Transcript Riparian Vegetation - Bayou Vermilion Preservation Association

Riparian Zone Habitat Assessment
Vegetation and More
What is “riparian vegetation”?
 Plants growing on the streambank and
adjoining floodplain
 Plants in this area are influenced by the water
from the stream
Riparian Zone
Riparian Vegetation Functions
 Roots stabilize banks / reduce erosion
 Provide structure or cover for fish
 Taller vegetation provides shade
 Organic food source for aquatic organisms
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Leaves
Terrestrial insects
Riparian Vegetation Functions
 Pollutant filtering
 Fall into stream – large woody debris
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Shapes channel
Substrate for biological activity
Relationship to Water Quality
 Turbidity / Sediment
 Phosphorus
 Temperature (Shade)
 Nutrient Uptake
 Nutrient Release (Alder)
Two Ways to Assess a
Riparian Zone
Plant Presence
 Habitat Quality
 Actual Diversity
 Invasive Species
 Changes over time
Riparian Assessment
 Stability
 Shade
 Invasive Species
 Large Wood
Recruitment
 Considers nonvegetative stable
substrates
Riparian Assessment
 Can be broken into 3 sections:
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a 100’ riparian transect perpendicular to the
stream,
a 100’ “greenline” transect along the stream,
a riparian tree count performed in a 100 sq ft
area along the stream
Riparian Transect
100ft X 10ft
Zone 3
Zone 2
Starting
point
Zone 1
Greenline Transect
100ft X 5 ft
Riffle
Gravel bar
Pool
FLOW
Riparian Assessment
 Total area = 100 ft x 100 ft (30 m2)
 Instructions in feet and meters
 Starting point is at beginning of first
(downstream) habitat unit
Riparian Transect
Each zone is 10
meters (33 feet)
long
Zone 3
Zone 2
Total transect
length = 30
meters (100
feet)
Zone 1
FLOW
Riffle
Gravel bar
Pool
Riparian Transect
Width
10 feet
Estimate % cover by
10-20 % increments
Length
11 feet
May have more or
less than 100 feet of
“riparian zone”
Johnson Creek
175 ft
Measure Slope
Zone 2
Zone 3
Zone 1
Zone 2
Zone 1
5°
55°
10°
25°
40°
Greenline Transect
GREENLINE – the first strip
of vegetation along the stream
Length
11 feet
Width
5 feet
Riparian Tree Count
Conifer
Zone 3
Deciduous
Zone 2
Zone 1
FLOW
Riffle
Gravel bar
Pool
Tree Size Class
Circumference
Diameter = Circumference
 (approx. 3.14)
Diameter
What Does it Tell Us?
 Riparian and Greenline Transects
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Extent and diversity of riparian zone
Stability
Invasive species
 Riparian Tree Count
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Age-class diversity
Large woody debris recruitment (old growth
conifer, >35”, is MOST desirable)
Evaluation of recruitment
 How many trees of varying size are present
in the riparian zone?
 How close/far are they from the water?
 Over what time period might they become
available?
Large Woody Debris