The biology of rarity: Conservation of bryophytes and lichens
Rosentreter, Roger .
Biological soil and crusts and why they are disappearing.
Biological soil crusts are composed of bryophytes, lichens, algae, and cyanobacteria. These crusts were a common component in the arid and semiarid ecosystems of North America. However, the invasion of exotic annual grasses has drastically changed the vegetation dynamics of the many arid regions. Clumped vegetation patterns have been replaced by more continuous annual grasslands. Livestock and human vehicle disturbance has broken the crusts and created a favorable seed bed for exotic annual grasses. Scientists in Idaho have found that biological soil crusts inhibit exotic annuals such as cheatgrass, which minimizes the cover and biomass of this invasive species. This change in cheatgrass distribution patterns greatly influences the risk of fire. Inhibition of annual grasses such as, cheatgrass by biological soil crusts was investigated in the lab after such spatial patterns were observed in the field. The ecological significance of this crust and weedy annual grass interaction is critical to the future of the arid ecosystems.
1 - USDI Bureau of Land Management, Boise, Idaho, 83709
biological soil crusts
Presentation Type: Symposium
Location: Ballroom 3 (Cliff Lodge)
Date: Monday, August 2nd, 2004
Time: 9:30 AM