Ecological features of running and standing waters Flashcards
In erosional systems, how are the littoral and central zones distinguished?
There is very little distinction
What type of input dominates erosional systems?
Allochthonous
Describe the biotic community in erosional systems
Epibenthic algae, benthic macro invertebrates, fish
How does high flow impact the biota in erosional systems?
Prevents rooted macrophytes and phytoplankton
How do erosional systems support an aerobic community?
The sediment is coarse and oxygenated.
Give three examples of predatory insects that are attracted by the aerobic biota in erosional systems
Plecoptera (stoneflies), trichopteran (caddisflies), ephemeroptera (mayflies)
What type of habitats are found in erosional systems?
Pool and riffle habitats
Describe pool habitats
Deep, slow-flowing water
Describe riffle habitats
Turbulent (shallow and fast) water flowing over rocks
What is the difference between the littoral and central zones in depositional systems?
Emergent macrophytes in the littoral zones
What is a Riparian Corridor?
The vegetations that grows near a body of water
What happens when the Riparian Corridor is removed from a depositional environment?
Water temperature increases
What type of input is dominant in depositional systems?
Autochontous (although can be even)
What does low flow rate in depositional systems support?
Rooted (benthic) macrophytes
What type of community is found at the littoral zone in depositional systems?
Neuston
Define Neuston
Organisms that live at the water surface
Why do depositional environments have anoxic conditions and what do they support?
Fine sediments result in anoxic conditions, supporting anaerobic heterotrophs
Name four conditions that biological communities have to adapt to in water systems
Substrate, velocity, hard water, dissolved oxygen
Name two characters that biological communities can change to adapt to their environment
Body shape and functional feeding group
Name four functional feeding groups
Shredders, grazers, filterers, predators
Name four adaptations that fish have made to adapt to their environment
Streamlining, use of large stones on substrate, use of refuges, including trees and macrophytes, and variable DO requirements
Name three ways that large allochthonous particles enrich freshwater ecosystems
They can be colonised by bacteria and fungi, provide micronutrients, broken down by shredders
Describe the river continuum concept
A water system is an open ecosystems that is in constant interaction with the bank, is constantly changing, and is always moving from source to mouth.
What does the river continuum concept say about the size of a body of water?
It increases as it moves away from the mouth
What does the river continuum concept say about the transfer of organic matter in freshwater ecosystems?
Organic matter is transferred from erosional areas to deposition areas
How do macro invertebrates react to pollutants?
They have a varied sensitivity and tolerance.
What is the WHPT index used for?
An index of river invertebrate quality
