life in wetlands 3

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Peat and Wetlands

  • Definition of Peat: Organic, partially decayed material.

  • Types of Wetlands: Mainly two types of peatlands - Bogs and Fens.

  • Von Post Humidification Scale (H1 to H10):

    • Measures decomposition of organic matter.

    • H1: Least decomposed (visible plant bits) to H10: Most decomposed (liquid gloop).

Sphagnum Moss

  • Role in Peat Formation:

    • Accounts for ~50% of the world's peat.

    • Acts as an Ecosystem Engineer: Modifies environment to suit its needs by creating waterlogged conditions.

    • Absorbs and retains water, inhospitable for decomposition.

  • Chemical Production:

    • Releases trans sphagnum acid, lowering pH and enhancing low pH habitation.

    • Contains phenolics which deter herbivores.

    • Phenolics: Organic compounds contributing flavor (coffee, wine).

Historical Uses of Sphagnum

  • WWI Usage:

    • Dried and shipped for use as wound dressings due to absorbency and sterilizing properties.

  • Prehistoric Evidence: Used for wound dressings and as nappies due to high absorbency.

  • Bulk Bodies: Human remains preserved by peat, showcasing ancient lifestyles—examples include Tollen Man and Lindow Man.

Preservation Mechanism

  • Enzymic Latch Hypothesis:

    • Phenolics inhibit microbial enzymes, halting decomposition.

  • Archaeological Sites:

    • Peatlands preserve ancient organic matter like wooden artifacts.

    • Unique conditions prevent decay, enabling ancient human remains to be uncovered.

Biodiversity and Peatlands

  • Low Biodiversity: Peatlands generally support low diversity in large mammals, amphibians, and reptiles due to nutrient scarcity.

  • Carbon Storage and Climate Impact:

    • Peatlands store up to 545 billion tons of carbon, acting as net carbon sinks.

  • Current Threats: Damage leads to carbon release; UK peatlands emit 23 million tons of CO2 equivalent due to degradation.

Importance of Peatlands

  • Carbon Sequestration:

    • Peatlands contain more carbon than all terrestrial forests combined.

  • Restoration Efforts:

    • Recognition of peatlands' ecological importance is leading to increased conservation efforts, despite ongoing usage in horticulture.

Marshes Overview

  • Definition: Inland, non-tidal wetlands characterized by mineral-based soils and neutral pH.

  • Primary Productivity: High productivity due to good nutrient availability.

  • Plant Types:

    • Grasses: Hollow stemmed, e.g., Phragmites (common reed).

    • Sedges: Solid stemmed with edges, e.g., Sawgrass (sharp-edged).

    • Rushes: Solid, round stems, e.g., Juncus (Soft rush).

Florida Everglades Case Study

  • Described as a "slow moving river of grass".

  • Historical context of wetland drainage and current restoration efforts:

    • Projects to reverse past damage caused by agriculture and drainage.

    • Nutrient loading from adjacent agricultural areas currently affecting biodiversity.

Future Concerns for Everglades

  • Sea level rise and the threat of invasive species (like the Burmese python).

  • The ongoing struggle to balance agriculture and the preservation of natural habitats.