The Costs and Benefits of Using Grazing as a Management Tool to Control Phragmites Autrails in Wetlands: A Project Introduction

1. The Costs and Benefits of Using
Grazing as a Management tool to
Control Phragmites autralis in
Wetlands:
A Project Introduction
Brittany Duncan, Graduate Student in Ecology
Kari Veblen, Assistant Professor, Department of Wildland Resources
Karin Kettenring, Associate Professor, Department of Watershed Sciences
Utah State University, Ecology Center

2. The Problem: Phragmites australis is taking
over Wetlands
 Growth Pattern- Forms Monocultures
 Up to 13ft tall
 Very dense/close growing stems
 Lots of litter
 Reproduces via seeds and
stolens/rhizomes
 Takes advantage of highly nutritious and
disturbed environments
 Outcompetes other wetland plants
 Destroys habitat for wetland birds and
other wildlife
Picture courtesy of:
http://plants.usda.gov/java/largeImage?imageID=phco15_001_avd.tif

3. History
 Introduced in early 1900’s
from Eurasia.
 Utah- More recent
invasion after the mid-
1980 floods
Wiped out native
vegetation, and allowed for
Phragmites to dominate
 Important because the
Great Salt Lake is essential
for migrating birds, and
habitat around it is
dramatically decreasing
Photo courtesy of: http://www.historytogo.utah.gov/utah_chapters/utah_today/floods.html

4. Management
 Managers have yet to find a cost and time efficient method
for management.
 Current Techniques
 Herbicide
 Mechanical Methods
 Burning
 Flooding
 Targeted Grazing- gaining popularity, but not well studied
Picture courtesy of: http://www.invasiveplants.net/phragmites/problem.htm

5. Common Questions
Will cattle eat Phragmites?
YES!! Actually quite
Nutritious
Crude Protein= ~20%
Digestible Dry Matter ranges
from 55-40%
Currently grazed from May to
mid-September
 Health and Safety of Cattle in
Wetlands?
 Sites must be dried out
 Illness and injury can occur (i.e.
Foot rot).
*Best with educated/conditioned
cattle
Photo courtesy of Steve Young and newsromm.unl.edu/announce/beef/2462/13953

6. Thesis
What are the COSTS and BENEFITS of using different grazing
INTENSITIES as a management tool in Wetlands?
1-Plant composition and reproduction
2-Nutrient Cycling
3-Bird density and Species Composition

7. Methods

8. Site Locations
 All located around the Great
Salt Lake
 3 on DWR Wildlife
Management Areas
 At least 1 on Sovereign Lands
(State, Forestry, and Fire)
 Possibly 1 at Bear Rive
Migratory Bird Refuge

9. Sites: Howard-Slough

10. Sites: Crystal at Farmington Bay

11. Sites: Harold Crane

12. Theory: Piosphere
 Definition: The zone of influence of grazing
on a region's vegetation and soil
http://en.wiktionary.org/wiki/piosphere
 "development of a distinct ecological
system in which the interactions are
determined by the existence of the
water-point and by the capacity of the
animals to forage away from the
water-point.”
https://www.zotero.org/groups/savanna_ecology/items/NW4FG65B
 Grazing radius of 2-5 km around
watering points. (Rajabov, 2009);
Large mammals up to 8 km (Thrash
1999); Cattle can be over 2km
(Thrash 1999)
 Tall, thick grass can slow grazing
efficiency
Photo from: http://www.gis.usu.edu/~doug/SERDP/Pubs/SRM2000/

13. Study Design: Theory
Very High
Intensity
High Intensity
Medium
Intensity
Low
Intensity
Very Low to
No Grazing

14. Herbicide Theory: Piosphere
and Herbicide
Herbicide Herbicide

15. Study Design Conti.
 Time Frame:
 2 summers of grazing (Early May-Mid July)
 2 years of Herbicide Treatment
 2 years of monitoring
 5 piospheres (n=5)
 Size 0.25-1 acre
 Measurements taken along a gradient of grazing intensity
 6 plots for data collection per intensity zone
 Total=150 data points

16. Measurements
 Plants
 Biomass
 Reproduction
 Changes in Plant communities/ soil
 Nutrients
 Nitrogen, Phosphorus, Ammonium
 In Soil, Water, Plants, and cow patties
 Microbial Enzymes

17. Conclusion
 Goal: To be able to recommend the best grazing practice for
Phragmites control and wetland restoration
 This study will help unravel the complicated relationship among
wetlands, invasive species, nutrients, and cattle.
 The Piosphere should allow for a cost effective way to display
the relationship at various levels of grazing.
 A very large cooperation between many individuals,
organizations, and disciplines (ranchers, land managers,
professors, students …)

18. Acknowledgements
 Utah Forestry, Fire, and State Lands
 Primary Funders of Project
 Utah Department of Wildlife Resources
 Allowing us to conduct the study on their management areas, and assisting with project
implementation
 Local Ranchers: Ryan Clegg, John Diamond, Matt Marriott, Ed Gilmorr
 Volunteering to participate in project

19. References
 Berger, Randy. 2013-2014. Raw Phargmites nutrient data.
 Hazelton, E.L.G., T.J. Mozdzer, D.M. Burdick, K.M. Kettenring, and D.F. Whigham.
2014. Phragmites australis management in the United States: 40 years of methods
and outcomes. AoB Plants.
 Interviews with Ranchers and Land managers: Ryan Clegg, Matt Marriott, Rich
Hansen, and Chad Cranney
 Mitsch, W.J., and J.G. Gosselink. 2007. Wetlands. John Wiley & Sons, Inc.,
Hoboken, New Jersey. 571p.
 Silliman, B.R, T. Mozder, C. Angelini, J.E. Brundage, P. Esselink, J.P. Bakker, K.B.
Gedan, J. van de Koppel, and A.H. Baldwin. 2014. Livestock as a potential
biological control agent for an invasive wetland plant. PeerJ 2:e567;DOI
10.7717/peerj.567.
 Thrash, I., and J.F. Derry. 1999. The nature and modelling of piospheres: a reviw.
Koe

20. Thanks!!!!!
Photo courtesy of;
http://www.fws.gov/nwrs/threecolumn.aspx?id=21474
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