Riparian Zone Habitat Assessment Vegetation and More What

Riparian Zone Habitat Assessment Vegetation and More

What is “riparian vegetation”? w Plants growing on the streambank and adjoining floodplain w Plants in this area are influenced by the water from the stream

Riparian Zone

Riparian Vegetation Functions w Roots stabilize banks / reduce erosion w Provide structure or cover for fish w Taller vegetation provides shade w Organic food source for aquatic organisms n n Leaves Terrestrial insects

Riparian Vegetation Functions w Pollutant filtering w Fall into stream – large woody debris n n Shapes channel Substrate for biological activity

Relationship to Water Quality w Turbidity / Sediment w Phosphorus w Temperature (Shade) w Nutrient Uptake w Nutrient Release (Alder)

Two Ways to Assess a Riparian Zone Plant Presence w Habitat Quality w Actual Diversity w Invasive Species w Changes over time Riparian Assessment w Stability w Shade w Invasive Species w Large Wood Recruitment w Considers nonvegetative stable substrates

Riparian Assessment w Can be broken into 3 sections: n n n 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 100 ft X 10 ft Zone 3 Zone 2 Starting point Zone 1 Greenline Transect 100 ft X 5 ft Riffle Gravel bar Pool FLOW

Riparian Assessment w Total area = 100 ft x 100 ft (30 m 2) w Instructions in feet and meters w 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

STREAM 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 5° 55° 10° Zone 2 25° 40°

STREAM 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? w Riparian and Greenline Transects n n n Extent and diversity of riparian zone Stability Invasive species w Riparian Tree Count n n Age-class diversity Large woody debris recruitment (old growth conifer, >35”, is MOST desirable)

Evaluation of recruitment w How many trees of varying size are present in the riparian zone? w How close/far are they from the water? w Over what time period might they become available?

Large Woody Debris