Saturday, January 16, 2010

Pinto Valley Wash - 1/16/10


Remember folks, you saw it here first! On our way out to Lake Mead this morning, we were delayed for several minutes by a one car accident just before the turn-off from Lake Mead Blvd. for the Lava Butte Trail. We are very sad to report that the ambulance went away slowly.

Forty-three hikers came to hike the Pinto Valley Wash whose trailhead is located on Northshore Rd. near mile marker 18. We headed out towards the lake in a wash which was once the old Arrowhead Hwy. that people used as the only "highway" in the 1910's between Los Angeles and Salt Lake City. This particular section of the highway is absolutely beautiful sporting many colors and rock formations.

Above, you can see one place where the highway was shored up to prevent erosion.


The highway wound its way around and between the colorful hills. It is a wonder how long it took people to reach Salt Lake City! And, can you imagine how desolate it must have felt out there in the middle of nowhere? But, there was plenty to look at and this section of the road must have been enjoyed.

After hiking 3 miles in, we stopped for a break before returning the same way we came for a total of 6 miles. There was minimal elevation gain (300-400 feet). Only one place on the hike could be called scrambling and that was a 10'-15' dry waterfall about one mile from the trailhead. Some people hiked around this obstacle but going up and down was doable for most.

The old Arrowhead Highway.

Cryptobiotic Soil Crust

Below, find a portion of an article found in the Arches National Park newspaper which the National Park Service gave out at the gate in July 2005, Vol 1, No.8. It is entitled "Biological Soil Crust."

"...In some places, the ground around and between the widely spaced plants appears to have large patches of dark, knobby, brittle crust. This same scruffy, apparently dead and dried out rind covers almost 75 percent of the ground surface of the 130,000-square-mile Colorado Plateau. It is called biological, or cryptobiotic, soil crust; it is very much alive and of great ecological importance. Soil crust, sometimes called crypto for short, is made up of cyanobacteria, mosses, soil lichens, green algae, microfungi and bacteria.

Cyanobacteria are the most prevalent and most important component. When filaments of cyanobacteria are moistened, they advance through the soil, leaving sheaths of sticky mucilage on their trail. These gluey filaments bind to soil particles and, over time, can create an erosion-resistant surface. Because cyanobacteria is able to capture nitrogen from the air and convert it to a form that plants can use, it serves as a fertilizer - a truly useful trait in an ecosystem notoriously poor in nitrogen. Calcium, potassium and manganese bind to the sheaths and are made available to plants in usable form. When wet, the sheaths will expand to ten times their dry size, enabling the soil crust to retain moisture, to its own benefit as well as that of nearby vascular plants.

In this harsh environment, plants need all the help they can get! Biological crusts provide stable soil, nutrients and moisture. Unfortunately, the interwoven mat of sheath material is easily broken, especially when dry. If you tramp on a well developed patch of crust, you erase decades of growth. The now loose soil underneath often blows over adjacent undamaged patches of cryptos, preventing them from receiving sunlight. No sunlight, no photosynthesis, no cryptos. Unstable sandy soils can turn a nearby solidly anchored, crypto-covered "garden" into a drifting sand dune.

...It is estimated that for a disturbed area of cryptos to become fully functional again, to do all the wondrous things it can, may take as long as 250 years."

The article goes on to ask visitors to take care and avoid the cryptobiotic crust when hiking. This advice can be applied to us in southern Nevada as well.

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