This document summarizes research on using plants and mycorrhizal fungi to control wind erosion. It describes experimental investigations in a wind tunnel that showed reduced sediment mass flux and fine dust concentration with increasing plant density. A plant growth experiment found that mycorrhizal fungi improved plant survival and vitality in dry sandy soils. Further wind tunnel tests assessed how mycorrhizal fungi can reduce soil erodibility. The conclusions state that revegetation measures could be improved by adding mycorrhizal fungi to restore degraded soils and control wind erosion.

1. Plants and Mycorrhizal Fungi in Wind Erosion Control Katrin Burri, Christof Gromke, Frank Graf WSL Institute for Snow and Avalanche Research SLF, Davos, Switzerland International Disaster and Risk Conference IDRC, Davos, 2010

3. Introduction: Wind erosion and desertification Wind erosion gradually converts fertile land into deserts

4. Natural causes: - drought - strong wind - sparse vegetation What are the causes of wind erosion and desertification? Anthropogenic causes: - deforestation, fuelwood-gathering - overgrazing - construction activities

5. - loss of productive soil - loss of biodiversity - air pollution by mineral fine dust What are the consequences of wind erosion and desertification? Human health, lung diseases Global radiation balance, climate change

6. What can be done to stop wind erosion and desertification? ► re-establishing a protective vegetation cover

7. ► poor plant growth and low survival rate due to adverse soil conditions Problem of revegetation measures

8. What can be done to improve the success of revegetation measures? ► Common measures: irrigation, windbreak walls, fertilizing

9. ► Our approach: mycorrhizal fungi What can be done to improve the success of revegetation measures? improvement of plant growth improvement of soil structure

11. Better understanding of the protective effect of plants and mycorrhizal fungi against wind erosion Overall project goal

12. Wind erosion within and above vegetation canopies: A wind tunnel study with live plants

13. 0 plants / m 2 24 plants / m 2 91 plants / m 2 5 plants / m 2 Experimental setup Grass species: Lolium perenne Quartz sand with diameters 0.4-0.8 mm

15. Wind 8 m test section Instrumentation in the wind tunnel Sediment sampler with 60 openings Fine dust measurements

16. 0 plants / m 2 24 plants / m 2 91 plants / m 2 5 plants / m 2 Experimental setup unplanted low vegetation density medium vegetation density high vegetation density

17. Sediment mass flux and fine dust concentration Plants per square meter Total sediment mass flux [kg m -2 min -1 ] PM 10 concentration [mg/m 3 ] Sediment mass flux Fine dust concentration 91 24 0

18. Visualizing erosion and deposition patterns using colored quartz sand Wind

19. Plant growth experiment under simulated eroded soil conditions

20. - To test whether mycorrhizal fungi improve survival rate and vitality of plants grown in dry sandy substrate Research objectives

22. Preliminary results -29.4 -0.8 20.6 11.9 Agrostis capillaris -17.0 -19.1 9.7 3.6 Poa violacea -4.0 -1.3 8.6 0.0 Festuca supina -8.3 -0.8 20.7 5.2 Poa alpina Without drought With drought Without drought With drought Decrease in mortality [%] Increase in vitality [%]

23. Wind tunnel experiments with mycorrhizal fungi

24. - To test whether mycorrhizal fungi reduce the wind erodibility of soil Research objectives

26. Conclusions ► Our laboratory experiments indicate that plants and mycorrhizal fungi offer a promising way to restore soils degraded by wind erosion and desertification. ► The success of revegetation measures may be improved by adding mycorrhizal fungi to the soil.

27. Thank you for your attention!