Recording-2025-01-27T18:50:56.774Z

Aquatic Ecosystems

Horizontal Structure of Lakes

• Similar to oceans, lakes exhibit horizontal structures, primarily the littoral zone and limnetic zone.

• Littoral Zone:

  • Shallow area at the shoreline where rooted plants can grow.

  • Decreases with depth, influencing the types of plants that can thrive based on light availability (important for photosynthesis).

• Limnetic Zone:

  • Extends from the littoral zone into deeper waters of the lake where sunlight is insufficient for plant growth.

  • Characterized as the open lake area.

Temperature Gradients in Lakes

• Like oceans, lakes display temperature stratification.

• Epilimnion:

  • The warm surface layer of the lake.

  • Warm temperatures lead to stratification that affects biological activity and nutrient mixing between layers.

• As depth increases, temperatures drop, influencing organisms' habitats and behaviors.

Human Impact on Aquatic Ecosystems

• Introduced Species:

  • Species such as the lamprey have been introduced to ecosystems, impacting local biodiversity.

  • Introduced species may lead to issues such as eutrophication, worsening water quality.

• Water Pollution:

  • Untreated waste, including sewage, continues to be dumped into lakes, raising concerns about toxins and ecosystem health.

  • Safety recommendations exist for activities like fishing to avoid potential health risks from contaminants such as blue-green algae.

Peatlands

Importance of Peatlands

• Peatlands cover about 15% of Canada and are significant globally, with 80% residing in boreal and subarctic regions.

• Composed of peat, which is decomposed plant material accumulating in poorly drained environments.

Soil Characteristics

• Peatlands feature layers such as the RFH layer (referred to as the red field horizon).

• Nutrient availability is low due to slow decomposition processes, impacting plant life.

Types of Peatlands

• Two main types of peatlands are bogs and fens.

• Bogs:

  • Receive water primarily from precipitation and have acidic conditions.

• Fens:

  • Receive water from surface or groundwater and tend to be less acidic.

Adaptations in Vegetation

• Carnivorous plants like pitcher plants thrive in nutrient-poor peatland ecosystems:

  • These plants evolve to capture insects using pitcher-like structures to supplement their nutrient intake.

  • Slow decomposition rate means essential nutrients like nitrogen are scarce, making these adaptations necessary for survival.

Climate Change

• Climate change is further complicating the health of aquatic ecosystems and peatlands by altering temperature and moisture patterns, which in turn affects both plant and animal life.