1. Disturbance Thresholds for Oregon Evidence from the scientific community

2. The Problem How much sage-grouse habitat can be altered? –What baseline values can we use to regulate disturbance? Where can sage-grouse habitat be altered? When can sage-grouse habitat be altered?

3. Disturbance …”a relatively discrete event in time that disrupts ecosystem, community, or population structure and changes resources, substrate availability, or the physical environment” -- Pickett and White (1985: 7) Categories: Physical (abiotic) Biological (biotic) Human (anthropogenic) Natural Discrete Diffuse Short-term Long-term

4. Disturbance Categories Physical (abiotic) Biological (biotic) Human Natural Discrete Diffuse Short-term Long-term

5. Key Characteristics of Disturbance Intensity Frequency Spatial scale (extent and distribution)

6. Sage-Grouse and Sagebrush Space-time dimensions Shrubs Individuals Populations Sage-Grouse range Management Zone Landscapes Sites Spatial scale (km 2 ) Temporal scale (yr) Leks Core areas 0.1 1,000,000 1,000 1 100 10 1 Stands Management concepts Sage-Grouse Habitat Disturbance space

7. Thresholds 3%??

8. Knick et al. 2013 >3,200 leks across 6 states 90% of leks had >40% sagebrush cover in landscape (mean cover around active leks >78%) 99% of active leks were in landscapes with <3% developed

9. Landscape Thresholds 40% 70 % Matrix Sagebrush

10. Disturbance 3 % 5 % Matrix Sagebrush

11. Landscape Thresholds 37% 65 % Matrix Sagebrush

12. Birds occupy big, flat and undisturbed sagebrush landscapes Baruch-Mordo et al., in press

13. Sage-grouse do best in landscapes with >70% sagebrush “Sagebrush from horizon to horizon”

14. Sage-grouse have trouble persisting in landscapes with <40-50% sagebrush (Knick et al. 2013, Wisdom et al. 2011)

15. Oregon Core Areas = 90% of birds on 38% of the range

16. Take home points Sage-grouse are highly aggregated Multiple factors are related to lek persistence and could be used turned into thresholds, but human disturbance is being used by others –Research suggests that sage-grouse do not tolerate much habitat loss (Knick et al. 2013, Karl and Sadowski 2005, Wisdom et al. 2011) –5% rule in Wyoming based on the footprint of a wellpad in a 1 sq. mile section (Naugle, Doherty) –70/30 ODFW ratio based on Karl and Sadowski 2005, as well as other studies

17. Recommendations Need to specify the extent for applying the disturbance threshold –Will it be at the core area? –Will it be range wide? NTT used two extents –The fine scale helps define when mitigation might be engaged, what the mitigation should be, and where it should occur –Range wide extent ensures long-term persistence of habitat Consider the disturbance regime when considering the extent(s) Define the disturbances that will be included

18. Extra slides

19. Ecological Thresholds

21. Fig. 2 Ecosystem degradation can change the stability domain of ecosystems with multiple stable states to one with only one stable domain. Restoration involves reshaping the stability domains that increase ecosystem resilience (modified from Boesch 2006).