Posted by Marcia Penner Freedman
Last week’s post left us with the question of how Sierra meadows protect our health and safety. The answer is simpler than you would imagine:
By controlling the flow of water, season to season.
Intake and outflow, overflow and underflow, water following natural laws of movement from the mountains, directed into streams and rivers that make their way to the San Joaquin Valley, where it is eventually shunted to the canals and reservoirs that supply two-thirds of California homes with water.
As such, Sierra meadows stand out as hydrologic marvels, engineered by nature for efficiency, able to moderate the effects of the seasonal extremes of water flow in the Sierra.
On the one hand they check the oncoming deluge of water during springtime flooding from mountain snowmelt and rainstorms, and, conversely, during the driest, hottest times of the Sierra summers, they move water up from their shallow water table to replenish diminished streams. In addition to recharging streams, the meadows draw water up to feed shallow rooted plants and to restore moisture to the soil during drying out periods.
In a healthy meadow water is continually circulating, entering and leaving. It spreads over the surface and seeps into the ground. Absorbed as if into a sponge, it percolates down through deep layers of moist textured soil and plant material to a shallow groundwater. There, the water is stored amidst a maze of decomposed granite pools, waiting like a dedicated servant to be called upon when needed.
In a striking example of efficiency, in the process of percolation, meadows filter out excess sediment and undesirable nutrients, offering clean clear water to meadow wildlife and to wildlife downstream, as well as to us, the human recipients.
Moist textured soil. Decayed plant life. Underground decomposed granite. These are the key elements that allow the meadow to carry out its many tasks. These structures work together in a delicate balance, sensitive to even slight changes in the environment. The meadow’s hydrologic abilities become threatened if the natural flow of water into the meadow is interrupted or redirected – let’s say, for example, by the presence of tire tracks.
Cutting tire tracks into a meadow could be compared to pouring sand in the truck’s gas tank. The system becomes clogged and shuts down. The ability of the meadow to capture the incoming water and spread it out is decreased. The soil dries out. Inundation during runoff cannot occur. The water passes over the surface unimpeded and the threat of flooding downstream increases.
Underground, meanwhile, the moist textured soil and decayed plants become dry and compacted. Percolation is blocked. Filtering of sediment and undesirable nutrients cannot occur. The natural storage of the water is reduced, and the groundwater table lowers. In the arid summer, streams are unable to draw fresh clean water up, so silty tainted water is transported on to forest streams and rivers.
A year after we discovered the tire tracks in the meadow featured in the wildflower-seeker story, several of us returned and found the imprint of the tracks still present; two pale lines, bare of vegetation, running parallel into the meadow. The deep gouges were gone, but the tracks has filled with compacted soil.
Fortunately, in this case the driver of the truck had backed off before venturing too far into the meadow, so the tracks appear to have had little impact on the water flow. But they stand out as a reminder of the intrusion, an ugly scar in an otherwise healthy meadow of rich dark soil with springs bubbling up from underground, and acres and acres, as far as the eye can see, of green.
And what about the next truck driver? What will he do when he sits at the edge of the meadow, drawn in by the moist, dark soil – in other words, the mud – contemplating his ride, faced with choices?
Let’s try another ‘what-if’ story, different from the one in the wildflower-seeker story:
What if, instead of depressing the gas pedal he keeps his foot on the brake and takes a moment to think? What if, instead of revving the motor he decides to turn it off and step out of his truck? And as he stands at the edge of the meadow, what if his fractured connection to the land gives way, and the truck fades from his mind. And he begins to notice things; movement amongst the grasses or the sounds of buzzing or chirring, or he might catch the sight of a butterfly settling on a flower nearby.
And in his heightened state of awareness what if he enters one of his alternative sensation-seeker worlds, where breaking the law and tearing up Sierra meadows with a pickup truck would be unfathomable. Then, maybe he would put aside his mud desires and his natural inclination for physical challenge and would say to himself, not here, not now.
As the president of an urban 4-wheel drive club said:
My church, the mountains, you step out of your vehicle and it no longer exists. There’s only you and the expanse and the quiet. It draws you in, takes you into its arms and tells you, now you’re where you belong. You can’t put it into words. You have to experience it.