1. Plant and fungal community responses to different methods of Brassica removal Riley T. Pratt, Stephanie N. Kivlin, Jessica D. Pratt, Margaret B. Royall, Jennifer M. Talbot Orange County Society for Conservation Biology

2. Speaker Seminar Series Field Trips Restoration Projects & Research www.ocscb.org

3. Upper Newport Bay Ecological Reserve: 752 Acres

4. 4.8 ACRE SLOPE COASTAL SAGE SCRUB NATIVE GRASSLAND INVASIVES: BRASSICA AND ERODIUM SPP.

6. Effects of Brassica Invasion on Ecosystems Alter structure and composition of coastal sage scrub (CSS) Disrupt native fungal communities on which many CSS plant species depend

7. Establishing experimental Brassica removal plots 4 treatments x 4 reps. = 16 plots Treatments: 1.Herbicide (2% glyphosate) 2.Mow 3.Hand-weed 4.Control Treatments applied in Mar & Dec 2009 and Dec 2010 Responses Measured (Spring 2010-2012): Percent cover of all plant species Fungal hyphal length in soil

8. Research Questions How do different methods of Brassica removal impact: 1.Cover of Brassica species? 2.Overall cover of native and exotic vegetation? 3.Plant species composition? 4.Fungal biomass in soil?

9. March 2010: Handweeding suppresses Brassica and promotes native plant cover more than controls Native cover: F 3,15 = 3.93, P=0.036; Brassica cover : F 3,15 = 8.13, P = 0.003; Non-Brassica exotic cover: F 3,15 = 11.65, P < 0.001 Removal Treatments

10. Mowing & handweeding ↓ Brassica and ↑ the native Deindandra fasiculata MRPP T = -7.74, A=0.415, P < 0.0001 Removal Treatments

11. F 3,15 = 3.343, P = 0.038 Brassica removal increases fungal biomass Removal Treatments

12. March 2011: Handweeding suppresses Brassica and promotes native plant cover more than controls Native cover: F 3,15 = 0.8, P=0.511; Brassica cover : F 3,15 = 2.22, P = 0.138; Non-Brassica exotic cover: F 3,15 = 4.29, P =0.028 Removal Treatments

13. January 2012: Handweeding suppresses Brassica and promotes native plant cover more than controls Native cover: F 3,15 = 0.13, P=0.9397; Brassica cover : F 3,15 = 7.2, P = 0.005; Non-Brassica exotic cover: F 3,15 = 7.86, P =0.004 Removal Treatments

14. Summary Herbicide Reduced all plant cover types initially but currently has the highest cover of Brassica Initially increased soil fungi compared to the control Mowing Did not affect Brassica, native, or exotic plant cover Resulted in the greatest initial increase of soil fungi Hand-weeding Most effectively reduced Brassica cover and increased native plant cover. Initially increased soil fungi compared to the control

15. Is hand-weeding worth the effort?

16. Acknowledgements Research, design, data collection: Steve Allison, Bob Reed, Kathleen Treseder, and Numerous OCSCB volunteers Collaborators: Matt Yurko (CCC), Jeff Stoddard (DFG), County of Orange Park and Rec Funding: Sonoran Joint Venture Foundation, Newport Bay Conservancy www.ocscb.org

17. Soil fungi increase when soil nitrate declines Soil hyphal length (mm/g dry soil) % Change in soil NO 3 - after 1 month No treatment Herbicide Hand-weeding Mowing

18. No treatment Herbicide MowedHand-weeded % Change in soil NO 3 - after 1 month

19. Pre-treatment 1 month 3 months No treatment Herbicide MowedHand-weeded Soil NO 3 - (ug N/g soil)