Plants and the Littoral Zone

Plants and the Littoral Zone

Ecology and Diversity

Growth Habits and Locations of Plant Types in the Littoral Zone

• Emergent Zone

• The Littoral Zone

• Floating-Leaved Zone

• Submergent Zone

• Deep Water or Open Zone

Emergent Macrophytes

• Characteristics:

  • Rooted in the substrate

  • Leaves fully exposed to air

  • Usually rhizomatous: plants that spread via underground stems.

  • Stems and leaves usually have aerenchyma or lacunae: air-filled spaces that facilitate gas exchange.

  • Nutrient uptake: from sediment and inorganic carbon from the air.

Examples of Emergent Macrophytes

• Typha:

  • Commonly known as cattail.

  • Characteristic of wetland communities.

  • Monocot related to grasses.

• Glyceria:

  • Common name: mannagrass.

  • An aquatic grass with rough leaves.

• Phragmites:

  • Known as common reed.

  • Grass that grows aggressively in aquatic and semi-aquatic environments.

• Zizania:

  • Common name: wild rice.

  • Related to the true rice, Oryza.

• Eleocharis:

  • Known as spikerush or spikesedge.

  • Grass-like plant in the sedge family, with spike-like stems without leaves.

• Scirpus:

  • Common name: bulrushes.

  • Resides in the sedge family, with rhizomatous, hollow stems.

  • Leaves associated with subapical inflorescence.

• Carex:

  • Dominant genus of sedges (over 1500 species).

  • Grass-like plants with triangular stem cross-sections.

• Juncus:

  • Known as rush; superficially resembles Eleocharis.

  • Forms tufts of spike-like stems from a basal rosette of leaves.

• Polygonum:

  • Common names: smartweed or knotweed.

  • Characterized by swollen nodes with many species, though only a few are aquatic.

  • Native species often found at margins of lakes, ponds, and rivers.

  • Japanese Knotweed: invasive species found near wet areas but rarely in water.

• Equisetum:

  • Common name: horsetail.

  • The species common in water is E. fluviatile, the river horsetail.

  • Related to ferns.

Floating-Leaved Rooted Macrophytes

• Characteristics:

  • Generally rhizomatous.

  • Floating leaves with a cuticle on the upper surface.

  • Long petiole (leaf stalk).

  • Nutrient uptake: from sediments and inorganic carbon often from both the water and air.

• Nuphar:

  • Common names: spatterdock or cow lily.

  • Rhizomatous with large floating leaves; stems and roots are submerged in mud.

  • Common in aquatic systems throughout the northern hemisphere.

• Nymphaea:

  • Common name: water lily.

  • Similar to Nuphar but with large showy flowers popular in water gardens.

• Brasenia:

  • Common name: watershield.

  • Smaller than Nuphar; stems emerge from the substrate, though technically rhizomatous.

• Nelumbo:

  • Common name: lotus.

  • Resembles Nymphaea with some emergent leaves; one species native to North America.

• Potamogeton:

  • Common name: pondweed.

  • Rooted with elongate stems and floating leaves.

Unrooted Floating-Leaved Macrophytes

• Characteristics:

  • Many have gas-filled floats or tissue; some have entirely aerial leaves.

  • All possess hanging root systems (or modified tissues that function like roots).

  • Nutrient uptake entirely from water, but inorganic carbon sourced from the air.

  • Stems are highly reduced.

• Lemna:

  • Common name: duckweed.

  • Common floating plant throughout the northern hemisphere.

• Wolffia:

  • Common name: water meal.

  • Recognized as the world’s smallest flowering plant, often found alongside Lemna.

• Eichhornia:

  • Common name: water hyacinth.

  • Large free-floating plant from South America that has become a noxious weed in southern US waterways.

• Pistia:

  • Common name: water lettuce.

  • Originally found in Egypt near the Nile, now widespread in tropical and subtropical waterways.

  • It has become a pest in various US waterways.

Free-Floating Unrooted Macrophytes

• Characteristics:

  • Plants are almost entirely submerged but may float at the surface.

  • Leaves tend to be highly dissected.

  • Fragmentation is a major form of reproduction and dispersal.

  • Rarely have roots; nutrient uptake is from water.

• Utricularia:

  • Common name: bladderwort.

  • An aquatic carnivorous plant with more than 250 species globally.

  • Certain species have become pests in some regions.

• Ceratophyllum:

  • Common names: hornwort or coontail.

  • Global in distribution, often found in hard water ponds and lakes.

Submerged Rooted Aquatic Plants

• Characteristics:

  • Leaves are typically highly dissected.

  • Nutrient uptake occurs from both water and substrate.

• Myriophyllum:

  • Common name: water milfoil.

  • Native to Eurasia; become a pest in many still water bodies.

• Elodea:

  • Common name: waterweed.

  • Submerged and native to North America, can root in sluggish streams.

  • Often abundant in nutrient-rich lakes and ponds, commonly used as an aquarium plant.

• Vallisneria:

  • Common names: water celery or tape grass.

  • A rooted plant with broad leaves found frequently in local creeks.

• Isoetes:

  • Common name: quillwort.

  • A fern ally with corm-like bases to leaves; indicative of acid-sensitive waters, sometimes emergent.

• Chara:

  • Common names: muskgrass or skunkweed.

  • A non-vascular plant often found in hard water ponds; many species emit a fetid odor.

• Nitella:

  • Common names: stoneworts or brittleworts.

  • Related to Chara, may occur in soft water ponds; soft to touch due to no calcium carbonate deposition.

Zonation in Ozera Nero

• From the shore to the lake center:

  • Salix (willows)

  • Phragmites

  • Typha

  • Scirpus

  • Equisetum

  • Potamogeton

  • Nuphar

  • Lemna

  • Ceratophyllum

Sam Rayburn Reservoir

• Marginal macrophytes form tight concentric bands consisting of:

  • Nitella

  • Potamogeton

  • Elodea

Imagery Date

• Jun 28, 2005

Main Stem of the Susquehanna River

• Beds of macrophytes found in backwater areas and clear waters of the West Branch, including:

  • Vallisneria

  • Potamogeton

  • Polygonum

  • Elodea

  • Glyceria

Impacts of Macrophyte Dominance

• Effects of dominance include:

  • High primary production.

  • Decreased water turbulence.

  • More efficient nutrient uptake and sequestration compared to algae.

  • Increased water clarity.

  • High organic load.

Heterophylly

• Definition: Many aquatic plant species exhibit differences in leaf shape when submerged or emerged.

  • Mean lobe number or mean blade length (mm):

  • A figure illustrating leaf silhouettes of Ranunculus flabellaris at different temperatures relates to leaf form.

  • Data:

    • Leaf growth varies with temperature (°C): 8, 13, 18, 23, 28 °C.

Reproduction, Dispersal, and Dormancy

• Asexual methods:

  • Example: Potamogeton with winter buds and agamospermy (asexual reproduction without fertilization).

  • Vegetative methods:

  • Example: Myriophyllum.

• Sexual methods:

  • Insect pollination: Example: Nuphar.

  • Wind pollination: Example: Typha.

  • Water pollination: Examples: Potamogeton and Elodea.

Movement of Gases

• Gaseous movement is diffusion-dependent with various mechanisms:

  • Types:

  • Throughflow (convective gas flow) due to thermal transpiration and humidity.

Example Illustration:

• Thermal transpiration across different floating leaf ages, indicating oxygen (O₂) and CO₂ dynamics.

Summary:

• In darkness, respiration leads to increased levels of CO₂; in light conditions, photosynthetic activities utilize water O₂ and increase gas exchange efficiency.

Carbon Uptake

• CO₂ diffusion is slower in water than in air.

  • Unique adaptations include no cuticle in submerged leaves and chloroplasts located in the epidermis of leaves.

  • Some species can decarboxylate bicarbonate; carbon can recirculate within the plant via aerenchyma/lacunae.

CAM Metabolism

• Found in specific aquatic and desert plants, allowing CO₂ uptake at night when inorganic carbon levels are highest in water.

Photosynthetic Efficiency

• Illustrated in relation to light and oxygen dynamics within aquatic macrophytes.

  • Multiple factors such as time of day, dissolved oxygen concentration, and net photosynthesis were analyzed.

Growth or Metabolism Patterns in Aquatic Macrophytes

• Typical growth and metabolic patterns described through seasonal fluctuations in biomass.

• Illustrations detail annual patterns of germination, self-shading effects, and metrics on biomass and productivity.

Biomass Relationships

• Illustrated graphical relationships between aquatic plant biomass and essential nutrient concentrations.

• Analysis includes effects of phosphate and nitrate enrichment on the dominant submerged macrophyte, Scirpus subterminalis.

Data Summary:

• Biomass variations observed due to different nutrient enrichments over time.

Seasonal Variations in Aquatic Macrophytes

• Collection of figures showing shoot density, reproductive cycles, and seasonal maximum biomass.

  • Specific examples include Juncus effusus dynamics over a full year of variation.

Relationship Between pH and Alkalinity

• Notable pH changes linked to submerged macrophyte communities, indicating ecological impacts assessed in Sangwin Pond.

Overview of Littoral Zones in Different Water Systems

• Rivers: Development of land-water interfaces, macrophyte communities, and nutrient acquisition.

  • Dominant types include emergent and floating-submerged macrophytes.

• Reservoirs: Characterized by predominantly rooted emergent plants. Nutrient acquisition primarily through roots.

• Lakes: Well-developed interfaces with diverse macrophyte communities thriving under various nutrient and light conditions.

Summary

• The littoral zone sustains diverse aquatics and reflects varied ecological interactions across different water bodies, influencing macrophyte growth and community structure.

The previous response covered the main concepts and definitions from the document, including characteristics of various macrophyte types, specific plant examples, reproductive methods, carbon uptake mechanisms, and ecological impacts. However, some broader sections like "Growth Habits and Locations of Plant Types in the Littoral Zone" (which is a list of zones), detailed lists of plants in specific reservoirs (like Sam Rayburn Reservoir or Main Stem of the Susquehanna River), or very specific data points (like "Mean lobe number or mean blade length (mm)" or "Imagery Date") were not extracted as individual terms and definitions. The aim was to capture the primary definable concepts and terms presented in the notes.