Bio 346 - Freshwater Eco. (Chpt 24) --> Benthic Plants Flashcards
What greatly influences the dynamics of the shallow (littoral) zone of lakes?
Large aquatic plants (macrophytes)
What does the littoral zone include?
- A fraction of sediment (depends on the slope of the the littoral zone)
- Overlying water column (sufficiently illuminated to allow plant growth)
What 3 subdivisions can macrophyte community can be divided into?
- Macroalgae
- Large filamentous and sheet forming algae - Non-vascular plants
- Does not contain phloem or xylem (transporting systems)
Eg) true mosses and bog mosses - Vascular
- Contains both phloem or xylem
Eg) angiosperm
Amphibious plants
Species that grow both in water and on land
Secondary water plants
Species that grow on land and occasionally in water
Erect species
Reach some distance into the water column with a rough uniform biomass distribution along their length
Bottom dwelling species
Species that have most of the biomass near the substratum
What are 3 things macrophytes provide?
Habitat for
- Feeding
- Breeding
- Hading of littoral fish
What are 3 things macrophytes are important suppliers of?
- Organic matter to inland waters
- their decomposition can have a major effect on dissolved O2 [ ]
- Cycling of nutrients and contaminants
What 2 things do canopy macrophytes interfere with?
- Water transport
2. Reduce the underwater light climate
What is a benefit of plants having roots?
They are protected from the wind from being washed ashore
What are 3 species of macrophytes?
- Free floating
- submerged
- Emergent
Wetland
Area saturated with enough water to let plants grow in wet soils
How much does area do wetlands cover?
8.6 km^2 or 6.4% of Earths land area
Where are the most wetlands found?
Boreal forests region of North America and Eurasia
Why are wetlands are valuable?
- Control flooding
- Store water
- Purify water
- Biodiversity
- Recreation
- Culture
Why has about 50% of the wetlands in the USA disappeared?
Mostly due to the drainage for agricultural usage
What led to the creation of dams and draining of wetlands?
Population growth
Bog
Peat-accumulation wetland dominated by mosses
- Bog water is largely acidic (3.5pH), has a low alkalinity and is nutrient poor
Fen
Peat-accumulating wetland receiving some higher alkalinity ground water from a mineral substrate
- As a result the water has a higher nutrient content, neutral pH and supports a marsh-like vegetation
- -> usually dominated by sedges
Marsh
Permanently or periodically inundated wetland characterized by nutrient-rich water and subject to seasonal fluctuations
- The emergent vegetation is adapted to saturated soils and submerging macrophytes are present in deeper waters
Mire
European, synonymous with only peat-accumulating wetlands (bog, fen)
Playa
Shallow marsh-like ephemeral ponds or lagoons in semiarid regions exhibiting appreciable seasonal changes in water level and an elevated salinity
Slough
Marsh or shallow lake system in the northern prairie regions of the US and adjacent Canada
Swamp
Wetlands dominated by trees and shrubs (NA), a forested fen of reed-dominated wetland (Europe), and a tree-or reed-dominated wetland (Africa)
- Temperate zone swamps are fed by nutrient-rich groundwater from primarily mineral sediments
Wet meadow
Grass land or savannah with waterlogged soil near the surface but without standing water for most of the year
Open water
Deeper portions of wetlands and the shallow-water zone (littoral zone) of lakes and rivers, typically inhabited by submerged macrophytes
Why type of macrophyte borders most lowland rivers and dominates wetlands?
Emergent macrophytes
Where do macrophytes grow?
Where the underwater slope is shallow edna re protected from wave-induced turbulence (Littoral zone)
- Allowing plants to root and preventing uprooting
What happens to the number of macrophyte species as the lake size increases?
Increases
- Larger littoral zone
- Greater variability for habitat