Improvement of Meadow Stream Health due to Livestock Distribution Efforts K.W. Tate, T.A. Becchetii, C. Battaglia, N.K. McDougald, D.F. Lile, H.A. George, and D.L. Lancaster

University of California

Grazing – Stream Health

• Grazed streams across CA range from excellent to poor health.

• What practices are associated with excellent to poor health?

• Conduct a cross-sectional survey of health and management of grazed stream systems.

Initial Survey of 128 Rangeland Streams

• Summer of 2000 and 2001.

• Cross-section of the grazed rangeland stream population.

• Cascades, Sierra Nevada, and Coast Range.

• Gradient of stream health and grazing management conditions.

EPA – CDFG Stream Health Assessment Grazing Management

stability Off-site water, herding, season, frequency, fencing, etc.

Site Characteristics

fish habitat macroinverts.

Overall Health Score 0 – 5 poor 6 – 10 marginal 11 – 15 suboptimal 16 – 20 optimal Elevation, channel slope, substrate, watershed disturb., past disturb., etc.

Grazing and Stream Health Associations

• Regression analysis – correlate stream health score (0-20) to grazing management variables • Analyzed by substrate type:

bedrock/boulder, cobble/gravel, fines/alluvial

• Associations v. Cause-Effect

Grazing – Stream Health Score Correlations: Meadow Streams

+ Time maintaining off-stream attractants (days/yr).

+ Herding to reduce time near stream (days/yr).

– Cattle density (AU/ac) .

– Frequency (times/yr).

Follow-up Survey of 58 Streams

• Summer of 2003 and 2004.

• Collect stream macroinvertebrate assemblages.

• Meadow streams (Rosgen C and E).

• Cascades and Sierra Nevada • 3,500 and 8,500 ft elevation.

• Current management in place >10 yr.

Macroinvertebrates

• Integrate stream conditions and disturbance over space and time.

• EPA – CDF&G protocols – 3 transects per 100m reach, d ring kick-net, 0.25 m2 sample area, 3 minute sample effort • ID to genus – species Sub-sample edge and mid stream substrates at 3 transects each stream

Elevation (ft) Pasture / Allotment Area (ac) Herd Size (AU) Off-site Attractants (d/yr) Total Dist. Effort (d/yr) Substrate Type (% sites)

Site Summary

Min.

3,400 800 Mean 5,900 18,000 10 0 0 Fines 53 150 3 9 Gravel 27 Max.

8,500 105,000 670 34 41 Cobble 20

Data Analysis

• • • • • Negative binomial regression (back-step).

Count-based data, skewed towards low values, etc.

Dependents: –

11 macroinvertebrate metrics (11 nbreg models)

–

no. taxa, no. stoneflies, %EPT, etc.

Independents: –

Grazing: dist. effort, rest, AUM/ac/yr, freq., etc.

–

Substrate: fines, gravel, cobble

Cluster Variable:

stream reach

• • • •

11 metrics significantly assoc. with total dist. effort (p<0.10).

No other grazing variables were significant (p>0.10).

Sensitive metrics increased as dist. effort increased.

Substrate a major determinant of 10 metrics.

Select Metrics No. EPT taxa No. Total Taxa No. Intolerant Taxa % Intolerant Taxa % Dominant Taxa Dist. Effort (d/yr)

+

(

p=0.01

)

+

(

p<0.01

)

+

(

p<0.01

)

+ –

(

p=0.06

) (

p=0.03

) Substrate (cobble to fines)

– – – –

(

p=0.07

) (

p=0.02

) (

p=0.02

) (

p=0.06

) n.s.

(

p>0.10

)

Total livestock distribution effort v. richness for streams with fine, gravel, and cobble substrate.

30 Total Taxa 25 20 15 0 10 20 30 Livestock Distribution Effort (days/yr) Cobble Gravel Fines 40

Sensitive metrics decreases with substrate size.

Must be accounted for in cross stream comparisons. 30 25 20 15 10 5 0 Total Taxa Cobble Gravel Fines Streambed Substarte EPT Taxa Intolerant Taxa

•

Distribution effort to reduce time livestock spend near-stream is positively associated with stream health.

•

Relevant to mixed conifer – meadow landscapes, where distribution is inherently a problem.

You got to put in the time to see the benefit… Get along little doggie!