Expect Isolated Afternoon and Evening Thunderstorms Through the Weekend
Monsoonal weather patterns have moved into the Grand Canyon area decreasing fire danger. As a result, on Tuesday, July 8 at 8 a.m. fire managers lifted fire restrictions within Grand Canyon National Park. More »
Two Bats Collected in the Park Have Tested Positive for Rabies
One on the North Kaibab Trail and the other at Tusayan Ruin/Museum. Any persons having physical contact with bats in Grand Canyon National Park, please call 928-638-7779. Rabies can be prevented if appropriate medical care is given following an exposure. More »
Grand Canyon National Park
There is a great deal of exposed rock in and around the Grand Canyon. Much of of that rock is covered by lichens.
A lichen is what one could call a simple biological “community” because it is made up of at least two mutually-dependent organisms. In a lichen, some type of fungi is found along with green algae and /or cyanobacteria.
A lichen community is therefore stronger than either fungus or algae alone. Here's how they help each other out; the green algae uses the photosynthesis process to produce food for the fungus, while the fungus protects the algae from the elements and extracts nutrients from the rocks and soil.
Lichens usually colonize north-facing surfaces since exposure to the sun's heat and radiation is less on north-facing rocks and slopes. Lichens may also grow on healthy, mature cryptobiotic soil crust, and occasionally on live or dead plant material. Many species of lichen are found within Grand Canyon National Park.
Lichens are well adapted to arid climates since they can produce food at any temperature above freezing. Another thing that makes lichens good desert survivors is that they can soak up more than their weight in water. Fungi and green algae are non-vasular plants (without roots and stems) so they can directly soak up dew and rain into their cells.
Colorado River Plant List (280kb Excel Worksheet)
Canyon Sketches Vol 16 - January 2010
Canyon Sketches Vol 06 - October 2008
Did You Know?
California condors, being curious, are attracted to human activity. If you see a condor, do not approach it or offer it food. As you enjoy your next Grand Canyon viewpoint, look for these massive scavengers soaring on their nine-foot (3m) wings over the canyon. More...