: Mycorrhizal fungi help roots in peat soils to absorb nitrogen and phosphorus, enhancing nutrient utilization.

Types: Include Pitcher plants, sundews, bladderworts, and Venus flytraps, which utilize prey digestion to gain essential nitrogenous compounds.

Terrestrialization and Paludification:
   - Terrestrialization: Transition from open water to fen and then bog.
   - Paludification: Development of bogs into previously forested landscapes, often induced by climate changes resulting in increased water saturation.

Timeline: Residents have engaged with peatlands since prehistoric times for fishing, forestry, and agriculture, as illustrated by development timelines from Mesolithic to Modern Ages, showing anthropogenic impacts on these ecosystems.

Importance of Peatlands: They play a significant role in carbon storage with estimates of carbon availability across varying depths of peat.

Management Strategies: Various agricultural practices, drainage schemes, and turf cutting have led to ecological changes in peatland systems.