Freshwater Lakes Flashcards
Key characteristics-
What is lentic?
Standing waters
How are multidirectional flows affected?
By wind direction , speed and convection currents.
What affects stratification?
Temperature and density.
Retention times differ e.g:
Nutrients can be retained for long or short periods of time.
How do pelagic communities fair in freshwater lakes?
They flourish.
How many lakes are in Ireland ?
Over 12,000. 2% of the country’s surface area.
What is the largest lake in Ireland?
Lough Neagh
How are freshwater lakes divided?
Lakes are divided into vertical and horizontal layers based on depth of light penetration.
What is the features of the Littoral zone of freshwater lakes?
- Shallow waters
- Light reaches the bottom
- Stimulates growth of primary producers (PP)
What is the features of the Pelagic zone of freshwater lakes?
- Open waters
- Extends to depth of light penetration
- Microscopic plankton and zooplankton
- Fish
What is the features of the Profundal zone of freshwater lakes?
- Beyond the depth of light penetration
- Dark and cold
- Organisms feed and depend on organic matter from the pelagic zone
What is the features of the Benthic zone of freshwater lakes?
- Bottom region of the lake
- Location of decomposition
What are the dominant physical abiotic factors influencing lakes?
- Light
- Temperature
- Wind, Turbulence and Circulation
How does light influence lakes?
- solar energy is a major energy input to lakes.
- The photic zone , compensation depth and aphotic zone differ based on the light they receive.
What are the features of the photic zone?
- Well lit surfaces
- Net oxygen production by primary producers occurs in the water column
- Includes areas of the littoral,pelagic and parts of the benthic zones.
