1. The Blooming Desert: Bacteria and Wildflowers Paula R. Gossard July 27, 2005

2. Creating a Wildflower Collection

9. Desert Wildflowers have… Fewer leaves than mountain wildflowers, with any compact foliage closer to the ground Smaller leaves on long, wooly or waxy stems Smaller flowers, with fewer blooms per plant Less variety: 30 specimens in 5 days at four locations vs. 20 specimens in 4 hours at one location

10. Winogradsky Columns A miniature ecosystem that illustrates microbial succession Different organisms grow at different locations in the column, depending on their needs

11. Watering Hole Sediment

13. Cave Extremophiles Sulfur bacteria get their energy from hydrogen sulfide “Snottites” are cave formations composed of bacteria, bacterial “slime” and bits of minerals

14. Biological Soil Crusts Formed by living organisms and their by-products Surface soil particles are bound together by organic materials

15. Biological Soil Crusts Immature crusts are generally flat and the color of the soil; they look like bare ground Mature crusts are usually bumpy and dark-colored due to the presence of many organisms

16. Cyanobacteria, green and brown algae, mosses, lichens, and sometimes liverwort or fungi live in crusts

17. Ecological Roles of Crusts Aid in rainfall absorption Protect soil from erosion and stabilize slopes Contribute nutrients and organic matter to desert soils

18. Cyanobacterial mucilage

20. Human Impact on Crusts Compressional stresses cause great damage to crusts Windborne air pollutants damage crusts Recovery can take from 20-250 years