Riparian Zones Flashcards
What is a riparian zone?
Three dimensional zone of direct interactions between terrestrial and aquatic ecosystems. It mediates the transfer or material and energy. In addition to influencing the physical and ecological characteristics of a stream
Where do headwater streams get most of their organic matter?
From surrounding forest (in first - third order streams) as they can accumulate tonnes of leaf litter
What effects does riparian vegetation have?
Availability of light: Impacts stream temperature and humidity
Bank stability: Roots tie soil together and prevents flows, and stream bank collapses
Provides large woody debris which can impact channel flow, sediment deposits and cause ice dams
How does temperature control everything?
Rate of metabolism, growth, decomposition, gas solubility, ice processes, survival, hatch times. Solar radiation is dominant source of heat and riparian zones impact that by its forest cover (conifer stand has 5% sunlight while a clear cut would have 100%)
What gas does riparian plants remove?
Nitrogen
What is a buffer zone?
An area of fixed width used to protect watershed from human disturbance. NOT A RIPARIAN ZONE! They are often legally required and of 30m. Provincial regulation not federal.
What activities can occur in a buffer zone?
Select harvest up to 30%, No machinery - manual harvest, cutting must be for non marketable value (ex: better view of lake)
What happened when people cut down trees on river edge in 50s/60s?
Damaged aquatic life severely, would cause banks to collapse with lost root stability
Valleys and highlands produce what temp of water?
Valleys: Cold water
Highlands: Warm Water
What is a river?
Linear (more narrow than wide) channel of water with depression and banks. They flow downhill via their topographical gradient
What is brackish water?
It is a mixture of fresh and salt water. A river near an ocean
What are the five influences on hydrology?
Local climate: Rainfall and costal effect
Season: Total precipitation = constant, but in winter water is mainly unavailable
Watershed: Depends on height of land
Morphology: Mouth of rivers will have a lot of sand making multi channels. Sediments are deposited by rivers of glaciers from the past
Land Use: Dams delay flow, irrigation causes less water to make wet fields, oil sands create petroleum deposits
How does cement impact permeability?
Because of its low porosity, cement impacts a waterways discharge and flow rate. 1) By changing geomorphology: causes sandbars and meandering rivers which adds nutrients to the bank 2) Increases volume of water which can cause flooding. This limited water can leave vegetation, fish and mussels exposed :(
What are the two sources of organic carbon in river?
1) Autchtonous inputs: Produced within stream
2) Allochthonous inputs: Produced outside of stream
What are some examples of autchtonous carbon?
Algae, phytoplankton, macrophages, biofilm (periphyton)