Streambank Alteration

1. Using Multiple Indicator Monitoring Protocols Streambank Alteration

2. What is MIM Streambank Alteration? • The number of lines on the plot that intercept hoof prints, hoof shears – disturbances caused by trampling. • 5 lines per frame – one sample • At least 80 samples per site – total of 400+ lines • % Streambank Alteration = the proportion of the 400+ lines that intercept hoof prints/shears

3. MIM Bank Alteration 80+ plots -400 Samples

4. Hoof Print & Hoof Shear Dimensions • Average width = 120.8 mm • Average length =171.8 mm 230mm 120 mm

5. Bank Shear and Tramples

6. Why use a simple intercept method? • Simple = more efficient • Simple = better agreement among observers

7. Variability Among Observers – Various methods • GLP: SD = 4.7, CV = 56 • GL : SD = 6.3, CV = 20 • BF: SD = 8.1, CV = 35 • MIM (35 tests): SD = 4.3 , CV = 22.7 Heitke et.al. 2008

8. MIM estimates length of greenline altered: MIM: 4 “Hits” = 80% LENGTH OF GREENLINE (within 1 hoof print ) altered = 90% AREA OF PLOT altered = 60% Typically the vegetated side of the greenline has fewer alterations

9. Simultation using actual hoof print dimensions

10. Results • Lower Regression Coefficient • 1:3 Relationship (.32 X MIM): • MIM 20% - AREA 10% • MIM 40% - AREA 16% • MIM 60% - AREA 23% • High Regression Coefficient • 1:1 relationship (.91 X MIM)

11. Proper Use of Bank Alteration • As a short-term indicator of disturbance effects on bank stability and vegetation • Any value assigned as a trigger to move livestock or as a measure of grazing use is a “guideline” which must be able to change through time (See Cowley 2002) • Thus a “Term and Condition” should incorporate an adaptive process.

12. Bank Alteration and Bank Stability

13. EF Deer Creek Dominant Vegetation POPR– 65% MFE – 22% JUBA – 12% SCMI – 3% % Hydric – 19% Christopher Christie photo 2008 Sept. 2008 Bank alteration: 24% Bank stability: 51% June 2009 Bank alteration: 4% Bank stability: 67% June 2009 October 2009 Bank alteration:1% Bank stability: 70% Nick Stiner, Malheur NF – Fall 2009

14. Cowley 2002 – Lit Summary • “Little research data is available concerning the amount of streambank alteration that a stream can tolerate and repair each year.” • “Each of the authors mentioned above recognizes the ability of streams to repair a certain amount of bank alteration” • “The further a streambank is from the desired future condition, the less additional alteration it can tolerate and still recover to a stable level.”

15. Amount of Alteration that streambanks can repair annually depends upon: • Stream gradient • Streambed material composition, • Streambank soil composition, • Vegetation cover and type • Channel geometry, • Flow rate and timing, and • “. . . concentrated impacts under rotation systems can cause sufficient woody plant or streambank damage in a single season or year that recovery might take several years. Therefore, the best approach is to limit grazing stress to the site’s capability for annual recovery.” (Clary and Kruse 2004)

16. A Rational Approach to Bank Alteration Criteria and Standards • Existing Condition: Compare existing condition to a reference (best method) • Bank Stability (%): • Bank Cover (%): • Hydric herbaceous vegetation (%) • (closer these are to reference the higher the allowable level of bank alteration) • Channel Type: • >gradient = higher allowable level • > particle sizes = higher allowable level

17. The Confidence Interval • Any criteria requires consideration of the precision of the measurement. • CI for Streambank Alteration • 32 tests • Maximum – 11% • Minimum - .5% • Average – 6% • Using the CI: • Set trigger at allowable level minus 6% • Set standard at allowable level plus 6% • e.g. If allowable level is 20%, trigger might be set at 14%, and term and condition set at 26%.