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