Soil Quality in Prairie Dog Towns Presented by Gary Halvorson Sitting Bull College

1. John Hendrickson and Mark Liebig Northern Great Plains Research Laboratory, USDA-ARS Soil Quality in Prairie Dog TownsPresented by Gary Halvorson Sitting Bull College

2. Prairie Dog Basics • There are 5 species of prairie dog although only the black-tailed prairie dog is of importance in the Great Plains • Prairie dogs live in colonies which can be quite large (46,000 acre colony in Mexico) • Social animals that live in groups of 1 adult male and 3-4 adult females and their young (up to 1 year of age).

3. Prairie Dog Basics • Burrows can be deep (> 10 feet in the right soil) extensive (24 feet of tunnel per entrance) and may be located on slightly sloping land. • Burrow entrances are often highly disturbed and may be used as observation points.

4. Prairie Dog Basics • Prairie Dogs impact vegetation

5. Controversial Aspects of Prairie Dogs • Original extent • Estimates of 40 to 100 million ha • Role as Keystone Species • Based on impact on vertebrate populations • Impact on livestock production • Forage reduction estimates range from 4-75% • Derner indicated differences in livestock performance depending on extent in pasture.

6. Where Are We? • Better understanding of above-ground than below ground processes. • Need to understand how we can have wildlife (ie prairie dogs) and livestock coexist.

7. Project Prairie dogs are ‘ecosystem engineers’ Vegetation removal Burrowing activities Very little is known about prairie dog effects on soil quality.

8. Guiding Questions • Do prairie dogs alter soil quality? If so… • At what depth do alterations occur? • At what distance from the hole do alterations extend? • Are depth and distance effects consistent across different soils? AND, MOST IMPORTANTLY… • What are the implications of these alterations to ecosystem function?

9. Field Site and Sampling Plan • Site: McLaughlin Ranch (6 miles SE of McLaughlin, SD) • Soil types: Opal, Cabba, and Wayden • Treatments: Paired on-town, off-town for each soil type • Sampling plan: Intersecting transects over each hole • 30, 60, and 120 cm from hole center • 0-100 cm soil depth (0-10, 10-20, 20-30, 30-60, 60-100 cm increments).

10. = sampling location

11. Cabba Opal Wayden

14. Laboratory Analyses • Physical properties: • Soil bulk density • Residue-associated properties: • Identifiable plant material • Chemical Properties: • Soil pH, electrical conductivity • Extractable N and P • Exchangeable K, Na, Ca, and Mg • Cation exchange capacity • Total C and N, and inorganic C (analyses in progress)

15. Preliminary Results • Alterations concentrated in 0-30 cm depth • Trends in soil properties strongly dependent on distance from hole center • Properties that tend to increase closer to hole… • Extractable N and P; Exchangeable K • Properties that tend to decrease closer to hole… • Soil bulk density; Soil pH

16. Vegetation Aspects • Clipped near the holes that Mark had identified. • 1/8 m frame • 2 frames per hole • Clipped by species 1 m 1 m 1 m 1 m 1 m 1 m

17. Prairie Dog Impact on Productivity • Relatively little change in productivity between prairie dog grazed sites. • Look at difference between prairie dog grazed and non-grazed.

18. Plant Species Number • In general, species numbers were higher on control than the prairie dog colonies except for the Cabba sites. • Still need to look at how these species are distributed

19. Next Steps • Sitting Bull College, NDSU, SDSU and NGPRL-USDA-ARS developed a successful AFRI grant. • This grant is looking at developing a ‘Natural’ meat project on Standing Rock. • A portion of this will be looking at prairie dogs.

20. State and Transition Models—Prairie Dog sites. • Resilience of vegetation on prairie dog colonies. • Can livestock and prairie dogs coexist? • Soils difference • Forage enhancement • Amount of prairie dogs

21. Thank You • John Hendrickson– john.hendrickson@ars.usda.gov • Mark Liebig– mark.liebig@ars.usda.gov