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
Leaves Terrestrial insects
Riparian Vegetation Functions
Pollutant filtering Fall into stream – large woody debris
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 non-
vegetative stable substrates
Riparian Assessment
Can be broken into 3 sections: 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
Greenline Transect100ft X 5 ft
FLOW
Pool
Gravel bar
Riffle
Zone 1
Zone 2
Zone 3
Riparian Transect100ft X 10ft
Starting point
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
FLOW
Pool
Gravel bar
Riffle
Zone 1
Zone 2
Zone 3Each zone is 10 meters (33 feet) long
Total transect length = 30 meters (100 feet)
Riparian TransectST
REA
M
Length
11 feet
Width
10 feet
Estimate % cover by 10-20 % increments
May have more or less than 100 feet of “riparian zone”
Johnson Creek
175 ft
Measure Slope
Zone 1Zone 2
Zone 3Zone 1
Zone 2
5° 55° 10° 40°25°
Greenline TransectST
REA
M
GREENLINE – the first strip of vegetation along the stream
Length
11 feetWidth
5 feet
Riparian Tree Count
FLOW
Pool
Gravel bar
Riffle
Zone 1
Zone 2
Zone 3 Conifer
Deciduous
Diameter
Circumference
Diameter = Circumference (approx. 3.14)
Tree Size Class
What Does it Tell Us?
Riparian and Greenline Transects Extent and diversity of riparian zone Stability Invasive species
Riparian Tree Count 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
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